Is nest-site availability limiting Lesser Kestrel populations? A multiple scale approach - Franco, Aldina M. a; Marques, João T.; Sutherland, William J. (Ibis, 2005)
The Lesser Kestrel, a colonial migratory falcon, is one of the most endangered birds in Europe and, due to a sharp population decline across much of the breeding range, is globally threatened. The reasons for this decline are unclear, but reduced nest-site availability might be a major cause. To test this hypothesis we looked at nest-site availability within Portuguese colonies in rural and urban buildings. Nest holes were larger, longer, higher and older than unoccupied cavities. A typical nest cavity was approximately 29–30 cm long, 300–340 cm high and had an inner chamber 16.5–18 cm wide. Large-scale surveys of existing buildings in Portuguese villages suggested that 85% of sites lacked suitable nest cavities. The model for selection of buildings indicated that Lesser Kestrels prefer buildings with many roof and wall cavities, and that are surrounded by extensive cereal and fallow ﬁelds. The villages selected had many old buildings and monuments, were located in areas with few rivers, and a low percentage cover of cereal, olive groves and forest. The conservation implications of these results are discussed.
Keywords: cavities; cereal fields (voyant); Lesser kestrel; nest site availability; old buildings

New aspects of Platypus cylindrus Fab. (Coleoptera : Platypodidae) life history on cork oak stands in Portugal - De Sousa, E. M. R.; Inacio, M. L. (Entomological Research in Mediterranean Forest Ecosystems, 2005)
Platypus cylindrus is an Ambrosia beetle known to attack mainly dead andweakened trees. However, the new outbreak in cork oak stands in Portugal since the 1980's, has led to new hypotheses about the insect - host relationships. Although its biology has been studied since the beginning of the 20(th) century, it is not sufficiently known to enable a quantitative analysis of P. cylindrus population dynamics. Recent studies carried out in Portugal have developed new approaches to the understanding of host selection and colonisation mechanisms, insect bio-ecology and insect-fungus symbiosis. Host selection by P. cylindrus mainly depends on factors associated not only with the stand and tree characteristics (weakness, dimensions) but also with exploitation methods (decorking intensity and period). On the other hand, the colonization process appears to be very structured on the tree surface with a quasi-systematic vertical gradient of density and high rates of attack on the same tree suggesting the presence of aggregation pheromones. The insect life cycle takes place inside the tree over a long period of time and the temporal variability of egg laying results in the coexistence in the galleries of P. cylindrus descendants at different stages. of development. Space management strategies can e responsible for this behaviour. Because of this out of phase life cycle, the emergence period is long (from spring to autumn), and may extend to a second generation during the spring of the following year. The new observed symbiotic associations involving P. cylindrus can be partially understood as an evolution, suggesting that more favourable conditions have been developed. Recent results confirm that P. cylindrus is associated with a complex of six Ambrosia fungi. The presence of pathogenic fungi in the insect galleries suggests that this symbiosis can contribute to the weakness of the host providing the ideal conditions for the insect establishment.
The following values have no corresponding Zotero field: periodical: Entomological Research in Mediterranean Forest Ecosystems pub-location: 147 RUE DE L'UNIVERSITE, 75007 PARIS, FRANCE

Ozone uptake by an evergreen Mediterranean Forest () in Italy. Part I: Micrometeorological flux measurements and flux partitioning - Gerosa, G.; Vitale, M.; Finco, A.; Manes, F.; Denti, A.; Cieslik, S. (Atmospheric Environment, 2005)
Ozone, water and energy ﬂuxes have been measured over a Mediterranean evergreen forest in Central Italy from August to October 2003 with the eddy-correlation technique in order to evaluate the amount of ozone taken up by plants in dry summer and in mild autumn conditions. The stomatal ozone ﬂuxes have been calculated using the analogy with water vapor ﬂuxes inside the stomata, which are easily measurable. The total ozone dose was obtained by integrating the stomatal ﬂuxes over time. Stomatal ﬂux resulted a minor part (31.5%) of the total ozone ﬂux over the forest ecosystem. The main part of ozone deposition follows non-stomatal pathways. Chemical sink seems to play a relevant role in the morning non-stomatal deposition. Stomatal uptake is enhanced by water availability but, on the average, it does not exceed the 34.4% of the total ozone ﬂux. A comparison between the cumulated stomatal ozone ﬂuxes and the currently used AOT40 exposure index highlighted important distortions introduced by this index. AOT40, which do not take into account plant physiology, lead to substantial overestimation of ozone risk, particularly when water supply is limited, as occurs frequently in Southern European and Mediterranean areas.
Keywords: Holm oak; mediterranean forest ecosystem; ozone deposition; Stomatal uptake

Palynology of the northwestern Mediterranean shelf (Gulf of Lions): First vegetational record for the last climatic cycle - Beaudouin, Célia; Suc, Jean-Pierre; Acherki, Nabila; Courtois, Laurent; Rabineau, Marina; Aloïsi, Jean-Claude; Sierro, Fransisco Javier; Oberlin, Christine (Marine and Petroleum Geology, 2005)
Palynology has been performed for the ﬁrst time on Late Quaternary sediments of the Gulf of Lions. The aim is both to tighten the chronology of seismic proﬁles in the region, and to elucidate the vegetation of southern France during the Last Climatic Cycle. Four cores, taken on the shelf, mostly record Marine Isotope Stages (MIS) 1 and 2 and part of MIS 3 and MIS 5. The latter sediments might have been preserved in a paleodepression on the emergent shelf between the Rhoˆne and the He´rault rivers. It would explain their preservation against transgression and regression erosions of more recent stages. This study also provides a synthesis of palynological continental data collected during the last 40 years in southern Europe. Preliminary comparisons made between the latter and new marine data demonstrate that refugia of Picea and Abies existed in southern France during MIS 3 and MIS 2. The dynamics of Artemisia, deciduous Quercus and Corylus, Abies and ﬁnally Fagus is also reconstructed for the last deglaciation. First results obtained in the Gulf of Lions conﬁrm and complete that synthesis.
Keywords: late quaternary; nw mediterranean sea; palynology

Pathogenicity of three Phytophthora spp. causing late seedling rot of Quercus ilex ssp. ballota - Sanchez, M. E.; Andicoberry, S.; Trapero, A. (Forest Pathology, 2005)
Within a research project on quality of plants for forestation of agricultural lands, we studied the aetiology of a late seedling rot affecting holm oak (Quercus ilex ssp. ballota) in two forest nurseries in southern Spain. Major disease symptoms were foliage wilting and necrosis of feeder roots. Phytophthora cinnamomi, Phytophthora cryptogea and Phytophthora drechsleri were isolated from necrotic roots of holm oaks. Selected isolates of the three Phytophthora species were pathogenic to Quercus ilex ssp. ballota and Quercus suber seedlings in artificial inoculations. Soil flooding conditions were essential for infection and root rot development. There was no host specificity among the species, the isolates of P. cinnamomi being the most virulent in all inoculated plants. In these inoculations, Q. ilex ssp. ballota plants were more susceptible than those of Q. suber. This work is the first report of P. cinnamomi, P. drechsleri and P. cryptogea affecting Q. ilex ssp. ballota in forest nurseries.
The following values have no corresponding Zotero field: publisher: Blackwell Verlag GmbH
Keywords: Holm oak; Nurseries (voyant); Phytophthora spp.; root rot; Soil water content

Persistent organic pollutants in cork used for production of wine stoppers. - Mazzoleni, V.; Dallagiovanna, L.; Trevisan, M.; Nicelli, M. (Chemosphere, 2005)
Owing to the lipophilic character of some components of cork and the long periods in the open air (during growth and barks storage), there is a risk of the cork becoming environmentally polluted. Moreover, cork stoppers are in contact with wines for periods ranging from a few months to several years; so they must maintain high levels of hygiene. The present work aims to investigate the level of PCBs, organochlorine pesticides, and PAHs in cork from different countries, used for the manufacturing of one-piece wine stoppers. Samples of cork were analysed using a multi-residue method. PCBs were not detected in all the samples; only a few samples contained detectable amounts of DDE; phenanthrene and anthracene were found in all the samples and fluoranthene in fewer cases. It was not possible to find a significant correlation between POPs concentration and origin of cork. Globally, the detected amounts are consistent with values found in foods, so the investigated cork show a suitable hygienic quality.
The following values have no corresponding Zotero field: accession-num: 15694474
Keywords: Cork; Organochlorine pesticides; PAHs; PCBs

Photosynthetic response of Quercus ilex L. plants grown on compost and exposed to increasing photon flux densities and elevated CO 2 - Arena, C.; Vitale, L.; Santo, A. Virzo De (Photosynthetica, 2005)
Quercus ilex plants grown on two different substrates, sand soil (C) and compost (CG), were exposed to photosynthetic photon flux densities (PPFD) at 390 and 800 µmol(CO2) mol -1 (C390 and C800). At C800 both C and CG plants showed a significant increase of net photosynthetic rate (PN) and electron transport rate (ETR) in response to PPFD increase as compared to C390. In addition, at C800 lower non-photochemical quenching (NPQ) values were observed. The differences between C390 and C800 were related to PPFD. The higher PN and ETR and the lower dissipative processes found in CG plants at both CO2 concentrations as compared to C plants suggest that substrate influences significantly photosynthetic response of Q. ilex plants. Moreover, short-term exposures at elevated CO2 decreased nitrate photo-assimilation in leaves independently from substrate of growth.
Keywords: chlorophyll fluorescence induction; electron transport rate; irradiance; nitrate; non-photochemical quenching; oak

Phytophthora ramorum on Quercus ilex in the United Kingdom. - Denman, S.; Kirk, S. A.; Brasier, C. M.; Barton, V. C.; Hughes, K. J. D.; Webber, J. F. (PLANT DISEASE, 2005)
Phytophthora ramorum causes bleeding cankers of trunks of trees native to the west coast of the United States (i.e., Quercus kelloggii, Q. parvula var. shrevei, and Lithocarpus densiflorus). In the United Kingdom so far, bleeding cankers caused by inner bark infections have been found on Aesculus hippocastanum, Fagus sylvatica, Q. cerris, Q. falcata, and Q. petraea (http://rapra.csl.gov.uk [2005]). Shoot tip dieback (ramorum dieback) and foliar necrosis (ramorum leaf blight) are other diseases caused by the pathogen on understory and ornamental plants (3). Inoculum is produced on infected shoots and leaves of foliar hosts but not on bole cankers (1). Foliar hosts are thus critical in initiating and maintaining epidemics of tree mortality resulting from lethal bark cankers. Ramorum dieback and blight occurs in Europe on genera Rhododendron, Camellia, Kalmia, Pieris, and Viburnum (http://rapra.csl.gov.uk [2005]), and now we report these diseases on foliage and shoots of holm oaks (Quercus ilex) in Cornwall (UK). First discovered in November 2003, infected young leaves had a water-soaked, dull gray appearance, and petioles were blackened. Lesions started at leaf margins, tips, or petioles, often progressing into the midrib veins. Initial infections also occurred on shoots and extended into the petioles. If shoots were infected, they were blackened at first, but later in the season clusters of dry, dead leaves and twigs characterized branch tips. Infected mature leaves bore dry, reddish-brown, restricted lesions. P. ramorum (A1 sexual compatibility type belonging to the European population) was isolated and confirmed by morphological studies, ITS sequence (GenBank Accession No. AY924253), and amplified fragment length polymorphism analyses. Lesions developed on detached leaves dipped for 10 sec in inoculum (4 × 105 zoospores per ml) and incubated in moist chambers at 20°C for 6 days (2). Two isolates were used (four leaves per isolate). The pathogen was reisolated, and the tests were repeated twice. Koch's postulates were also successfully completed once on foliage attached to saplings. To our knowledge, this is the first report of P. ramorum on holm oak. So far, at least 24 holm oaks are infected at various woodland and garden sites in the United Kingdom; infected rhododendrons have also been found at these sites. P. ramorum has also been recorded on saplings in nurseries. The high sporulation potential, the evergreen nature of leaves, and susceptible shoots indicate that holm oak could be a significant source of inoculum for other hosts.
APSAPSThe following values have no corresponding Zotero field: pub-location: 3340 PILOT KNOB ROAD, ST PAUL, MN 55121 USA publisher: AMER PHYTOPATHOLOGICAL SOC
Keywords: pathogens; Phytophthora ramorum; Quercus ilex

Phytostructural characterization of several vegetation types in northern Portugal. II. The structural expressivity and the resistance of the vegetation - Crespí, A.; Bernardos, S.; Castro, A.; Fernandes, C. P.; Amich, F. (Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2005)
Abstract The encouraging results obtained in a previous work induced the authors to pursue here the characterization of the structure of the vegetation in northern Portugal, using the phytostructural methodology proposed earlier by the authors. With this objective, eight different types of vegetal communities, representative of the apparent states of the successional process present in this area, and representing the diversity of plant community types in the same area, were selected. The phytostructural method was elaborated on the basis of three types of structural basic matrices regarding diversity, abundance and cover. The data obtained were collected in a contingency matrix, which was then treated by means of a statistical multivariate analysis. Three structural tendencies emerged from this analysis. With the aim of studying their stability, the results are discussed in terms of resistance and resilience, according to the Highest Expressive Amplitude (HEA) concept, and by considering the intra- and inter-community structural dynamics as structural parameters. The data obtained suggest structural situations with different degrees of non-equilibrium that reflect resistance to environmental factors. The resistance of the vegetation is correlated with the apparent functional connectivity detected for the communities analysed.
doi: 10.1080/11263500500333651doi: 10.1080/11263500500333651The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: Expressive capacity; multivariate analysis; Portugal; structural stability

Post-fire, seasonal and annual dynamics of the ectomycorrhizal community in a Quercus ilex L. forest over a 3-year period. - De Roman, Miriam; de Miguel, Ana María (Mycorrhiza, 2005)
Two study plots, burned and control, were established in autumn 1998 in a Quercus ilex forest located in northern Spain, part of which had been affected by a low intensity fire in 1994. Soil samples for ectomycorrhizae (ECM) were taken over a 3-year period in each study plot in spring, summer, autumn and winter. ECM morphotypes were identified and the relative abundance of each morphotype in each soil sample calculated, along with species richness, Shannon diversity index and percentage of mycorrhization in each soil sample. The relative abundance of certain ECM morphotypes differed between burned and control plots, and the percentage of mycorrhizal tips was significantly lower in the burned than in the control plot. Nevertheless, there were no significant differences in the diversity, species richness or species composition of the ECM community in the burned and control plots. The dominant ECM morphotypes in both stands were Cenococcum geophilum and several thelephoroid fungi. Sphaerosporella brunnea and Pisolithus tinctorius thrived especially in the burned plot, whereas three ectomycorrhizal morphotypes assigned to the genus Hebeloma were especially abundant in the control plot. There was no significant variation in the relative abundance of the ECM morphotypes between seasons, but ECM community species richness was highest in autumn and lowest in summer. The percentage of mycorrhizal tips reached a maximum in winter, with its minimum in autumn. Collection of samples over the 3-year period also enabled us to detect a significant increase in percentage of ECM colonisation in the burned stand over time.
The following values have no corresponding Zotero field: accession-num: 15889285
Keywords: Annual variation; Ectomycorrhizae; Post-fire dynamics; Quercus ilex; seasonal variation

Predicting the Recovery of Pinus halepensis and Quercus ilex Forests after a Large Wildfire in Northeastern Spain - Broncano, Maria José; Retana, Javier; Rodrigo, Anselm (Plant Ecology, 2005)
Quercus ilex and Pinus halepensis are two of the most common tree species of the western Mediterranean basin. Both species regenerate reliably after ﬁre: P. halepensis colonizes recently disturbed areas by eﬀective seedling recruitment, while Q. ilex resprouts vigorously after disturbances. For this reason, the natural regeneration of these species after ﬁre should ensure the re-establishment of a forest similar to that which existed before the ﬁre. This study analyzes with a simple simulation model whether or not the relative abundance of monospeciﬁc and mixed forests of these species in the landscape is altered by ﬁre. We also analyze the topographic factors and the forest structure before the ﬁre that determine the changes in forest composition after ﬁre. This study has been carried out in a large ﬁre that occurred in NE Spain. Overall, 33% of plots changed to another community type, but this probability of change varied considerably among community types before the ﬁre. Monospeciﬁc forests of P. halepensis or Q. ilex had a high probability of remaining in their original composition after the ﬁre, whereas the resilience of mixed forests of these two species was quite low. Mixed forests changed for the most part to monospeciﬁc P. halepensis or Q. ilex forests. Analysis of several factors determining these changes indicated that only elevation as a signiﬁcant topographical variable. The eﬀect of ﬁre was to increase the altitudinal diﬀerentiation between the two species. P. halepensis forests that changed to mixed or Q. ilex forests were those of highest elevation, while the mixed and Q. ilex plots that changed to P. halepensis forests were those located at the lowest elevations. Concerning structural variables before ﬁre, density of Q. ilex trees before the ﬁre showed a much greater eﬀect than P. halepensis density in determining the post-ﬁre community. Finally, burn severity also inﬂuenced the changes observed. For both P. halepensis and Q. ilex forests, plots that changed to another forest type were mainly those that burned more severely. In the case of mixed forests, even low ﬁre severities involved high probabilities of change to monospeciﬁc forests.
Keywords: burn severity; mediterranean forest; natural regeneration; post-fire recovery; resilience

Quality characterization of wine cork stoppers using computer vision - Costa, A.; Pereira, H. (JOURNAL INTERNATIONAL DES SCIENCES DE LA VIGNE ET DU VIN, 2005)
Image analysis techniques were applied on the surface of wine cork stoppers (tops and lateral cylindrical surface) of seven commercial quality classes to characterize their porosity. An increasing trend from the best to the worst quality classes was found for features related to area of pores (i.e. maximum length and width or pore maximum area) and concentration variables (i.e. porosity coefficient or number of pores per 100 cm(2)). Shape variables were rather constant and mean values showed no differences between quality classes. Variation of the pores characteristics within each quality class was large especially in the mid-quality range. Therefore there were no statistically significant differences to allow the isolation of the all quality classes and overlapping was particularly important in the medium-quality classes. The reduction of grading into only three quality classes allowed to isolate statistically different subsets based on porosity coefficient and number of pores per 100 cm(2). These variables can be selected for further development into quality grades specification of wine cork stoppers.
The following values have no corresponding Zotero field: pub-location: 42 RUE MARSAN, 33300 BORDEAUX, FRANCE publisher: VIGNE ET VIN PUBLICATIONS INT
Keywords: computer imaging; quality classes; wine cork stoppers

Quercus suber cork extract displays a tensor and smoothing effect on human skin: an in vivo study. - Coquet, C.; Bauza, E.; Oberto, G.; Berghi, A.; Farnet, A. M.; Ferré, E.; Peyronel, D.; Dal Farra, C.; Domloge, N. (Drugs under experimental and clinical research, 2005)
Recently, it has become indispensable for anti-aging active ingredients to provide a visible and immediate smoothing antiwrinkle effect. In Quercus suber, suberin is the most important structural component of cork cell walls. Studies have shown that suberin is made up mostly of hydroxycarboxylic acids and that it is endowed with many special mechanical and chemical properties that evoke a possible smoothing effect on the surface of the skin. Therefore, we were interested in investigating the effect of this cork extract on the skin's surface in a double-blind clinical study. The study was conducted in 15 healthy volunteers, aged 22 to 52 years. The volunteers applied a gel formula with 3% of cork extract, or placebo gel, on each forearm. Skin surface roughness was evaluated visually by pictures and by silicone replicas 1 and 2 h after application, followed by statistical analysis using the matched-pairs McNemar statistical test. McNemar analysis of the pictures revealed that application of cork extract on the skin resulted in a highly significant reduction of roughness 1 h after application. This effect was observed in 73.3% of volunteers. Two hours after cork extract application, a highly significant improvement of skin roughness was found in 78.6% of volunteers. Moreover, silicone replica treatment confirmed significant improvement in average of roughness at 2 h. These results demonstrate that cork extract provides a remarkable and highly significant tensor and smoothing effect on the skin, which could be of great use in anti-aging skin care products.
Journal Article,Randomized Controlled Trial,Journal Article,Randomized Controlled Trial,The following values have no corresponding Zotero field: pub-location: Vincience Research Center, Sophia Antipolis, France.
Keywords: 2; 3-friedelanol; 6-heptanediol; Quercus suber L.; suberin; Terpens

REFLEXIONES EN TORNO A LA SOSTENlBlLlDAD DE LA DEHESA - Pérez-Díaz, A. (Geographicalia, 2005)
In tlie last century roorii tlie Spanisli deliesa llave wakened up a scien- tific interest tliat he only finds paragon and justification in tlie growing concern of tlie public opinion Sor the conservation and restoration of the environnient. In little time, tlie nieadow has passed of being tlie paradigrn of tlie .'latifun- disruo" in its inost pejorative conception, to hecorne an unquestionahle moclel of sustainable developinent. Witliout denying this new conception a priori; tliis article tries to offer the keys Sor a reflection on tlie last sostenibilidad, present ancl f~ic~ire of the rneadow. And he seeks to make it fi-0111 a geograpliical, inte- grative perspective, far froin íleeting fasliions ancl stereotyped opinions
Keywords: Dehesa; economy; land-use systems; s~istainability

Respuesta plástica a la luz y al agua en cuatro especies del género Quercus - Quero, J. L.; VILLAR, R.; MARAÑON, T.; Murillo, A.; Zamora, R. (IV Congreso Forestal Español, 2005)
El objetivo de este estudio es conocer el nivel de plasticidad fenotípica de plántulas de varias especies de Quercus a dos de los principales factores que regulan el crecimiento y la supervivencia de las plantas leñosas mediterráneas: la luz y el agua, así como determinar qué variables son más plásticas a uno u otro factor. Se cultivaron en condiciones controladas individuos de Quercus ilex subsp. ballota, Q. suber, Q. pyrenaica y Q. canariensis en tres tratamientos de luz (100, 25 y 3% de luz incidente) y con agua abundante. A partir de mediados de primavera, a una parte de los individuos se le suprimió el agua, de forma que se tuvieron dos tratamientos de agua (riego vs. no riego) dentro de cada tratamiento de luz. Se estudiaron distintas variables fisiológicas, como la tasa de fotosíntesis y respiración, el punto de compensación y de saturación a la luz, la conductancia estomática, la eficiencia instantánea en el uso del agua, la eficiencia fotosintética a la luz y la eficiencia en el uso del nitrógeno. También se estudiaron distintas variables morfológicas o estructurales, como el área foliar, el área específica foliar, las concentraciones de N y C y un índice de clorofila. La plasticidad de las variables estructurales al factor agua fue muy baja, mientras que el índice de plasticidad de las fisiológicas fue mayor. Con la luz, no se detectaron diferencias en los índices de plasticidad de las variables estructurales o fisiológicas. Estas diferencias se pueden explicar, por un lado porque la luz es un factor que ha condicionado el crecimiento y expansión de las hojas, afectando tanto a las variables estructurales como fisiológicas. Por el contrario, la falta de agua se puso de manifiesto cuando la planta había finalizado su crecimiento; así no respondieron a este factor modificando características estructurales, de gran componente ontogenético. Sin embargo, estas especies adaptadas a la sequía estival, sí tienen buen potencial de aclimatación a la falta de agua modificando características fisiológicas que le permiten optimizar la relación fotosíntesis/transpiración.
The following values have no corresponding Zotero field: periodical: IV Congreso Forestal Español pub-location: Zaragoza
Keywords: área específica foliar; capacidad fotosintética; eficiencia en el uso del agua; eficiencia en el uso del nitrógeno; plasticidad fenotípica

A revision of the descriptions of ectomycorrhizas published since 1961 - De Roman, Miriam; Clavería, Vanessa; Maria De Miguel, Ana (Mycological Research, 2005)
All available publications providing descriptions of ectomycorrhizas (ECM) were reviewed in order to build a database containing details on fungus forming the ECM, host tree, country where the material for description was collected, and habitat of the ECM. Other secondary data were also recorded. In all 1244 descriptions of ECM published since 1961 in 479 papers were reviewed. The number of diﬀerent ECM morphotypes described was 814. Most ECM described were collected in Europe and North America. Gymnosperms were the most common tree associates, and boreal and temperate forests the most studied ecosystems. Fungal symbionts were mostly Basidiomycota, epigeous, and with mushroom-like morphology. The paper also addresses the gaps in ECM knowledge that mycorrhizologists should address in future studies.
Keywords: descriptions; Ectomycorrhizae; habitat (PG); host tree

Richesse et diversité floristique de la suberaie de la Mamora (Maroc) - Aafi, Abderrahman; KADMIRI, A. A. E. L. (Acta Botanica Malacitana, 2005)
The survey aims to quantify the floristic richeness and diversity of the Mamora’s forest oak-cork ecosystem on the basis of transects and floristic samples distributed according to a stratified and systematic sampling in the different plant formations previously distinguished. The results show that the ecosystem contains 62 families, 261 genders, 408 species, subspecies and varieties : 35 very rare taxa , 29 rare taxa ; 18 endemic taxa, 1 very rare and endemic taxa and 4 rare and endemic taxa. The survey has, otherwise, permitted to reveal the total disappearance of Erica arborea and E. scoparia from this ecosystem and to define the biological spectrum of the studied region, wich is characterized with a clear dominance of therophytes (50.5%).
Keywords: diversity; Mamora; Morocco; Quercus suber; richeness

Root Morphology, Stem Growth and Field Performance of Seedlings of Two Mediterranean Evergreen Oak Species Raised in Different Container Types - Tsakaldimi, M.; Zagas, T.; Tsitsoni, T.; Ganatsas, P. (Plant and Soil, 2005)
Outplanting container-grown oak seedlings with undesirable shoot and root characteristics result in poor establishment and reduced ﬁeld growth. The objective of this study was to determine the inﬂuence of container type on both above-and below-ground nursery growth and ﬁeld performance of one-year old taprooted seedlings Quercus ilex L. and Quercus coccifera L. The experiment was conducted in an open-air nursery and the seedlings were grown in three container types. At the end of the nursery, growth period seedlings shoot height, diameter (5 mm above root collar), shoot and root biomass, root surface area, root volume and total root length were assessed. Then the seedlings were planted in the ﬁeld and their survival and growth were recorded for two growing seasons after outplanting. The results showed a diﬀerence between the Quercus species in the eﬀect of container type. Q. ilex seedlings raised in paper-pot had signiﬁcantly greater height, diameter, shoot and root biomass and root volume than those raised in the other two container types. Similarly, Q. coccifera seedlings raised in paper-pot, had signiﬁcantly greater above-and below-ground growth than those raised in the other two container types. Both oak species showed relatively low survival in the ﬁeld; the mortality was mainly observed the ﬁrst year after outplanting, especially after the summer dry period. However, 2 years after outplanting, the paper-pot seedlings of the two oak species showed better ﬁeld performance.
Keywords: container seedlings; outplanting performance; Quercus coccifera; Quercus ilex; root morphology; stem growth

Root responses of Quercus ilex L. seedlings to drought and fire - Chiatante, D.; Di Iorio, A.; Scippa, G. S. (Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2005)
Abstract Drought treatments in holm-oak (Quercus ilex) seedlings induce variations in total root length, number of root apices, shoot/root dry weight, and root electrolyte leakage. When drought treatments last for more than 50 days a considerable number of fine lateral roots die, irrespective of branching order or distribution within the root system. Scorching of drought-treated seedlings induces a transient stimulation of root growth. These results indicate that root turnover is deeply affected during treatments, with survival of seedlings being entrusted to the tolerance of a number of roots situated in the deeper region of the root system. Activity of the meristematic tissue present within the apices of these surviving roots supports regeneration of above-ground lost organs during recovery. Knowledge of the mechanisms ensuring the survival of Mediterranean tree seedlings following drought and fire is useful for developing models of vegetation dynamics.
doi: 10.1080/11263500500160591doi: 10.1080/11263500500160591The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: Drought; Quercus ilex; root system; seedlings; ﬁre

Rural Changes and Landscape in Serra da Malcata, Central East of Portugal - Coelho-Silva, J. Luís; Castro Rego, Francisco; Castelbranco Silveira, Sofia; Cardoso Gonçalves, C. Paula; Machado, Carlos Alberto (Recent Dynamics of the Mediterranean Vegetation and Landscape, 2005)
This chapter contains sections titled: * Introduction * Methodology and Materials * Results * Discussion
The following values have no corresponding Zotero field: periodical: Recent Dynamics of the Mediterranean Vegetation and Landscape electronic-resource-num: 10.1002/0470093714.ch16
Keywords: campaign credit; forest development policy; Geographical Information System (GIS); land-use dynamics; poly-crop herbaceous system; Portuguese agrarian policies; Portuguese agriculture; private plot; schist-derived soils (citation)

Seasonal changes in photosynthesis and photoprotection in a Quercus ilex subsp. ballota woodland located in its upper altitudinal extreme in the Iberian Peninsula - Corcuera, L.; Morales, F.; Abadia, A.; GIL-PELEGRÍN, E. (Tree Physiology, 2005)
Quercus ilex L. subsp. ballota (Desf.) Samp., a Mediterranean evergreen species growing in a continental Mediterranean climate, did not experience water stress and showed greater sensitivity to winter stress than to summer stress over a 12-month period. Net CO2 assimilation rates and photosystem II (PSII) efficiency decreased markedly during the cold months and recovered completely in spring. Lutein, neoxanthin and β-carotene to chlorophyll (Chl) molar ratios all showed the same trend throughout the year, increasing from September to March. This increase was a result of increases in carotenoid concentrations, because Chl concentration per unit leaf area remained stable, and was higher at the end than at the beginning of the first growing season. Lutein-epoxide was a minor component of the total lutein pool. Thermal energy dissipation and non-photochemical quenching (NPQ) were associated with the de-epoxidated forms of the xanthophyll cycle pigments in the warm months. Photosynthetic rates decreased slightly at midday in summer. These changes were accompanied by decreases in maximum potential PSII efficiency (which recovered during the night), actual and intrinsic PSII efficiencies, photochemical quenching and increases in NPQ. Overall, our data indicate down-regulation of photosynthesis during the summer. The diurnal de-epoxidation of violaxanthin to antheraxanthin and zeaxanthin occurred throughout the year, except in January. Antioxidant enzymatic activity increased in the winter months, especially during the coldest months, highlighting its key role in photoprotection against photo-oxidation. Structural and functional modifications protected PSII from permanent damage and allowed 1-year-old leaves to photosynthesize at high rates when temperatures increased in spring.
10.1093/treephys/25.5.59910.1093/treephys/25.5.599
Keywords: antioxidant enzymatic activity; chlorophyll fluorescence; photosynthetic pigments; summer stress; winter stress

Seasonal changes in the thermal environment do not affect microhabitat selection by Psammodromus algirus lizards - Diaz, J. A. (The Herpetological Journal, 2005)
We studied the thermal consequences of microhabitat selection by Psammodromus algirus lizards by combining data on the frequency of use and relative availability of three different types of microhabitats, with information about the environmental operative temperatures, and their deviations from the lizards' selected thermal range, available in these microhabitats. In both seasons, lizards preferred holm oak shrubs and avoided rockrose shrubs and open areas. However, the thermal suitability of holm oaks was highest in July but lowest in May. We suggest that microhabitat preferences were more related to other aspects of lizard ecology (e.g. antipredator behaviour) than to thermal requirements.
Keywords: lizard; operative temperatures; predation risk; thermoregulation

SEASONAL PATTERN OF PHYSIOLOGICAL STATE IN A CORK OAK (QUERCUS SUBER L.) STAND IN HUELVA (SPAIN) - GONZÁLEZ-PÉREZ, ARANTZAZU; VÁZQUEZ-PIQUÉ, JAVIER; TAPIAS, RAÚL; FERNÁNDEZ, MANUEL (Suberwood2005: New challenges for integration of cork oak forests and products, Scientific and Technical Conference, Huelva, Spain, 20, 21 and 22 October 2005., 2005)
The seasonal pattern of the physiological state of Quercus suber is determined by different ecological factors, and it affects to the growth of the species. The main objective of this study is to know the seasonal pattern of water potential, photosynthesis and fluorescence in four Quercus suber L. trees and to relate these values with ecological factors during two years. In this time there were three critical periods, the first one the end of the dry period where the water potential descends to values less than -3MPa and the photosynthesis to 0.781 µmol CO2m-2 s-1Quercus suber, physiology, water potential, photosynthesis, fluorescence. . The second critical period is located in period of change of the leaf, between the months of March and May. The third critical period occurred due to the freezes and drought of the year 2005, that produced strong damages in the PSII.
The following values have no corresponding Zotero field: periodical: Suberwood2005: New challenges for integration of cork oak forests and products, Scientific and Technical Conference, Huelva, Spain, 20, 21 and 22 October 2005. pub-location: Huelva
Keywords: fluorescenc; photosynthesis; physiology; Quercus suber; water potential

Sicily represents the Italian reservoir of chloroplast DNA diversity of Quercus ilex L. (Fagaceae) - Fineschi, Silvia; Cozzolino, Salvatore; Migliaccio, Marianna; Musacchio, Aldo; Innocenti, Michela; Vendramin, Giovanni G. (Ann. For. Sci., 2005)
Chloroplast DNA polymorphism was analysed in forty-four Italian holm oak populations. Results obtained with different markers (PCR-RFLP and SSR) were congruent, showing a clear geographic structure of genetic diversity and high value of genetic differentiation (Gst = 0.80). By combining PCR-RFLP and SSR, eight haplotypes were identified in Italy, six of them in Sicily. Most populations were fixed for one haplotype. Some populations from the extreme West Mediterranean (Morocco) and the extreme East Mediterranean areas (Crete) were interpreted as reproductively isolated populations because they had completely different haplotypes. These results strongly support the hypothesis of glacial refugia existing in southern Italy, and underline the high conservation value of natural tree populations in Sicily, in which most diversity was detected.
Keywords: genetic differentiation; PCR-RFLP; Quercus ilex; SSR

Site quality evaluation by classification tree: an application to cork quality in Sardinia - Corona, Piermaria; Dettori, Sandro; Filigheddu, Maria Rosaria; Maetzke, Federico; Scotti, Roberto (European Journal of Forest Research, 2005)
Cork harvesting and stopper production represent a major forest industry in Sardinia (Italy). The target of the present investigation was to evaluate the ‘‘classiﬁcation tree’’ as a tool to discover possible relationships between microsite characteristics and cork quality. Seven main cork oak (Quercus suber) producing areas have been identiﬁed in Sardinia, for a total of more than 122,000 ha. Sixty-three sample trees, distributed among diﬀerent geographical locations and microsite conditions, were selected. A soil proﬁle near each sample tree was described, soil samples were collected and analysed. After debarking, cork quality of each sample tree was graded by an independent panel of experts. Microsites where trees had more than 50% of the extracted cork graded in the best quality class, according to the oﬃcial quality standard in Italy, were labelled as prime microsites, the others as nonprime microsites. Relationships between a binary dummy variable (0 for nonprime microsites, 1 for prime microsites) and site factors were investigated using classiﬁcation tree analysis to select the relevant variables and to deﬁne the classiﬁcation scheme. Prime quality microsites for cork production proved to be characterised by elevation, soil phosphorus content and sandiness. Results have been compared with those of the more conventional parametric approach by logistic regression. The work demonstrates the advantages of the classiﬁcation tree method. The model may be appropriate for classiﬁcations at landscape and stand mapping levels, where it is possible to sample a number of microsites and to evaluate distributional characteristics of model output, while its precision is only indicative when estimating the prime quality of single microsites.
Keywords: Classiﬁcation tree; Cork quality; Logistic regression; Quercus suber; Site classiﬁcation and evaluation

Summer and winter sensitivity of leaves and xylem to minimum freezing temperatures: a comparison of co-occurring Mediterranean oaks that differ in leaf lifespan. - Cavender-Bares, J.; Cortes, P.; Rambal, S.; JOFFRE, R.; Miles, B.; Rocheteau, A. (The New phytologist, 2005)
Freezing sensitivity of leaves and xylem was examined in four co-occurring Mediterranean oaks (Quercus spp.) grown in a common garden to determine whether freezing responses of leaves and xylem were coordinated and could be predicted by leaf lifespan. Freezing-induced embolism and loss of photosynthetic function were measured after overnight exposure to a range of subzero temperatures in both summer and winter. Both measures were found to be dependent on minimum freezing temperature and were correlated with leaf lifespan and vessel diameter. The dependence of xylem embolism on minimum freezing temperature may result from the decline in water potential with ice temperature that influences the redistribution of water during freezing and leads to an increase in xylem tension. Winter acclimatization had a relatively small effect on the vulnerability to freezing-induced embolism, although leaf photosynthetic function showed a strong acclimatization response, particularly in the two evergreen species. Quercus ilex, the species with the longest leaf lifespan and narrowest vessel diameters, showed the highest freezing tolerance. This helps explain its ability to inhabit a broad range throughout the Mediterranean region. By contrast, the inability of the deciduous oaks to maintain photosynthetic and vascular function throughout the winter indicates a competitive disadvantage that may prevent them from expanding their ranges.
The following values have no corresponding Zotero field: accession-num: 16313643
Keywords: cold acclimatization; decline in F V /F M; freezing-induced embolism; leaf lifespan; minimum temperatures; xylem anatomy

Temporal variations in PAH concentrations in Quercus ilex L. (holm oak) leaves in an urban area. - De Nicola, Flavia; Maisto, Giulia; Prati, Maria Vittoria; Alfani, Anna (Chemosphere, 2005)
Temporal variations of polycyclic aromatic hydrocarbon (PAH) concentrations in leaves of a Mediterranean evergreen oak, Quercus ilex L., were investigated in order to assess the suitability of this species to biomonitor PAH air contamination. Leaf samples were collected at six sites of the urban area of Naples (Italy) and at a control site in the Vesuvius National Park, in May and September 2001, and in January and May 2002. PAH extraction was conducted by sonication in dichloromethane-acetone and quantification by GC-MS. In winter, leaf total PAH concentrations showed, at all the urban sites, values 2-fold higher than in all the other samplings, reflecting the temporal trend reported for PAH air contamination in the Naples urban area. Moreover, leaf PAH concentrations showed, at all the urban sites, a decrease in May 2002 after the winter accumulation. At the control site leaf PAH concentrations showed lower values and smaller temporal variations than at the urban sites. The findings support the suitability of Q. ilex leaves to monitor temporal variations in PAH contamination. The highest winter concentrations of total PAHs were due to the medium molecular weight PAHs that increased with respect to both low and high molecular weight PAHs. The medium molecular weight PAHs showed the same temporal trend both at the urban and remote sites.
The following values have no corresponding Zotero field: accession-num: 16182861
Keywords: Aromatic; Aromatic: analysis; Cities; Environmental Monitoring; Environmental Pollutants; Environmental Pollutants: analysis; Italy; Mediterranean evergreen oak; Naples (Italy); PAH biomonitoring; pah leaf accumulation; Plant Leaves; Plant Leaves: chemistry; Polycyclic Hydrocarbons; Quercus; Quercus: chemistry; Seasonal trend; Seasons; Time Factors

The use of climatic parameters and indices in vegetation distribution. A case study in the Spanish Sistema Central. - Gavilán, Rosario G. (International journal of biometeorology, 2005)
In this study, over 100 phytoclimatic indices and other climatic parameters were calculated using the climatic data from 260 meteorological stations in a Mediterranean territory located in the centre of the Iberian Peninsula. The nature of these indices was very different; some of them expressed general climatic features (e.g. continentality), while others were formulated for different Mediterranean territories and included particular limits of those indices that expressed differences in vegetation distribution. We wanted to know whether all of these indices were able to explain changes in vegetation on a spatial scale, and whether their boundaries worked similarly to the original territory. As they were so numerous, we investigated whether any of them were redundant. To relate vegetation to climate parameters we preferred to use its hierarchical nature, in discrete units (characterized by one or more dominant or co-dominant species), although it is known to vary continuously. These units give clearer results in this kind of phytoclimatic study. We have therefore used the main communities that represent natural potential vegetation. Multivariate and estimative analyses were used as statistical methods. The classification showed different levels of correlation among climatic parameters, but all of them were over 0.5. One hundred and eleven parameters were grouped into five larger groups: temperature (T), annual pluviothermic indices (PTY), summer pluviothermic indices (SPT), winter potential evapotranspiration (WPET) and thermal continentality indices (K). The remaining parameters showed low correlations with these five groups; some of them revealed obvious spatial changes in vegetation, such as summer hydric parameters that were zero in most vegetation types but not in high mountain vegetation. Others showed no clear results. For example, the Kerner index, an index of thermal continentality, showed lower values than expected for certain particular types of vegetation. Parameters relating to the water balance turned out to be very discriminative for separating vegetation types according to the season or the month when water begins to be scarce. Thus, water availability in soils is a limiting factor for the development of vegetation in spring or autumn as well as in summer. As expected, precipitation and temperature discriminated the altitudinal levels of vegetation. Finally, these index limits only worked in the territories where they were formulated, or in nearby areas.
The following values have no corresponding Zotero field: accession-num: 15997399
Keywords: climate; climatic indices; Mediterranean vegetation; multivariate analysis; phytoclimatology; Plants; Plants: classification; Principal component analysis; Seasons; Spain; Vegetation distribution; Weather

Using Vascular Plants as a Surrogate Taxon to Maximize Fungal Species Richness in Reserve Design - Chiarucci, Alessandro; D'AURIA, FRANCESCA; de Dominicis, Vincenzo; LAGANÀ, ANGELA; PERINI, CLAUDIA; SALERNI, ELENA (Conservation Biology, 2005)
Abstract: Fungi are a hyperdiverse taxonomic group that may be disappearing at a very high rate. Identifying fungal species is difficult in the field, and the use of highly specialized taxonomists is required. Data and expertise on vascular plants are, on the other hand, much more common and easy to find. We tested the potential of using vascular plants as surrogates to select reserve sites that maximize the pooled number of fungal species. We used data from 25 forest plots in Tuscany, Italy, that were sampled for woody plants, all other plants, and fungi. Species richness of woody plants and all other plants did not correlate with species richness of fungi. The gradients in species composition were similar among the three considered groups, as indicated by a detrended correspondence analysis ordination and species complementarity between pairs of plots. Fungal communities of the 25 plots had a lower β diversity than plant communities, and there were no pairs of totally complementary sites. Site prioritization for conservation was obtained through integer linear programming to find for any given number of sites those combinations containing the maximum pooled species richness of woody plants or all plants. The combinations of sites obtained by optimizing vascular plant species did not maximize the pooled species richness of fungi, whereas those obtained by maximizing woody plant species provided better results for sets of four to eight plots, but not for all the possible combinations. These results indicated that, in general, vascular plants cannot be used to maximize fungal species richness.
The following values have no corresponding Zotero field: publisher: Blackwell Science Inc
Keywords: fungi; species richness (voyant)

USO DE CONTENEDOR PROFUNDO EN EL CULTIVO DE QUERCINEAS. EFECTOS SOBRE EL CRECIMIENTO Y DISTRIBUCIÓN DE BIOMASA. - CHIRINO MIRANDA, E.; VILAGROSA CARMONA, A.; Fernández Martínez, R.; VALLEJO CALZADA, R. (IV Congreso Forestal Español, 2005)
En especies con una importante raíz pivotante, la utilización de envases profundos favorece un mayor desarrollo de la raíz principal, lo que puede resultar ventajoso en ambientes de fuertes limitaciones hídricas. El objetivo del presente trabajo fue evaluar los efectos de la utilización de un contenedor profundo sobre el crecimiento, distribución de biomasa y adaptación al campo de tres especies del género Quercus (Quercus coccifera, Quercus ilex y Quercus suber). Estas especies se cultivaron en vivero en envases de paperpot de diámetro 5 cm, con profundidad de 16 y 24 cm en Q. coccifera y de 18 y 30 cm en Q. ilex y Q. suber. Tanto en vivero como en campo, no se observó un patrón común en crecimiento y distribución de biomasa entre las especies. Los brinzales cultivados en envases profundos desarrollaron una raíz principal más larga y tendieron a presentar mayor biomasa de raíces colonizando el hoyo de plantación en las profundidades de 30 a 60 cm; lo que puede favorecer el acceso a la humedad de los horizontes más profundos del suelo
The following values have no corresponding Zotero field: periodical: IV Congreso Forestal Español pub-location: Zaragoza
Keywords: biomasa; envase forestal; raíz pivotante; sistema radical

Utility of ITS sequence data for phylogenetic reconstruction of Italian Quercus spp. - BELLAROSA, Rosanna; Simeone, Marco C.; Papini, Alessio; Schirone, Bartolomeo (Molecular phylogenetics and evolution, 2005)
Nuclear ribosomal DNA sequences encoding the 5.8S RNA and the flanking internal transcribed spacers (ITS1 and ITS2) were used to test the phylogenetic relationships within 12 Italian Quercus taxa (Fagaceae). Hypotheses of sequence orthology are tested by detailed inspection of some basic features of oak ITS sequences (i.e., general patterns of conserved domains, thermodynamic stability and predicted conformation of the secondary structure of transcripts) that also allowed more accurate sequence alignment. Analysis of ITS variation supported three monophyletic groups, corresponding to subg. Cerris, Schlerophyllodrys (=Ilex group sensu Nixon) and Quercus, as proposed by Schwarz [Feddes Rep., Sonderbeih. D, 1-200]. A derivation of the "Cerris group" from the "Ilex group" is suggested, with Q. cerris sister to the rest of the "Cerris group." Quercus pubescens was found to be sister to the rest of the "Quercus group." The status of hybrispecies of Q. crenata (Q. cerrisxQ. suber) and Q. morisii (Q. ilexxQ. suber) was evaluated and discussed. Finally, the phylogenetic position of the Italian species in a broader context of the genus is presented. The utility of the ITS marker to assess the molecular systematics of oaks is therefore confirmed. The importance of Italy as a region with a high degree of diversity at the population and genetic level is discussed.
The following values have no corresponding Zotero field: accession-num: 15619447
Keywords: ITS sequences; phylogeny; Quercus; Secondary structures

Vegetation dynamics in north-western Mediterranean regions: Instability of the Mediterranean bioclimate - De Beaulieu, J.-L.; Miras, Y.; Andrieu-Ponel, V.; Guiter, F. (Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2005)
Abstract Pollen and plant macrofossil records from a selection of sites in Spain, France and Italy are used to explore the origin and the development of the Mediterranean vegetation. The role of evergreen and summergreen taxa is discussed. The expansion of sclerophyllous trees during the Pleistocene interglacials is well correlated with the orbital forcing. During the Holocene, the large number of data illustrates latitudinal and longitudinal differences in vegetation dynamics. Multidisciplinary studies identify short terms climatic fluctuations. The debate is still open between those who attribute an increase of sclerophyllous forests during the late Holocene to a trend toward aridity and those who consider this dynamic as human-induced.
doi: 10.1080/11263500500197858doi: 10.1080/11263500500197858The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: human impact; Mediterranean ecosystems; palaeoclimates; palynology; review

Advantages and disadvantages of phytolith analysis for the reconstruction of Mediterranean vegetation: an assessment based on modern phytolith, pollen and botanical data (Luberon, France) - Bremond, Laurent; Alexandre, Anne; Véla, Errol; Guiot, Joël (Review of Palaeobotany and Palynology, 2004)
We present here the results of a first study comparing modern soil phytolith assemblages with pollen and botanical data at a North Mediterranean site. This work has shown the following limitations and advantages of phytolith analysis for the reconstruction of Mediterranean vegetation: (1) Phytoliths are produced in sufficient quantities for analysis and are well preserved in limestone environments, widespread in the Mediterranean area. (2) Young stands of Quercus ilex and Quercus coccifera, widely distributed in the Mediterranean area do not produce characteristic phytolith types in sufficient quantities to allow the calculation of a reliable index of tree cover density. (3) Pine forests, dominated by Pinus halepensis and Pinus sylvestris, are not recorded in the studied phytolith assemblages. (4) Grassland and shrubland assemblages can be distinguished through their associated phytolith assemblages, in particular by the proportion of crenate phytoliths produced in the short cells of the grass epidermis. (5) The different vegetation groups on the massif cannot be distinguished by pollen analysis. Further studies, comparing modern phytolith assemblages and quantitative vegetation data, should be carried out on forest plots that have been established for several centuries to further assess the role of phytolith analysis in vegetation reconstructions in the Mediterranean region.
Keywords: Mediterranean; modern; paleovegetation; phytolith; pollen

Analysis of rainfall trends and dry periods on a pluviometric gradient representative of Mediterranean climate in the Duero Basin, Spain - Ceballos, Antonio; Martı́nez-Fernández, José; Luengo-Ugidos, Miguel Ángel (Journal of Arid Environments, 2004)
The present work studies the trends in rainfall and the behaviour of dry spells along a pluviometric gradient representative of the conditions of the Mediterranean region. The region is characterized by a marked water deﬁcit in the summer, a pronounced irregularity in its rainfall regime, and a noteworthy frequency of dry spells or periods without appreciable rainfall. The results obtained conﬁrm the general previsions of the IPCC, with a predominance of dry years over wet ones and a negative rainfall trend in the central sector. An increase in intra-annual variability in rainfall, and a very pronounced occurrence of dry periods independent of the total annual rainfall, are also seen. These circumstances will potentially increase the vulnerability of several Mediterranean ecosystems located along the gradient that are currently subject to considerable pressure from human activities; this will increase the environmental problems of these zones (agro-forestry–grazing productivity, soil degradation, recharge of aquifers, forest ﬁres, runoff models, biological diversity and composition, etc.).
Keywords: dry spells; duero basin; Mediterranean ecosystems; rainfall gradient; rainfall variability

Analysis of serpentinophytes from north-east of Portugal for trace metal accumulation--relevance to the management of mine environment. - Freitas, H.; Prasad, M. N. V.; Pratas, J. (Chemosphere, 2004)
In north-east of Portugal, the serpentinized area is about 8000 ha with a characteristic geology and flora. The serpentine plant community and respective soils were analyzed to examine the trace metal budget in different tissues of the plants exhibiting resistance to trace metals. One hundred and thirty five plant species belonging to 39 families and respective soils have been analyzed for total Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Substantial amounts of Ni, Cr, Co and Mn were detected in plant tissues which are listed below: NI: Alyssum serpyllifolium (38105); Bromus hordeaceus (1467); Linaria spartea (492); Plantago radicata (140); Lavandula stoechas (118) and Cistus salvifolius (114); CR: L. spartea (706.7); Ulmus procera (173.4); A. serpyllifolium (129.3); Cistus ladanifer (40.8); L. stoechas (29.5); P. radicata (27.81); Setariopsis verticillata (25.7); Plantago lanceolata (24); Digitalis purpurea (23.4); Logfia minima (23.1); Arenaria querioides (23); Hieracium peleteranum (22.7); Arenaria montana (14.5); CO: A. serpyllifolium (145.1); L. spartea (63.2); P. radicata (10.4); H. peleteranum (7.3); Lepidium heterophyllum (6.9); A. querioides (6.6); C. salvifolius (6.5); C. ladanifer (6.3); L. stoechas (6.1); Anthyllis lotoides (6.1); L. minima (6.1); Euphorbia falcata (5.7) and B. hordeaceus (5.6); MN: A. serpyllifolium (830); L. spartea (339); L. stoechas (187.1); L. minima (182.7); Castanea sativa (125); Spergula pentandra (124); P. radicata (119); Cytisus striatus (115.4); Quercus pyrenaica (110); Teucrium scorodonia (109.4); Fraxinus vulgaris (109); Anthyllis sampaiana (108); Quercus ilex (108). The significance of serpentine flora, need for conservation of these fragile and environmentally invaluable plant resources for possible use for in situ remediation of metalliferous substrates are presented in this paper.
The following values have no corresponding Zotero field: accession-num: 14675842
Keywords: Environmental significance; Metal accumulators; Phytodiversity; Remediation; Serpentinophytes

Annual dynamics of phosphatase activities in an evergreen oak litter: influence of biotic and abiotic factors - Criquet, S.; Ferré, E.; Farnet, A. M.; Le petit, J. (Soil Biology and Biochemistry, 2004)
As part of a study of the processes involved in litter biodegradation, we considered the variations over 1 year of the phosphatase activities in sclerophyllous evergreen oak litter (Quercus ilex L.). Evergreen oak is representative of tree species in the forests of the French Mediterranean area. Acid (E.C. 3.1.3.2.) and alkaline (E.C. 3.1.3.1.) phosphatases, were measured over 13 months in the forest litter, along with several biotic and abiotic variables, potentially involved in the regulation of these enzymes. These comprised moisture, temperature, pH, water-extractable inorganic P (PI ), fungi, culturable heterotrophic bacteria and protein concentrations. Moisture considerably affected the production of proteins and acid phosphatases, probably formed by litter microorganisms. This result corroborated the study of Criquet et al. [Soil Biology and Biochemistry 34 (2002) 1111] which indicated that rainfall was the most important factor regulating the production and the activity of numerous enzymes in sclerophyllous forest litter. However, it appeared that moisture cannot alone predict all of the variations in phosphatase activities and the mineralisation rate of organic P (PO). Indeed, principal component analyses (PCA) and multiple regressions showed that temperature and bacterial communities were also implicated in phosphatase dynamics and PO mineralisation. Acid phosphatases were negatively correlated with the temperature, whilst alkaline phosphatases were positively correlated with this variable. The signiﬁcant correlation obtained between bacteria and PI concentrations, and the lack of correlation between bacteria and both acid and alkaline phosphomonoesterases, suggest that other important phosphatase types, such as phosphodiesterases, must be strongly implicated in PO mineralisation of the litter and in the regulation of P microbial metabolism.
Keywords: biodegradation; phosphatases; phosphate; phosphomonoesterases; phosphorus transformations; Quercus ilex

Bacillus spp. and Pisolithus tinctorius effects on Quercus ilex ssp. ballota: a study on tree growth, rhizosphere community structure and mycorrhizal infection - Domenech, Jezabel; Ramos-Solano, Beatriz; Probanza, Agustin; Lucas-Garcı́a, José Antonio; Colón, Juan José; Gutiérrez-Mañero, Francisco Javier (Forest Ecology and Management, 2004)
A local species of oak (Quercus ilex ssp. ballota) was inoculated or co-inoculated with the ectomycorrhizal fungus Pisolithus tinctorius and two plant growth promoting rhizobacteria (PGPR) of the genus Bacillus (Bacillus licheniformis CECT 5106 and Bacillus pumilus CECT 5105). Effects of inoculation on growth, on N acquisition by the plant roots, changes in rhizosphere microbial communities and the degree of mycorrhization were evaluated. Only B. licheniformis promoted the growth of Q. ilex seedlings while co-inoculation of either bacterial strain with P. tinctorius had a negative effect on plant growth. Furthermore, B. licheniformis inhibited fungal growth as revealed by ergosterol/chitin analysis. As shown by phospholipid fatty acid proﬁles, the inoculation caused a slight alteration in the microbial community structure of the rhizosphere, both in the total community and the culturable populations.
Keywords: ballota; microbial community structure; mycorrhiza; PGPR; quercus ilex ssp

Biennial acorn maturation and its relationship with flowering phenology in Iberian populations of Quercus suber - Díaz-Fernández, Pedro M.; Climent, José; Gil, Luis (Trees, 2004)
Since the XIX century, there is a controversy about the existence of biennial maturation of the acorns in Quercus suber L. While some authors recognised biennial cycles as an adaptation to habitats with short vegetative periods, other authors discarded the biennial pattern. Successive flowering events from spring to autumn and annual acorn ripening are proposed as an explanation of the multiple acorn crops typical of Iberian forests. To clarify this discussion, the presence of annual and biennial acorns was assessed in seven cork oak stands, covering a wide range of environmental conditions. In each stand, 100 individuals were sampled once in spring and once in autumn. Biennial acorns were observed with variable frequencies in all populations. There was a significant and positive relationship between latitude and the percentage of trees with biennial acorns within northern and central populations. On the contrary, this trend was not significant among southern populations. The hypothesis that the presence of biennial acorns in Quercus suber is related to individual female flowering phenology was confirmed in four populations located in the southwestern Iberian Peninsula. Unregarding local differences in the distribution of phenological stages anticipated trees bore significantly less biennial acorns than delayed individuals of the same stand. This result is coherent with the idea that the length of the vegetative period plays a crucial role in the frequency of annual and biennial acorn ripening patterns. The relationship between annual and biennial ripening cycles and the multiple acorn crops is discussed
Keywords: Cork oak; iberian peninsula; Phenology; quiescent flowers; ripening cycle

Brotación de encinas (Quercus ilex subsp. ballota) con edades elevadas. Experiencias en el monte de Riofrío (Segovia) - SERRADA, R.; BRAVO, J. A.; ROIG, S. (Invest. Agrar.: Sist. Recur. For. Fuera de Serie, 2004)
Results from an experiment with the objective of studying the sprouting capability —shoots of stump or root— on aged holm-oak trees are shown in this paper. Site of study is located in Riofrío forest, at 960 m a.s.l. at north facing slope of Guadarrama range (Central mountain range), on deep siliceous soils. After an ecological and dasonomic inventory 24 aged trees were fellen; dbh of fellen trees vary from 22.3 to 73.2 cm and age was estimated to be between 70 and 251 years. Contingence tables and logistic regression were used to test the dependence relationship among trees characteristics and the intensity of subsequent sprouting. One period growth after felling, 13 trees (62%) among the live ones (21) that had been felled present some shoots; after three growth periods, the same portion raised to 81% (17). We found only shoots of stump in 65% of the trees that had sprouted; 12% of trees that have only shoots of root and 23% of the trees with both types of shoots. Neither shoot production nor shoot type —stump or root— seems to be influenced by age.
Keywords: coppice; old holm-oak; Regeneration; shoot of root; shoot of stump; sprouting capability; viability

Carbon and nitrogen winter storage and remobilisation during seasonal flush growth in two-year-old cork oak (Quercus suber L.) saplings - Cerasoli, Sofia; Maillard, Pascale; Scartazza, Andrea; Brugnoli, Enrico; Chaves, Maria Manuela; Pereira, João Santos; Erasolia, Sofia C.; Aillardc, Pascale M.; Cartazzad, Andrea S.; Rugnolid, Enrico B.; Havesa, Maria Manuela C.; Ereiraa, João Santos P. (Ann. For. Sci., 2004)
A dual long-term 13C and 15N labeling was used to assess the contribution of winter assimilated carbon (C) and nitrogen (N) for the spring growth flush of two-year-old cork oak plants. Changes in concentrations and partitioning of winter assimilated C and N, total C and N, and total-non-structural carbohydrates were followed from January to August in the various plant parts (first year and second year leaves, stem, branches, coarse and fine roots). No loss of winter C and N was observed with time suggesting that winter assimilates are retained within the plant and contribute to storage. A strong mobilisation of C and N was demonstrated from first year leaves and fine roots during the spring growth flush. Leaves from the second year and, to lesser extent, branches acted as sinks for winter C and N. At the beginning of the new leaf growth, a significant decrease in starch concentration occurred in first year leaves. In August, before leaf fall we observed also a mobilisation from first year to second year leaves, of N assimilated after labeling. We conclude that under these experimental conditions, both winter and current C and N were used for the spring growth flush of the cork oak plants. The foliage grown during the previous year was a source of winter and recently assimilated N and a source of C from recent assimilates for the new growth in the spring.
Keywords: 13C labeling; 15N labeling; carbohydrates; Quercus suber; remobilisation

Change in plant spatial patterns and diversity along the successional gradient of Mediterranean grazing ecosystems - Alados, Concepción L.; ElAich, Ahmed; Papanastasis, Vasilios P.; Ozbek, Huseyin; Navarro, Teresa; Freitas, Helena; Vrahnakis, Mihalis; Larrosi, Driss; Cabezudo, Baltasar (Ecological Modelling, 2004)
In this study, we analyze the complexity of plant spatial patterns and diversity along a successional gradient resulting from grazing disturbance in four characteristic ecosystems of the Mediterranean region. Grazing disturbance include not only defoliation by animals, but also associated disturbances as animal trampling, soil compaction, and mineralization by deposition of urine and feces. The results show that woodland and dense matorral are more resistant to species loss than middle dense and scattered matorral, or grassland. Information fractal dimension declined as we moved from a dense to a discontinuous matorral, increasing as we moved to a more scattered matorral and a grassland. In all studied cases, the characteristic species of the natural vegetation declined in frequency and organization with grazing disturbance. Heliophyllous species and others with postrate or rosette twigs increased with grazing pressure, particularly in dense matorral. In the more degraded ecosystem, only species with well-adapted traits, e.g., buried buds or unpalatable qualities showed a clear increase with grazing. Indeed, the homogeneity of species distribution within the plant community declined monotonically with grazing impact. Conversely, the spatial organization of the characteristic plants of each community increased in the better-preserved areas, being also related to the sensitivity of the species to grazing impact. The degree of autocorrelation of plant spatial distribution at the species level and the information fractal dimension at the community level allow us to quantify the degree of degradation of natural communities and to determine the sensitivity of key species to disturbance.
Keywords: fractal analysis; grazing systems; spatial patterns

Changes in pectins and MAPKs related to cell development during early microspore embryogenesis in Quercus suber L. - Ramírez, Carmen; Testillano, Pilar S.; Pintos, Beatriz; Moreno-Risueño, Miguel a; Bueno, María a; Risueño, María C. (European journal of cell biology, 2004)
The occurrence and significance of changes in cell wall components and signalling molecules has been investigated during early microspore embryogenesis in cork oak (Quercus suber L.) in relation to cell proliferation and cell differentiation. Microspore embryogenesis has been induced in in vitro anther cultures of Q. suber by the application of a stress treatment of 33 degrees C. After the treatment, microspores at the responsive developmental stage of vacuolate microspore switched towards proliferation and the embryogenesis pathway to further produce haploid plantlets. Ultrastructural and immunocytochemical analysis revealed changes in cell organisation after induction at different developmental stages, the cellular features displayed being in relation to the activation of proliferative activity and the beginning of differentiation in young and late proembryos. Immunogold labelling with JIM5 and JIM7 antibodies showed a different presence of pectin and level of its esterification in cell walls at different developmental stages. Non-esterified pectins were found in higher proportions in cells of late proembryos, suggesting that pectin de-esterification could be related to the beginning of differentiation. The presence and subcellular distribution of Erk 1/2 MAPK homologues have been investigated by immunoblotting, immunofluorescence and immunogold labelling. The results showed an increase in the expression of these proteins with a high presence in the nucleus, during early microspore proembryos development. The reported changes during early microspore embryogenesis are modulated in relation to proliferation and differentiation events. These findings provided new evidences for a role of MAPK signalling pathways in early microspore embryogenesis, specifically in proliferation, and would confer information for the cell fate and the direction of the cell development.
The following values have no corresponding Zotero field: accession-num: 15346811
Keywords: Cell Differentiation; Cell Differentiation: physiology; Electron; MAPKs; Microscopy; microspore embryogenesis; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 1: metabolism; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase 3: metabolism; Mitogen-Activated Protein Kinases; Mitogen-Activated Protein Kinases: metabolism; Pectins; Pectins: metabolism; Proliferation; Quercus; Quercus: embryology; Quercus: enzymology; Quercus: metabolism; Seeds; Seeds: cytology; Seeds: ultrastructure

Climatic factors and establishment of Quercus ilex-communities in Trieste Province (NE Italy) - Codogno, M.; Furlanetto, A. (Annali di Botanica, 2004)
In the coastal area called "Cernizza" (near Duino. ca 15 km NW from Trieste), at an altitude between 0 and 40 m. is located a wood vegetation complex characterized by Quercus ilex and Carpinus orientalis. The bedrocks of this site is carbonatic. This wood vegetation does not occur in other sites or the Trieste province, where deciduous oak woods (Q. pubescells, Q. petraea s.1.) are dominant both on arenaceus and on carbonatic rocks. Other Quercus ilex communities are occurring only as scrubs on the calcareous coastal cliffs characterized by primitive lithosoils. In order to detect if this wood community might be an expression of the c1imate dominating this particular zone, some Duino's c1imatic data, relative lo a record period of 9 years. have been compared with the Trieste's ones. The analysed parameters were the following: air temperature. rainfall, evaporation. wind speed and relative humidity. From the comparison of these paramenters it emerged that the Duino's climate is more humid than the Trieste's one. Only in springtime Duino is less rainy than Trieste according lo the analysis of the monthly mean values of precipitation. From the ecophysiological point of view, a study of the seasonal changes of the root hydraulic conductance in some forest trees (Nardini el al .. 1998) has pointed out the superiority of Quercus ilex compared to Quercus pubescens, as regards the competitive ability of the seedlings during the spring. For this reason, the smaller spring rainfall could explain the occurrence of Quercus ilex stands not only in the neighbourhood of Duino but also at the beginning of the large valleys characterized by S•N direction in the South Eastern Alps.
Keywords: climate; Holm oak; plant ecology; Quercus ilex; Trieste province; Vegetation

Common cranes Grus grus and habitat management in holm oak dehesas of Spain - Aviles, J. M. (BIODIVERSITY AND CONSERVATION, 2004)
Changes in agricultural policies have favored tree clearing and removal of shrubs to favor intensive farming in the holm oak Quercus ilex dehesas of Iberia. The effect of these changes for bird species wintering in this agricultural landscape has been rarely analyzed. Here the effects are studied of farming changes in traditional holm oak dehesas on population size, social structure and time budget of common cranes Grus grus in eight traditional wintering sites in Spain. The role of acorn availability, the principal winter food of the species, in relation to management is also assessed. The number of cranes in each wintering area was not related to degree of agricultural intensification, nor to the availability of acorns. However, crane flock size decreased, and the relative occurrence of isolated family groups increased in less intensively transformed wintering areas characterized by the predominance of fallow lands. The age composition of crane flocks varied with acorn availability since more juveniles were reported in areas with relatively lower acorn availability. Time budget was also related to acorn availability, since cranes spent relatively more time preening in those wintering areas with higher availability of acorns. Globally evidence suggests the need to maintain the fallow land (posios) to sustain the wintering populations of cranes in Iberia, since this agro-grazing system maintains most of the juvenile cranes using the western migratory route.
The following values have no corresponding Zotero field: pub-location: VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS publisher: KLUWER ACADEMIC PUBL
Keywords: acorns; agricultural policies; holm oak dehesas

Congruency analysis of species ranking based on leaf traits: which traits are the more reliable? - Roche, Philip; Díaz-Burlinson, Natalia; Gachet, Sophie (Plant Ecology formerly `Vegetatio', 2004)
Nine leaf traits area, fresh weight, dry weight, volume, density, thickness, speciﬁc leaf area SLA, dry matter content LDMC, leaf nitrogen content LNC from ten plant species at eight sites in southern mediterranean France were investigated in order to assess their variability along a climatic gradient and their ranking congruency power. After examination of trait correlation patterns, we reduced the nine initial leaf traits to four traits, representative of three correlation groups: allometric traits dry weight, functional traits SLA and dry matter percentage and Leaf Thickness. We analysed the variability of these four leaf traits at species and site level. We observed that between species variation between 64.5 for SLA and 91% for LDMC is higher than within species variation. Allowing a good congruency of species ranking assessed by spearman rank correlation and a good reallocation of individuals to species by discriminant analysis. A site level variability between 0.7% for Dry weight and 6.9% for SLA was identiﬁed and environmental parameters altitude, temperature, precipitation, nitrogen, pH were considered as probable control factors. We found signiﬁcant correlation between SLA, LDMC and the average minimum temperature respectively r0.87 and r-0,9 and no correlation for the other traits or environmental parameters. Furthermore, we conclude that two leaf traits appear to be central in describing species: speciﬁc leaf area SLA, percentage of dry matter LDMC. While, SLA and LDMC are strongly correlated, LDMC appears to be less variable than SLA. According to our results the Dry Matter Content or its reversal Leaf Water Content appears the best leaf trait to be quantiﬁed for plant functional screening. Leaf thickness appeared to be rather uncorrelated with other leaf traits and show no environmental contingency; its variability could not have been explained in this study. Further studies should focus on this trait.
Keywords: dry matter content; France; Mediterranean; sla

Consequences of dehesa land use on nutritional status of vegetation in Central-Western Spain - Obrador-Olán, J. J. (…systems. Advances in …, 2004)
A dehesa is a silvoarable system, which results in structure and species simplification of Mediterranean forests. Activities like livestock, forestry, agriculture and, recently, hunting are carried out in these places, in which three main structures are found: trees with native grasses (G), trees with crops (C) and trees with woody understorey (M). In order to find out the effect of dehesa land use on nutritional status, we have measured the nutrient content (N and P) of the vegetation (holm-oak and crop) in three farms located in Central Western Spain, considering in each one the three aforementioned dehesa types. Additionally, the effect of the tree on soil fertility was studied in order to map soil resources around the oak-trees, which will be useful to model the tree-understorey interactions and dehesa functioning. Soil samples (first 20-cm depth) were taken at different distances from the tree (from 2 up to 20 m) in three trees per plot (9 plots: 3 farms x 3 land uses). In all samples, pH, soil organic matter (SOM), cationic exchange capacity (CEC), total N and available P were determined. Foliar nutrient content of holm-oak (N and P) was measured in mature leaves of nine trees per plot. Crop samples were collected at four distances (2, 5, 10 and 15 m) of the trunk of 9 mature trees per plot (only cropped plots). Trees in C plots presented the highest values of leaf-N, which is related to fertiliser application and to organic material incorporation/mineralization. Trees in M plots showed the lowest values of leaf-N, indicating a competitive effect of the matorral. By contrast, highest values of P were found in M plots, indicating a positive interaction between trees and shrubs in P uptake. Differences between C and G plots were not significant. In soils, values of all measured parameters, except pH, diminished according to the distance from the holm-oak, which indicates a marked and positive effect of trees on soil fertility. Regarding the land use, both N and P presented significant differences, being M and C, respectively, which had the highest contents, which does not coincide with the results from leaf nutrient contents. By contrast, N and P values in cereal had a similar behaviour to those of soil, indicating the high dependence of the crop on the nutrients of the first cm of the soil.
Keywords: dehesa management intercropped systems; leaf nutrients; Soil fertility; tree-understorey interactions

Development of a stochastic dynamic model for ecological indicators’ prediction in changed Mediterranean agroecosystems of north-eastern Portugal - Santos, Mário; Cabral, João Alexandre (Ecological Indicators, 2004)
A holistic stochastic dynamic model was developed by focusing on the interactions between conceptually isolated keycomponents, such as local passerine guilds and changes in habitat conditions, in Mediterranean agroecosystems of the “Terra Quente Transmontana region” (north-eastern Portugal). The ecological integrity of the typical patchwork of this region, with respect to land use, can be partly assessed by the observation of the occurrence of passerine guilds. These important indicators and state variables are the underlying database of our model. This model aimed the prediction of the ecological changes which can be expected when olive orchards are being intensiﬁed. The model proposed was preceded by a conventional multivariate statistical procedure (stepwise multiple regression analysis) performed to discriminate the signiﬁcant relationships between guild richness and environmental variables. Since this statistical analysis is static, the dataset recorded from the ﬁeld included true gradients of habitat changes. The model parameters were estimated from the results of the stochastic treatment and from regional data regarding tendencies within the use of land. A period of 50 years was considered. The ﬁnal model provided some basis to analyse the responses of passerine guilds to the environmental scenarios that will characterize the new agroecosystems of the region. The model simulations were incorporated into a Geographical Information System (GIS) approach. The results of the simulation revealed a structural drift within the different guild richness in response to the expected gradient of habitat changes. The possible local extinction of several species within the less well-represented guilds, such as the steppe passerine species, may be associated with a predictable reduction in ecological integrity of the typical agroecosystems. Therefore, a new structure of the passerine communities indicates that future agroecosystems will diverge from the initial or actual ecological state.
Keywords: ecological integrity indicators; mediterranean agroecosystems; olive orchards; passerine functional guilds; stochastic dynamic model

Direct and indirect impacts of fire on isoprenoid emissions from Mediterranean vegetation - Alessio, G. A.; Lillis, M. De; Fanelli, M. (Functional Ecology, 2004)
1. Fire is often associated with episodes of air pollution, possibly involving the release of biogenic isoprenoids (isoprene and monoterpenes). The direct and indirect impacts of ﬁre on isoprenoid emission by plants of the Mediterranean vegetation were studied. Leaves of Arbutus unedo, Phillyrea latifolia, Cistus incanus, Cistus mospeliensis, Pistacia lentiscus, Quercus ilex, Quercus suber, Quercus pubescens, Myrtus communis and Pinus halepensis were exposed to direct ﬁre or to the ﬁre-consequent wave of elevated temperature. 2. Half the tested plant species did not emit isoprenoids and the treatments did not induce isoprenoid emission. In contrast, isoprene was emitted by intact leaves of Q. pubescens and M. communis, while monoterpenes were emitted by intact leaves of Q. ilex, Q. suber and P. halepensis. 3. The two treatments rapidly reduced isoprene emission by isoprene-emitting species and monoterpene emission by Quercus spp. This inhibition was associated with photosynthetic inhibition, and recovery was seen in Quercus spp. within days of treatment. Recovery was also associated with the recovery of photosynthesis, suggesting that emitted isoprenoids continue to be formed predominantly from photosynthetic intermediates after a ﬁre episode. 4. In Q. pubescens leaves, however, recovery from the elevated-temperature treatment caused a sustained increase of isoprene emission which was not mirrored by a similar increase in photosynthesis. Whether this represents the induction of alternative metabolic pathways or an increase of the ﬂux of photosynthetic carbon in the isoprene pathway is not known. Isoprene-emitting species in areas surrounding ﬁre may emit a substantially larger hydrocarbon ﬂux for several days after ﬁre. 5. The elevated-temperature treatment induced the emission of α-pinene from Myrtus leaves, and the ﬁre treatment stimulated the emission of several monoterpenes from Pinus needles. The emission began to decrease within minutes in Myrtus, while it increased within the ﬁrst 100 min in Pinus, where it was detectable the day after the event although the ﬂux was smaller than in prestressed needles. 6. Exposure to ﬁre and to the associated elevated temperature may induce bursts of monoterpenes from plants that regularly do not emit these compounds and temporarily increase the load of monoterpenes in the atmosphere by pine species. These emissions may contribute to photochemical reactions involved in smog and ozone formation
Keywords: isoprene; Mediterranean plant species; Monoterpenes; Ozone; photosynthesis; Stomatal conductance; ﬁre ecology

Distribution , Ecology and Population Structure of Euphorbia monchiquensis , an Endemism in Southern Portugal - Fox, Xenia; Deil, Ulrich (Silva Lusitana, 2004)
Euphorbia monchiquensis is, within the widespread and euryoecious E. paniculata- complex, an acidophilous subspecies, endemic in Southern Portugal. To evaluate the vulnerability of this taxon vis-a-vis disturbance and landuse changes, we studied the actual distribution, the population size, the ecological requirements and the coenological value of this taxon in the Serra de Monchique, a mountainous region in the Algarve Hinterland. Data sampling was between April and July 2001. The quite constant branching system of this half shrubby spurge allows to determine the age of the indivuduals from the plant architecture and therefore to study the demographic structure in a non-destructive way. 1618 individuals, clustered in 46 populations, have been registered in the Serra. 88% were in flower. Euphorbia monchiquensis is rare relative to its overall distribution. It shows a bimodal altitudinal and coenological pattern. The majority of the populations are concentrated in the most humid mid altitudes and on the luv-ward northwestern side of the Serra. A few populations occur in the dry lowlands, linked to riverine shrublets. The plant depends on a good water supply but does not need shadowing. Within its limited bioclimatic niche, the spurge has a certain capacity of recolonisation and is not extremely sensitive to disturbance. Humid forests of the Euphorbio monchiquensis-Quercetum canariensis are just one of the preferred sociological situations. The coenological spectrum includes pure cork oak forests, Castanea sativa coppices, Eucalyptus-afforestations, mantle communities (Lonicero-Rubetum, Rubo- Nerietum), Origanion virentis fringes, abandoned meadows and roadside verges. It was in this kind of secondary habitats with intermittent disturbance, that most of the juvenile plants could be stated. Only very few plantlings were found. Most of the recorded populations are well balanced in their medium age classes, others are overaged. A correlation between habitat qualities, the reproductive effort and the regeneration efficiency could not be found. Four inflorescence- -morphotypes can be distinguished. The inflorescence architecture becomes more complex with increasing age. Euphorbia monchiquensis is not an extremely endangered, but a vulnerable species. It can be threatened by the process of Eucalyptus afforestation and by the spontaneous spread of Acacia dealbata. To give a reliable answer to the extinction risk, further aspects of its life cycle, seed bank characteristics, and reproductive behaviour have to be studied.
Keywords: age-states; conservation biology; landuse; plant architecture; reproduction; serra de monchique

Diversity and fruiting patterns of ectomycorrhizal and saprobic fungi in an old-growth Mediterranean forest dominated by Quercus ilex L. - Richard, F.; Moreau, P.-A.; Selosse, M.-A.; Gardes, M. (Canadian Journal of Botany, 2004)
We collected and mapped epigeous fruitbodies of both ectomycorrhizal (ECM) and saprobic fungi in an oldgrowth Quercus ilex L. Mediterranean forest within a permanent transect of 6400 m2 over three consecutive fruiting seasons. Out of 5382 fruitbodies, a total of 234 species were found, including 166 and 68 ECM and saprobic taxa, respectively. Both communities were mainly composed of rare species. Two genera, Russula and Cortinarius, accounted for 34.4% of ECM fruitbodies and 50% of species diversity. The three most abundant ECM species were Laccaria laccata (Scop.: Fr.) Berk. & Broome, Inocybe tigrina R. Heim, and Lactarius chrysorrheus Fr. The fruiting ECM community encompassed a few Mediterranean species and numerous broad host range temperate species. We also analysed the fruiting patterns in relation to forest structure, host composition, and natural canopy gaps. The results showed (i) a significant correlation of species richness to tree density, (ii) a richness decrease as the number of vegetation layers increases, and (iii) a preferential fruiting of some species near Q. ilex or Arbutus unedo L. Another noteworthy feature was that richness and production were greatly enhanced in canopy gaps. Selective fruiting was also observed among species. These results highlight the importance of forest structure and large woody debris for fungal conservation.
doi: 10.1139/b04-128doi: 10.1139/b04-128The following values have no corresponding Zotero field: publisher: NRC Research Press
Keywords: canopy gaps; ECM community; fungal conservation; Holm oak; macromycete fruiting patterns; saprophytic fungi

Do different habitat preference survey methods produce the same conservation recommendations for lesser kestrels? - Franco, a M. a; Catry, I.; Sutherland, W. J.; Palmeirim, J. M. (Animal Conservation, 2004)
The analysis of habitat selection underlies many conservation recommendations. Different researchers use different methods, therefore there is a need to examine whether the results are consistent. This study examined habitat selection by lesser kestrels, Falco naumanni, a globally threatened species, using two methods: visual sighting data from a 35-km transect and radio-telemetry of 33 birds. Habitat use and spatial ecology were studied across all of the breeding season in a pseudo-steppe area, where traditional agro-grazing systems are still present but some areas have been transformed into pine plantations. Telemetry data indicate that, in good quality habitat, lesser kestrels prefer to forage close to the colony. Furthermore, the home ranges obtained were smaller than those for lesser kestrels using intensively managed habitats or more forested areas. Habitat availability was determined within a 4-km radius of the colony and habitat preferences were determined using compositional analysis. Both methods were found to produce similar results, but telemetry provided a larger number of signiﬁcant differences between habitats. Before the chicks hatched, lesser kestrels preferred grazed fallows, ploughed ﬁelds and cereal, while after hatching cereal stubble was the preferred habitat. In steppe habitats the protection of such foraging habitats within a 3-km radius from the colonies could be a very effective conservation measure.
Keywords: habitat selection; Lesser kestrel; spatial ecology (PG)

The effect of cork-stripping damage on diameter growth of Quercus suber L. - Costa, A.; Pereira, H.; Oliveira, A. (Forestry, 2004)
The Mediterranean cork oak (Quercus suber L.) agro-forestry system is oriented towards cork production, with cork being extracted from tree stem and branches as planks by cutting with an axe and stripping off. The effect of damage to the tree during cork stripping was studied in cork oaks, weakened by wounding, by following the diameter growth and its seasonality during a 9-year production cycle, and comparing them with healthy cork oaks. Tree wounding decreased diameter growth during the following cycle, e.g. 8.5 mm a−1 and 9.8 mm a−1 for weakened and healthy trees, respectively, mostly in the 2 years immediately following the cork stripping. The beginning of annual growth in spring and the occurrence of the highest increments in June–August were delayed by about 1 month in the weakened trees. The cork produced by weakened trees was reduced by 13 per cent in thickness, with average cork ring widths of 3.3 mm a−1 vs. 3.8 mm a−1 for healthy trees.
10.1093/forestry/77.1.110.1093/forestry/77.1.1
Keywords: Cork Production; stripping; wound responses (PG)

The effect of low temperatures on the photosynthetic apparatus of Quercus ilex subsp. ballota at its lower and upper altitudinal limits in the Iberian peninsula and during a single freezing-thawing cycle - Corcuera, L.; Morales, F.; Abadia, A.; GIL-PELEGRÍN, E. (Trees, 2004)
We investigated the response of the photosynthetic apparatus during an episode of extreme low winter temperature in Quercus ilex subsp. ballota (Desf.) Samp., a typical Mediterranean evergreen species in the Iberian peninsula. Both plants in a woodland located at high altitude (1,177 m. a.s.l.) and potted plants obtained from acorns of the same populations grown at low altitude (225 m. a.s.l.) were analyzed. Net CO2 assimilation rate was negative and there was a marked decrease in photosystem II (PSII) efficiency during winter in leaves of the woodland population (high altitude individuals). These processes were accompanied by increases in nonphotochemical quenching (NPQ) and in the de-epoxidated carotenoids within the xanthophyll cycle, mechanisms aimed to dissipate excess energy. In addition, these deepoxidated carotenoids were largely preserved during the night. There was no chlorophyll bleaching during the winter, which suggests that leaves were not experiencing photoinhibitory damage. In fact, the net photosynthetic rate and the PSII efficiency recovered in spring. These changes were not observed, or were much more reduced, in individuals located at lower altitude after a few frosts. When the response to rapid temperature changes (from 20°C to −5°C and from −5°C to 20°C) was studied, it was found that the maximum potential PSII efficiency was fairly stable, ranging from 0.70 to 0.75. The rest of the photosynthetic parameters measured, actual and intrinsic PSII efficiency, photochemical and NPQ, responded immediately to the changes in temperature and, also, the recovery after cold events was practically immediate.
Keywords: chlorophyll fluorescence; Holm oak; photochemical and non-photochemical quenching; photoprotection; photosystem ii efficiency

Effects of a nursery CO 2 enriched atmosphere on the germination and seedling morphology of two Mediterranean oaks with contrasting leaf habit - Cortés, Pilar; Espelta, J. M.; Save, Robert; Biel, C. (New Forests, 2004)
The use of an enriched CO2 atmosphere in tree nurseries has been envisaged as a promising technique to increase productivity and to obtain seedlings with a higher root/shoot ratio, an essential trait to respond to water stress in Mediterranean-type ecosystems. In that framework, we have analyzed the effects of three levels of atmospheric CO2 concentration (350, 500 and 700 ppm) on the germination rate, growth and morphology of seedlings of two Mediterranean oaks used in reforestation programs: the evergreen Quercus ilex L. and the deciduous Quercus cerrioides Wilk. et Costa. CO2 enrichment increased the germination rate of Q. cerrioides (from 70 7 to 81 3%) while it decreased that of Q. ilex (from 71 10 to 41 12%). Seedlings of both species increased approximately 60% their total biomass in response to CO2 enrichment but at two different CO2 concentrations: 500 ppm for Q. cerrioides and 700 ppm for Q. ilex. This increase in seedlings biomass was entirely due to an augmentation of root biomass. Considering germination and biomass partitioning, an enriched CO2 atmosphere might not be appropriate for growing Mediterranean evergreen oaks, such as Q. ilex, since it reduces acorn germination and the only gains in root biomass occur at a high concentration (700 ppm). On the other hand, a moderate CO2 enrichment (500 ppm) appears as a promising nursery technique to stimulate the germination, growth and root/shoot ratio of deciduous oaks, such as Q. cerrioides
Keywords: Forest restoration; Mediterranean-type ecosystems; Nursery techniques; Quercus cerrioides; Quercus ilex; Wildﬁre

Effects of partial defoliation on carbon and nitrogen partitioning and photosynthetic carbon uptake by two-year-old cork oak (Quercus suber) saplings - Cerasoli, S.; Scartazza, A.; Brugnoli, E.; Chaves, M. M.; Pereira, J. S. (Tree Physiology, 2004)
At the end of the growing season in late July, 20-month-old cork oak (Quercus suber L.) saplings were partially defoliated (63% of leaf area) to evaluate their ability to recover leaf area after defoliation. At 18 and 127 days after defoliation, changes in starch and nitrogen pools were determined in leaves and perennial organs, and variations in photosynthetic carbon uptake were investigated. To determine the role of stored nitrogen in regrowth after defoliation, plant nitrogen was labeled in the previous winter by enriching the nutrient solution with 15N. Plants recovered the lost leaf area in 127 days. Although there was remobilization of starch and nitrogen from leaves and perennial organs, the availability of resources for growth in the following spring was not decreased by defoliation. On the contrary, starch concentration in coarse roots was higher in defoliated saplings than in control saplings, presumably as a result of the higher net CO2 exchange rate in newly developed leaves compared with pre-existing leaves.
10.1093/treephys/24.1.8310.1093/treephys/24.1.83
Keywords: 15N labeling; defoliation; Nitrogen remobilization; starch

Estimation of Mediterranean forest transpiration and photosynthesis through the use of an ecosystem simulation model driven by remotely sensed data - Anselmi, Silvia; Chiesi, Marta; Giannini, Monica; Manes, Fausto; Maselli, Fabio (Global Ecology and Biogeography, 2004)
Aim This paper investigates the use of an ecosystem simulation model, FOREST-BGC, to estimate the main ecophysiological processes (transpiration and photosynthesis) of Mediterranean coastal forest areas using remotely sensed data. Location Model testing was carried out at two protected forest sites in central Italy, one of which was covered by Turkey oak (Circeo National Park) and the other by holm-oak (Castelporziano Estate). Methods At both sites, transpiration and photosynthesis measurements were collected in the field during the growing seasons over a four-year period (1999 and 2001 for the Turkey oak; 1997, 1999 and 2000 for the holm-oak). Calibration of the model was obtained through combining information derived from ground measurements and remotely sensed data. In particular, remote sensing estimates of the Leaf Area Index derived from 1 × 1-km NOAA AVHRR Normalized Difference Vegetation Index data were used to improve the adaptation of the model to local forest conditions. Results The results indicated different strategies regarding water use efficiency, ‘water spending’ for Turkey oak and ‘water saving’ for holm-oak. The water use efficiency for the holm-oak was consistently higher than that for the Turkey oak and the relationship between VPD and WUE for the holm-oak showed a higher coefficient of determination (R2 = 0.9238). Comparisons made between the field measurements of transpiration and photosynthesis and the model estimates showed that the integration procedure used for the deciduous oak forest was effective, but that there is a need for further studies regarding the sclerophyllous evergreen forest. In particular, for Turkey oak the simulations of transpiration yielded very good results, with errors lower than 0.3 mm H2O/day, while the simulation accuracy for photosynthesis was lower. In the case of holm-oak, transpiration was markedly overestimated for all days considered, while the simulations of photosynthesis were very accurate. Main conclusions Overall, the approach offers interesting operational possibilities for the monitoring of Mediterranean forest ecosystems, particularly in view of the availability of new satellite sensors with a higher spatial and temporal resolution, which have been launched in recent years.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd
Keywords: AVHRR; Ecosystem; FOREST-BGC; Mediterranean area; Modelling; photosynthesis; Quercus cerris; Quercus ilex; Transpiration; water efficiency

Estimation of plant diversity at landscape level: a methodological approach applied to three Spanish rural areas - Ortega, M. (Environmental Monitoring and Assessment, 2004)
Approaches linking biodiversity assessment with landscape structure are necessary in the framework of sustainable rural development. The present paper describes a methodology to estimate plant diversity involving landscape structure as a proportional weight associated with different plant communities found in the landscape mosaic. The area occupied by a plant community, its patch number or its spatial distribution of patches are variables that could be expressed in gamma plant diversity of a territory. The methodology applies (1) remote sensing information, to identify land cover and land use types; (2) aspect, to discriminate composition of plant communities in each land cover type; (3) multi-scale ﬁeld techniques, to asses plant diversity; (4) afﬁnity analysis of plant community composition, to validate the stratiﬁed random sampling design and (5) the additive model that partitions gamma diversity into its alpha and beta components. The method was applied to three Spanish rural areas and was able to record 150–260 species per ha. Species richness, Shannon information index and Simpson concentration index were used to measure diversity in each area. The estimation using Shannon diversity index and the product of patch number and patch interspersion as weighting of plant community diversity was found to be the most appropriate method of measuring plant diversity at the landscape level.
Keywords: landscape; Mediterranean vegetation; metrics; plant diversity; Remote sensing

Evaluation of biomass residuals in Portugal mainland - Dias, J.; Azevedo, J. L. T. (NEW AND RENEWABLE ENERGY TECHNOLOGIES FOR SUSTAINABLE DEVELOPMENT, 2004)
The increase of the share of renewable energy sources in Portugal can be met from different sources where biomass plays a main role. This paper presents an estimation of the quantity of biomass residuals from the forest, wood industry, agriculture and agro-industry. For the forest residues, three methodologies were used based on: i) Forest clear area, ii) Forest area and trees rotation and iii) Wood production. The values obtained are based on data from the wood forest in 1995 and in data from wood production, agriculture and agro-industry from 1997 to 1999. The total amount of pine and eucalyptus residues amounts to 650 - 1045 thousand tons/year in dry basis and is lower than other estimative from other authors. The differences obtained between the methods are analyzed as a function of the assumptions made and the relative merits. Additionally, the residues produced from holm oak and cork oak are estimated as 128 thousand dry ton/year. The wood industry and cork industry contributes with a residues production around 1584 thousand dry ton/year, while the total amounts of residues produced in agriculture and agro-industry are estimated as 2001 and 872 thousand dry tons/year, respectively. Considering technical and economical limitations and alternative utilization of biomass residues, the total amount available for combustion is estimated around 2628 thousand dry ton/year and it; seasonal distribution is identified.
The following values have no corresponding Zotero field: periodical: NEW AND RENEWABLE ENERGY TECHNOLOGIES FOR SUSTAINABLE DEVELOPMENT pub-location: SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS
Keywords: biomass residuals; energy utilisation; renewable energy sources

EXPERIENCIA DE REGENERACIÓN DE ENCINAR EN LA SIERRA DE HUELVA Studies on holm oak regeneration in North Sevilla mountains - Porras Tejeiro, C. J.; Brun Esquiliche, P.; Copete Gutiérrez, J.; Pérez Méndez, R. (Cuad. Soc. Esp. Cien. For Actas de la III Reunión sobre Repoblaciones Forestales, 2004)
We have described an oak regeneration research without prohibit the grazing. Three implantation types and seven protections types have been tested. Several parameters have been measured to the seven, fifteen and twenty three months since the seeding or planting
Keywords: Dehesa; Grazing; implantación; Implantation; pastoreo; protección; Protection; Quercus

Extensively reared Iberian pigs versus intensively reared white pigs for the manufacture of liver pâté. - Estévez, M.; Morcuende, D.; Ramírez, R.; Ventanas, J.; Cava, R. (Meat science, 2004)
Physico-chemical characteristics and quality traits of the raw ingredients (muscle cuadriceps femoris, liver and adipose tissue) and the pâtés made from extensively reared Iberian pigs and intensively reared white pigs, were evaluated. The differences found between muscles, livers and adipose tissues from Iberian and white pigs influenced the characteristics of the pâtés. Compared to pâtés from white pigs, pâtés from Iberian pigs had a higher content of heme iron (27.5 μg/g vs 11.5 μg/g; p<0.05) and lower content of non-heme iron (27.5 μg/g vs 33.7 μg/g; p<0.05). Pâtés from Iberian pigs exhibited a darker colour (L (∗):18.6 vs 15.9, p<0.05) with less redness (a (∗) values: 9.1 vs 11.3; p<0.05) and yellowness (b (∗) values: 13.1 vs 14.8, p<0.05). Thus, pâtés from white pigs had higher values of chroma (18.6 vs 15.9, p<0.05) and smaller values of hue (52.5 vs 55.2, p<0.05) that those from Iberian pigs' pâtés. In fatty acid composition, pâtés from white pigs had higher proportions of SFA (37.9% vs 32.8%, p<0.05) and PUFA (14.4% vs 9.6%, p<0.05) than pâtés from Iberian pigs and lower percentages of oleic (53.4% vs 43.6%, p<0.05) and total of MUFA (57.5% vs 47.6%, p<0.05). Pâtés from Iberian pigs had a lower n-6/n-3 values (13.2 vs 17.2; p<0.05).
The following values have no corresponding Zotero field: accession-num: 22061520
Keywords: Extensive; fatty acids; Iberian pigs; Instrumental colour; Iron; liver p; liver paté; White pigs

Farming practices and Roller Coracias garrulus conservation in south-west Spain - Aviles, J. M.; Parejo, D. (BIRD CONSERVATION INTERNATIONAL, 2004)
There are no previous studies supporting the link between the decline of Roller Coracias garrulus populations in the Palaearctic and agricultural intensification. We studied the effect of farming practices on Roller reproduction during 1988-1991 in south-west Spain. Nest-boxes were installed on power pylons that crossed six different man-made habitats representing the most characteristic habitats in the Mediterranean region: pasture fields with and without holm oak Quercus roffindifolia trees, cereal fields with and without holm oak trees, scrub fields and irrigated fields. Rollers nesting in nest-boxes erected in unwooded pasture field had the highest breeding success, suggesting that this is the most suitable nesting habitat of Rollers in the region. There were no significant effects of farming practices in habitat adjacent to nests on Roller laying date and clutch size. However, after controlling for laying date, current agricultural practices around nests affected chick mortality, with higher losses in irrigated fields. Breeding success and egg productivity were also affected by farming activities, with the lowest values in irrigated fields. Future conservation plans for Rollers should consider that nest-box provision might increase habitat suitability for Roller reproduction and that highly intensified agricultural practices might have deleterious effects on Roller populations.
APSAPSThe following values have no corresponding Zotero field: pub-location: 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA publisher: CAMBRIDGE UNIV PRESS
Keywords: Agricultural intensification; farming practices; Mediterranean; nest-boxes; reproduction; Roller Coracias garrulus

Frost resistance of seeds in Mediterranean oaks and the role of litter - Esteso-Martínez, Jordán; Gil-Pelegrín, Eustaquio (Ann. For. Sci., 2004)
The endogenous frost resistance of the seeds of four Mediterranean oaks (Quercus coccifera, Q. faginea, Q. ilex and Q. pyrenaica) with different leaf abscission phenology was tested. Thermal analysis and polyelectrolytes leakage methodologies were employed to establish lethal temperature thresholds. Results showed a higher frost resistance for evergreen species and lower for deciduous species in this decreasing order: Q. coccifera, Q. ilex, Q. faginea and Q. pyrenaica. The cover of leaf litter generated by deciduous species could be an isolating element which allowed seed survival under cold winter conditions to that species with a lower frost resistance. Differences in temperature above and below a leaf litter cover along a winter season were measured in a Q. faginea stand, in this sense the kind effect of leaf litter from a thermal point of view was proved.
Keywords: frost resistance; leaf litter; polyelectrolytic leakage; Quercus; thermal analysis

Genetic transformation of selected mature cork oak (Quercus suber L.) trees. - Alvarez, R.; Alonso, P.; Cortizo, M.; Celestino, C.; Hernández, I.; Toribio, M.; Ordás, R. J. (Plant cell reports, 2004)
A transformation system for selected mature cork oak (Quercus suber L.) trees using Agrobacterium tumefaciens has been established. Embryos obtained from recurrent proliferating embryogenic masses were inoculated with A. tumefaciens strains EHA105, LBA4404 or AGL1 harbouring the plasmid pBINUbiGUSint [carrying the neomycin phosphotransferase II (nptII) and beta-glucuronidase (uidA) genes]. The highest transformation efficiency (4%) was obtained when freshly isolated explants were inoculated with A. tumefaciens strain AGL1. Evidence of stable transgene integration was obtained by PCR for the nptII and uidA genes, Southern blotting and expression of the uidA gene. The transgenic embryos were germinated and successfully transferred to soil.
The following values have no corresponding Zotero field: accession-num: 15185122
Keywords: Agrobacterium; Cork oak; Fagaceae; Somatic embryogenesis; Tree genetic transformation

Geographical variation in the potential of mice to constrain an ant-seed dispersal mutualism - Fedriani, J. M.; Rey, P. J.; Garrido, J. L.; Guitián, J.; Herrera, C. M.; Medrano, M.; Sánchez-Lafuente, A. M.; Cerdá, X. (Oikos, 2004)
Pre- and post-dispersal Helleborus foetidus (Ranunculaceae) seed predation by mice Apodemus sylvaticus as well as post-dispersal seed removal by ants was studied, during two years, in six plant populations within three geographical regions (Caurel, Cazorla and Mágina) of the Iberian Peninsula. An observational approach revealed strong interregional differences in seed predation by mice during the pre-dispersal phase, with high and similar rates of predation in Cazorla and Mágina and much lower rates in Caurel. There were also significant inter-annual variations on pre-dispersal seed predation by mice, while the existing habitat-related differences (of lower magnitude) were not consistent across regions. Field experiments based on seed-offering exclosures, showed that, despite some interregional variation, post-dispersal seed removal by ants was consistently high through all spatial and temporal scales considered, with most seeds being removed within 48 h. Conversely, post-dispersal seed predation by mice was highly variable among regions, being very high in Cazorla and minimal or absent in Caurel and Mágina. Interestingly, in Cazorla, in presence of mice, the number of seeds removed was rather independent of the presence/absence of ants, while under mice exclusion, it was determined by the presence/absence of ants. Conversely, in Caurel, the number of seeds removed by each remover agent (ants or mice) was independent of the presence/absence of the other agent. Thus, though uniquely in Cazorla, mice limited the number of seeds available to ants and, therefore, in this region could potentially have interfered on the development of seed traits that enable ants to efficiently harvest them. Our results support the notion that geographical variation over the Iberian Peninsula of mice seed predation may have promoted a mosaic of well-matching and mismatching situations between H. foetidus diaspore traits and the characteristics of ant communities, which is consistent with some recent theories on the geographical structure of interactions.
The following values have no corresponding Zotero field: publisher: Munksgaard
Keywords: ant-plant mutualism (voyant); seed dispersal; seed predation

Growth of forest plants (pine and holm-oak) inoculated with rhizobacteria: relationship with microbial community structure and biological activity of its rhizosphere - Garcı́a, Jose A. Lucas; Domenech, Jezabel; Santamarı́a, Carmen; Camacho, Marı́a; Daza, Antonio; Mañero, F. Javier Gutierrez (Environmental and Experimental Botany, 2004)
Four bacterial strains showing in vitro metabolic capacities related to their plant growth-promoting action (plant growthpromoting rhizobacteria (PGPRs)) were studied in the growth of holm-oak (Quercus ilex ssp. Ballota) and pine (Pinus pinea) plants at a forest nursery before outplanting. All strains signiﬁcantly increased some of the parameters studied (stem length, neck diameter and shoot dry weight), although, neck root diameter showed the smallest increase in general. An interaction plant/bacterial strain was observed. Some strains speciﬁcally increased aerial parameters in both plant species, whereas other strains did so mainly in one plant species. Analyses of PLFAs and incorporation of thymidine and leucine suggest differences in the perturbation of microbial communities previously established and in the capacity of adaptation to the rhizosphere environment among the different strains
Keywords: colonisation; PGPR; Pinus pinea; plfas; Quercus ilex ssp. ballota; rhizosphere; thymidine leucine incorporation

Habitat quality as a predictor of spatial variation in blue tit reproductive performance: a multi-plot analysis in a heterogeneous landscape - Lambrechts, MarcelM; Caro, Samuel; Charmantier, Anne; Gross, Nicolas; Galan, Marie-Jo; Perret, Philippe; Cartan-Son, Mireille; Dias, PaulaC; Blondel, Jacques; Thomas, DonaldW (Oecologia, 2004)
Vertebrate studies have rarely investigated the influence of spatial variation in habitat richness on both short-term (breeding) and long-term (offspring recruitment) reproductive performance using simultaneously multi-patch, multi-habitat type and multi-year approaches at landscape level. Here we present results of such an approach using the influence of two oak tree (Quercus ilex, Q. humilis) species on reproductive performance in Corsican blue tits (Parus caeruleus ogliastrae) as a model system. We found that blue tits breeding in rich broadleaved deciduous patches consistently laid eggs earlier in the season, and produced larger clutches and more fledglings of higher quality, than those breeding in poor evergreen patches. Also, parents, especially males, were in better physical condition in the broad-leaved deciduous than in the evergreen patches. Surprisingly, estimates of long-term effects of reproduction, such as recruitment rates of locally born offspring, did not differ between the two habitat types. Our results suggest that short-term breeding performance and phenotypic quality of both chicks and parents do not necessarily provide reliable information about contributions to following generations at a scale larger than that of the local study plot. Differences in reproductive performance between the two oak habitat types could not be attributed to densitydependent effects, differences in levels of nest predation, or differences in age structure of the birds. We suggest that habitats that are optimal for breeding are not necessarily optimal for survival after the breeding season.
The following values have no corresponding Zotero field: publisher: Springer-Verlag
Keywords: Habitat quality; Parus caeruleus; Predation; Quercus; reproduction

Holm oak (Quercus rotundifolia Lam.) and Aleppo pine (Pinus halepensis Mill.) response to different soil preparation techniques applied to forestation in abandoned farmland - Bocio, Inmaculada; Navarro, Francisco Bruno; Ripoll, María Angeles; Jiménez, María Noelia; Simón, Estanislao De (Ann. For. Sci., 2004)
This paper evaluates the effectiveness of several soil preparation procedures in forestation establishment and development in localized farmland, within a territory in ombroclimatic transition between dry and semi-arid, located in Granada, southeastern Spain. An experiment in the forestation of Holm oak (Quercus rotundifolia Lam.) and Aleppo pine (Pinus halepensis Mill.) was set up, in which 8 different soil preparation techniques were used. The survival, total height and basal diameter of the plantation was monitored over a 5-year period (1996-2000). The statistical analysis of these parameters evidenced highly significant differences in the overall behaviour of the two sample forest species, related to changes in the prevailing environmental conditions in these territories and the type of soil preparation procedure applied. The overall results obtained for the three parameters analysed show the effectiveness of using backhoes for pit planting and linear rippering with a hydraulic structure to captures runoffs, in comparison to other preparations. Areal soil preparations, in particular, are not recommended.
Keywords: forestation; semi-arid; soil preparation

How plant functional-type, weather, seasonal drought, and soil physical properties alter water and energy fluxes of an oak–grass savanna and an annual grassland - Baldocchi, Dennis D.; Xu, Liukang; Kiang, Nancy (Agricultural and Forest Meteorology, 2004)
Savannas and open grasslands often co-exist in semi-arid regions. Questions that remain unanswered and are of interest to biometeorologists include: how do these contrasting landscapes affect the exchanges of energy on seasonal and annual time scales; and, do biophysical constraints imposed by water supply and water demand affect whether the land is occupied by open grasslands or savanna? To address these questions, and others, we examine how a number of abiotic, biotic and edaphic factors modulate water and energy ﬂux densities over an oak–grass savanna and an annual grassland that coexist in the same climate but on soils with different hydraulic properties. The net radiation balance was greater over the oak woodland than the grassland, despite the fact that both canopies received similar sums of incoming short and long wave radiation. The lower albedo and lower radiative surface temperature of the transpiring woodland caused it to intercept and retain more long and shortwave energy over the course of the year, and particularly during the summer dry period. The partitioning of available energy into sensible and latent heat exchanged over the two canopies differed markedly. The annual sum of sensible heat exchange over the woodland was 40% greater than that over the grassland (2.05 GJ m−2 per year versus 1.46 GJ m−2 per year). With regards to evaporation, the oak woodland evaporated about 380 mm of water per year and the grassland evaporated about 300 mm per year. Differences in available energy, canopy roughness, the timing of physiological functioning, water holding capacity of the soil and rooting depth of the vegetation explained the observed differences in sensible and latent heat exchange of the contrasting vegetation surfaces. The response of canopy evaporation to diminishing soil moisture was quantiﬁed by comparing normalized evaporation rates (in terms of equilibrium evaporation) with soil water potential and volumetric water content measurements. When soil moisture was ample normalized values of latent heat ﬂux density were greater for the grassland (1.1–1.2) than for the oak savanna (0.7–0.8) and independent of moisture content. Normalized rates of evaporation over the grassland declined as volumetric water content dropped below 0.15 m3 m−3 , which corresponded with a soil water potential of −1.5 MPa. The grassland senesced and quit transpiring when the volumetric water content of the soil dropped below −2.0 MPa. The oak trees, on the other hand, were able to transpire, albeit at low rates, under very dry soil conditions (soil water potentials below −4.0 MPa). The trees were able to endure such low water potentials and maintain basal levels of metabolism because ecological forcings kept the tree density and leaf area index of the woodland low, physiological factors forced the stomata to close progressively and the trees were able to tap deeper water sources (below 0.6 m) than the grasses.
Keywords: Biosphere–atmosphere interactions; ecohydrology; evaporation

Identification of Portuguese Armillaria Isolates by Classic Mating-Tests and RFLP-PCR Analysis of the ITS1 Region of Ribosomal DNA - Bragança, Helena; Tenreiro, Rogério; Santos, Natércia (Silva Lusitana, 2004)
The diagnosis of Armillaria, a genus including distinct species of highly woody plantpathogenic root-infecting fungi with worldwide distribution, is usually based on morphological characteristics and mating-tests, although the PCR-based restriction fragment length polymorphism (RFLP-PCR), specifically in nuclear rDNA spacers, have also been applied. In the present study, mating-tests and restriction analysis of Internal Transcribed Spacer 1 (ITS1) were used to identify 20 isolates of a Portuguese Armillaria collection. Although the majority of the diploid isolates (80%) could be identified in diploid-haploid pairings, the method is laborious, takes too much time (up to 2 months), and presents a high rate of inconclusive results. The ITS1 region showed to be a reliable molecular marker for A. mellea, in particular when HinfI restriction analysis is applied, since two fragments with 245 bp and 125 bp have been obtained for this most aggressive species whereas 290 bp and 70 bp were produced from isolates of the other European species. As simple molecular techniques are involved and the whole procedure can be performed in one day, A. mellea identification by ITS1 analysis is a clearly accessible and more advantageous tool to plant pathology laboratories, mainly those involved on the control and preservation of forest trees
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: Armillaria mellea; Cork oak; rDNA; RFLP-PCR; Woody plants

Increasing drought decreases phosphorus availability in an evergreen Mediterranean forest - Sardans, Jordi; Penuelas, Josep (Plant and Soil, 2004)
Mediterranean ecosystems are water-limited and frequently also nutrient-limited. We aimed to investigate the effects of increasing drought, as predicted by GCM and eco-physiological models for the next decades, on the P cycle and P plant availability in a Mediterranean forest. We conducted a ﬁeld experiment in a mature evergreen oak forest, establishing four drought-treatment plots and four control plots (150 m2 each). After three years, the runoff and rainfall exclusion reduced an overall 22% the soil moisture, and the runoff exclusion alone reduced it 10%. The reduction of 22% in soil moisture produced a decrease of 40% of the accumulated aboveground plant P content, above all because there was a smaller increase in aerial biomass. The plant leaf P content increased by 100 ± 40 mg m−2 in the control plots, whereas it decreased by 40 ± 40 mg m−2 in the drought plots. The soil Po-NaHCO3 (organic labile-P fraction) increased by 25% in consonance with the increase in litterfall, while the inorganic labile-P fraction decreased in relation to the organic labile-P fraction up to 48%, indicating a decrease in microbial activity. Thus, after just three years of slight drought, a clear trend towards an accumulation of P in the soil and towards a decrease of P in the stand biomass was observed. The P accumulation in the soil in the drought plots was mainly in forms that were not directly available to plants. These indirect effects of drought including the decrease in plant P availability, may
Keywords: climate change; Drought; Mediterranean ecosystems; mineralomasses; nutrient concentrations; nutrient cycles; phosphorus; Quercus ilex; Soil

Indicator taxa of spider (Araneae) diversity and their efficiency in conservation - Cardoso, Pedro; Silva, Israel; de Oliveira, Nuno G.; Serrano, Artur R. M. (Biological Conservation, 2004)
A considerable number of alternative approaches have been suggested during the last years to predict species richness of a given taxon, while retaining information on the identities of the observed individuals. Such information can be extremely useful for choosing conservation priority areas, either by using raw richness values or, preferentially, by considering the complementarity between potential sites. Among the most popular approaches is the use of indicator taxa. Both one single family and a group of several families are here tested in their ability to predict the number of spider (Araneae) species independently of sampling eﬀort, geographical location and type of habitat. We use data from three Portuguese protected areas as a test case. A two-family indicator group – Gnaphosidae and Theridiidae – is found to be a good surrogate of species richness, even if caution is needed regarding the comparison of sites with considerably diﬀerent sampling eﬀort or vegetation cover. No single family can be seen as a good surrogate of the totality of spiders. In addition, only a group of the two mentioned families is found to be eﬃcient and reliable either when used to rank sites according to taxa richness or for determining near-minimum sets of sites for conservation. We therefore recommend surrogacy with this indicator group as a promising approach for the prediction of spider species richness or evaluation and ranking of areas according to their conservation importance. The reached conclusions should uphold for Portugal and the entire Mediterranean region.
Keywords: Complementarity; estimation; Mediterranean; Portugal; Species richness

An interdisciplinary approach for integrating landscape management in the Common Agricultural Policy: Application to the municipality of Mertola, Southern Alentejo, Portugal - Oliveira, R.; Pinto-Correia, T. (ROLE OF BIODIVERSITY CONSERVATION IN THE TRANSITION TO RURAL SUSTAINABILITY, 2004)
This paper seeks to present the methodological approach of a case-studyat a local scale, in the south of Portugal, where the European Union Common Agricultural Policy (CAP) has significant impacts in terms of environment, socioeconomic and landscape aspects. The municipality of Mertola is located in the south-eastern part of the Alentejo Region, in a marginal area in relation to socio-economic parameters and agricultural production. As in the region as a whole, the dominant land use system is the Montado in a diversified pattern, which has in the last decades been subject. to successive significant changes, raising questions as to future landscape quality, identity and the required management. As in other European rural areas, the transformations in agriculture and the productive function resulted in changes in the landscape, which have impacts also on other functions such as conservation, environment balance, recreation, life support and preservation of cultural identity. These other functions attract each day more attention as a possible set of alternatives uses in marginal areas of Europe, such as Mertola. This actual context requires thus a landscape management based on integrated policies for the rural world, following the new perspectives of the CAP but also based on a deep knowledge of local landscape dynamics and requirements for preservation of identity. This project intends to evaluate and understand: (a) the changes that have occurred in the municipality in the last decades; and (b) how they have affected landscape pattern and also people's perception and connections to this landscape identity. The intent is to build up proposals for a more integrated and locally adapted formulation of CAP objectives and instruments. This paper will present the changes in landscape pattern and character registered in the study area for the last decades, the interdisciplinary methodology adopted, as well as the results of the first phase of the project.
The following values have no corresponding Zotero field: periodical: ROLE OF BIODIVERSITY CONSERVATION IN THE TRANSITION TO RURAL SUSTAINABILITY pub-location: NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS

Invasión del matorral por Genista hystrix en una dehesa salmantina (España) - Caro Domínguez, Francisco; Sánchez Anta, María Ángeles; Tarazona Lafarga, Teresa (Ecología Aplicada, 2004)
The invasion of Genisto hystricis-Cytisetum multiflori shrubs in a Salamancan "dehesa" (Quercus forest with low density), was studied using permanent quadrat and transect methodology. The results indicate that, of all shrub species, Genista hystrix Lge. is the predominant invading species in this sclerophyllous formation, due to its growth rate and phenomorphology. The overall invasion rate of this shrub in the "dehesa" has been calculated to be approximately 2.26 m 2 per year
Keywords: "dehesa"; Cytisus multiflorus (L'Hèr.) Sweet.; Cytisus scoparius (L.) Link; dynamics; Genista hystrix Lge.; Invasive species; Quercus rotundifolia Lam.; Salamanca; sclerophyllous; Shrubs

Isoprenoid emissions of Quercus spp. (Q. suber and Q. ilex) in mixed stands contrasting in interspecific genetic introgression - Staudt, Michael; Mir, Celine; Joffre, Richard; Rambal, Serge; Bonin, Aurelie; Landais, Damien; Lumaret, Roselyne (New Phytologist, 2004)
• Among oak species, Quercus ilex is classiﬁed as a monoterpene emitter and Q. suber is mainly known as a nonisoprenoid emitter. The extent and origin of this diversiﬁcation is unknown. • We examined intra- and interspeciﬁc emission variability in two mixed stands which differed in their level of hybridization and reciprocal genetic introgression based on variations in cytoplasmic (chloroplast DNA) and nuclear (allozyme) markers. • At both sites all trees identiﬁed as Q. ilex, or as recent descendants from Q. ilex × Q. suber hybrids, emitted monoterpenes. Of Q. suber trees (genetically introgressed or not by Q. ilex), 91% were also monoterpene emitters, and the remainder nonemitters. One tree identiﬁed as a Q. canariensis × Q. ilex hybrid emitted both isoprene and monoterpenes. Compared with Q. ilex, the standard emission rate of Q. suber was higher in summer and lower in autumn. Both species emitted the same monoterpenes, proportions of which showed signiﬁcant intra- and interspeciﬁc variability. • The results suggest that Q. suber populations in the French Mediterranean intrinsically emit monoterpenes, and that gene ﬂow between oak species contributes to diversiﬁcation of emission signatures.
Keywords: basal emission rate; chemotaxonomy; chemotypes; Evergreen oaks; genetic introgression; isoprene; Monoterpenes; VOC (volatile organic compound) emissions.

La diversitá cloroplastica delle querce italiane: evidenze di una maggiore ricchezza genetica nelle popolazioni meridionali e insulari - Fineschi, S.; Vendramin, G. G. (iForest - Biogeosciences and Forestry, 2004)
Results of the analysis of non-coding regions of the chloroplast genome in Italian population of deciduous oaks (subgenus Quercus) and holm oak (subgenus Scleropyllodris) are reported. Deciduous oak revealed the occurrence of six chloroplast haplotypes, differently distributed in the single geographic areas (northern, central, and southern Italy, and major islands). Moreover, most of the present Italian oak populations seems to derive from two major refugia, located in Sicily and in the Balkans, respectively. The most likely migration dynamics from the refugia towards the central and northern part of the peninsula are discussed. Migration pathways resulted to have been different in the various geographic areas. The presence of an endemic haplotype in Sardinia and Corsica was considered of particular interest. In Italian holm oak populations eight haplotypes were detected, six of them in Sicily. Five out of six Sicilian haplotypes resulted to be endemic. The Italian peninsula was colonized by two major haplotypes, one of them originating from Sicily. Results on deciduous oaks and holm oak in Italy highlight the important role played by the populations from the south and from the major islands in the colonization the Italian peninsula after the last ice age.
The following values have no corresponding Zotero field: pub-location: (1) CNR Istituto per la Protezione delle Piante, via Madonna del Piano, Edificio E, 50019 Sesto Fiorentino, Firenze; (2) CNR Istituto di Genetica Vegetale, sezione di Firenze, via Madonna del Piano, Edificio D, 50019 Sesto Fiorentino, Firenze publisher: SISEF - Italian Society of Silviculture and Forest Ecology
Keywords: Chloroplastic Diversity; colonization; conservation; glacial refugia; phylogeography; Quercus

Laccase and peroxidase isoenzymes during leaf litter decomposition of Quercus ilex in a Mediterranean ecosystem - Di Nardo, C.; Cinquegrana, A.; Papa, S.; Fuggi, A.; Fioretto, A. (Soil Biology and Biochemistry, 2004)
The dynamics of leaf litter decomposition of Quercus ilex (L.) were investigated over a 2 year period by determining the activities and isoenzyme distribution of laccases and peroxidases. The analysis of isoenzymes was performed by isoelectric focusing on high stability pH gradients with high resolving power. The preparation of zymograms was carried out using the leaf litter extract without previous concentration. During litter decomposition, laccase and peroxidase activities changed as well as the type and number of enzyme isoforms. The activities of both enzymes were low (%0.017 and %0.031 mmol o-tolidine oxidized hK1 gK1 d.w. for laccase and peroxidase, respectively) in ﬁrst year and increased in October–January of the second year of litter decay. The highest activities measured after 15–18 months of litter exposure (0.37G0.03 and 0.19G0.02 mmol o-tolidine oxidized hK1 gK1 d.w. for laccase and peroxidase, respectively), showed that litter chemical composition affected the growth of ligninolytic microbial community. The activation energy for laccase and peroxidase reactions also changed during decomposition: the highest values (55G6 kJ molK1 for laccase and 60G6 kJ molK1 for peroxidase) occurred in autumn–winter, even if spatial changes were evidenced. Some enzyme isoforms (pIZ5.3 and 5.5 for laccase and pIZ5.0 and 5.1 for peroxidase, respectively), contributed more than others to the overall laccase and peroxidase activity, suggesting that some ligninolytic species bloomed in particular seasons of the year, even if other species with similar functional activities colonized the litter.
Keywords: Enzyme activity; isoelectrofocusing; laccase; litter decomposition; peroxidase

Land manager attitudes toward management, regeneration, and conservation of Spanish holm oak savannas (dehesas) - Plieninger, T.; Modolell y Mainou, J.; Konold, W. (Landscape and Urban Planning, 2004)
Biological conservation in Spanish dehesas critically depends on the long-term persistence of a holm oak tree layer.Managers of private estates in Cáceres province, Spain, were surveyed about their conservation attitudes and behavior, especially as regards the widespread regeneration failure of oak stands. The aim was to define land-user perspectives on oak conservation in dehesas as basis for the design of suitable oak regeneration programs. Dehesa estates are managed diversely for a variety of goals, with lamb and beef production predominating. Small operations (‘minifundios’) had significantly higher stocking levels than large operations (‘latifundios’). Results suggest that managers strongly appreciate oaks, both for income- and non-income-related motivations like the preservation of real estate value or family tradition. Concern about threats to oak stands like lacking regeneration, oak decline, or conversion in urban areas varied in intensity, but most managers expected major changes for the future. Statistical relationships were established between oak appreciation and socio-economic variables like age, land ownership, years the operation had been owned by the family, and use of oak products. The survey revealed great confusion about existing oak conservation regulations. For long-term support to be assured, policy should orient its efforts toward conservation incentive schemes, environmental education, and technical assistance.
Keywords: Dehesa; Land-use; landowner motivations; Mediterranean; Quercus ilex; rangeland policy

Litter decomposition and faunal activity in Mediterranean forest soils: effects of N content and the moss layer - Garcia-Pausas, Jordi; Casals, Pere; Romanyà, Joan (Soil Biology and Biochemistry, 2004)
Accumulation of soil carbon is mainly controlled by the balance between litter production and litter decomposition. Usually In Mediterranean forests there are contrasting conditions in the distribution of faunal activity and the moss layer that may have different effects on litter decomposition. Decomposition and faunal activity were studied by exposing litter of contrasting quality (Pinus halepensis Mill. and Quercus ilex L.) for 3.5 yr in three Mediterranean pine forests of the eastern Iberian Peninsula. The effects of mosses on decomposition and on faunal activity were studied by exposing P. halepensis litter either on moss patches or directly on the forest ﬂoor. Faecal pellet production was used as an indication of faunal activity. Water availability or soil characteristics seem to limit faunal activities in the drier sites. Faecal pellets were not found during the ﬁrst stages of decomposition and in all sites they appeared when about a 30% of the initial litter had decomposed. Under wet conditions faecal pellet production was very high and a mass balance suggested that soil faunal activity may result in a net ﬂow of organic matter from the lower organic horizons to the surface Oi horizon. Mosses slightly increased mass loss of pine litter probably as a consequence of high potentially mineralizable nitrogen in the Oa horizon of moss patches and also, perhaps, as a consequence of the higher moisture content measured in the Oi horizon needles sampled among the mosses. In contrast, moss patches reduced faunal activity. The effect of litter quality on mass loss was not always signiﬁcant, suggesting an interaction between litter quality and site conditions. During the ﬁrst stages of decomposition there was N immobilisation in P. halepensis litter (poorer in N) and N release from Q. ilex litter (richer in N). In conclusion, in these forests soil microclimate and/or N availability appear to be more important controlling litter decomposition than the distribution of faunal activity.
Keywords: faecal pellets; litter decomposition; litter n content; Mediterranean forests; moss layer; nitrogen dynamics

MEDIÇÃO DA EVAPOTRANSPIRAÇÃO EM COBERTOS DESCONTÍNUOS: MONTADO DE SOBRO NA REGIÃO DE LISBOA Mª Isabel F. R. FERREIRA - Ferreira, Mª Isabel F. R.; Silva, Rodolfo M.; Paço, Teresa A. (7º Congresso da Água, Lisboa, 2004)
A quantificação do uso da água pelos cobertos lenhosos está em geral mal documentada. Em Portugal este aspecto não é irrelevante já que cerca de 2/3 da superfície agrícola útil corresponde a este tipo de cobertos (pomares, florestas, vinhas, vegetação natural,...). Em cobertos regados, a evapotranspiração (ET) segue genericamente a tendência da evapotranspiração de referência (ETo). Porém, em cobertos não regados, em condições de secura estival, essa relativa proporcionalidade deixa de existir. Nessas circunstâncias, e face à escassez actual de modelos adequados, a resolução da incerteza relativamente aos consumos pressupõe a medição directa da ET ou das suas componentes. Aplicou-se o método micrometeorológico das flutuações instantâneas ou correlações turbulentas (eddy covariance) num vasto montado com utilização silvo-pastoril, relativamente denso, no vale do Tejo (entre Montijo e Palmela). Para a estimativa da transpiração (T) foi usado um método térmico de medição do fluxo de seiva. Os resultados apresentados são de 2002 e 2003, para o fluxo de seiva e 2003 para a ET. As observações complementares permitiram testar a qualidade das medições dos fluxos atmosféricos. Dos resultados da medição da ET pelo método EC (Maio a Setembro de 2003), pode constatarse que, apesar das condições atmosféricas para a evaporação serem mais favoráveis no Verão que na Primavera, houve um decréscimo de ET de cerca de 4 mm/dia em Maio (50% da energia disponível), para cerca de 2 mm/dia em Junho e, finalmente, para cerca de 1 mm/dia, em início de Agosto e em fim de Setembro (15 a 20% da energia disponível).
The following values have no corresponding Zotero field: periodical: 7º Congresso da Água, Lisboa
Keywords: água; Evapotranspiração; Fluxo de seiva; Quercus suber; Tejo

Micropropagation du Chêne-liège (Quercus suber L.) par culture d'apex issus d'axes embryonnaires - El Kbiach, Mohamed L'bachir; Lamarti, Ahmed; Abdali, Abdeslam; Badoc, Alain (Acta Botanica Gallica, 2004)
Abstract To improve the in vitro germination and development of cork oak embryonic axes, several mineral media were tested; Durzan medium modified 1/2 supplemented with 400 mg/l glutamine and 3% sucrose gave the best results. The action of BA alone or combined with other growth regulators was also studied. A low concentration (0.44 ?M) was found to give an acceptable percentage of plantlets. When combined with NAA, callogenesis was observed. The transfer of cultures in conditions of low luminosity led to the formation of several axillary buds. These buds were multiplied on a solid medium supplemented with GA3 at low concentration. The buds were elongated, then rooted on a growth regulator-free medium after brief dipping in an auxinic solution. The rooted plants were potted on horticultural substrate.
doi: 10.1080/12538078.2004.10515443doi: 10.1080/12538078.2004.10515443The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: Cork oak; embryonic axis; in vitro culture; organogenesis; Quercus suber

Micropropagation of cork oak (Quercus suber L.) by apical bud culture from embryonic axes - El Kbiach, M. L.; Lamarti, A.; Abdali, A.; Badoc, A. (ACTA BOTANICA GALLICA, 2004)
To improve the in vitro germination and development of cork Oakembryonic axes, several mineral media were tested; Durzan medium modified 1/2 supplemented with 400 mg/l glutamine and 3% sucrose gave the best results. The action of BA alone or combined with other growth regulators was also studied. A low concentration (0.44 mu M) was found to give an acceptable percentage of plantlets. When combined with NAA, callogenesis was observed. The transfer of cultures in conditions of low luminosity led to the formation of several axillary buds. These buds were multiplied on a solid medium supplemented with GA(3) at low concentration. The buds were elongated, then rooted on a growth regulator-free medium after brief dipping in an auxinic solution. The rooted plants were potted on horticultural substrate.
The following values have no corresponding Zotero field: pub-location: FACULTE DE PHARMACIE, BP 83, F-59006 LILLE-CEDEX, FRANCE publisher: SOC BOTANIQUE FRANCE
Keywords: cork oak; Quercus suber; in vitro culture; embryon

Micropropagation of cork oak (Quercus suber L.) by axillary buds - El Kbiach, M. L.; Lamarti, A.; Abdali, A.; Badoc, A. (ACTA BOTANICA GALLICA, 2004)
The in vitro regeneration from cork oak axillary buds was investigated. Different macronutrient formulas supplemented with MS micronutrients, vitamins and 3% sucrose were tested on shoot multiplication and rooting phases. The WPM macronutrients improved caulogenesis and shoot multiplication. Rooting was achieved on WPM 1/2 macronutrients. Dipping the base of the shoots in an IBA concentrated solution improved the rooting phase. 92% of the rooted plants were successfully potted on horticultural substrate with a high relative humidity.
The following values have no corresponding Zotero field: pub-location: FACULTE DE PHARMACIE, BP 83, F-59006 LILLE-CEDEX, FRANCE publisher: SOC BOTANIQUE FRANCE
Keywords: browning; contaminants; Cork oak; micropropagation; phenolic compounds; Quercus suber L.; tissue culture

Modificación del microclima edáfico producido por riegos en forestaciones de zonas semiáridas - Jiménez, M. N.; Ripoll, M. A.; Navarro, F. B. (Investigación agraria. Sistemas y recursos forestales, 2004)
In this work, we analyse the effect that the irrigation carried out in different times during the summer drought produces on the edaphic microclimate over holm oak plants (Quercus rotundifolia) in abandoned agricultural soils of continental semiarid climate. The study has been done over 5 plots of 60 plants each, located in the high plateaux of Rambla Becerra (Guadix-Granada), in which it has been accomplished a continuation of the survival rate and development after the planting during two years (2001-2002). The answer of the plant to its new medium was excellent in all the irrigated plots, whereas in the witness plot (without irrigation) the survival is considerably inferior. The height of the holm oaks in those plots with any kind of irrigation is significantly superior than the ones in the witness plot, and the diameter of the holm oaks of the plots which receive continuous summer irrigation shows significant differences with respect to the rest of the plots. The bioclimatic diagrams achieved in each plot reflect relevant differences; the summer irrigation reaches to reduce the drought period and even, in the plot that receives the continuous summer irrigation, this is eradicated, thus generating a new period of vegetation activity. The humidity of the soil shows significant differences, being the plot number 8, which is continually being irrigated, the only one that keeps the humidity in depth. The hydric deficit diminishes punctually in the plots irrigated only once, whereas in the parcel n. 8 diminishes drastically with the following increase in the vegetation activity.
Keywords: agricultural; bioclimatic diagrams; humidity; microclimate; Soil

Multifunctionality in Mediterranean landscapes–past and future - Pinto-Correia, T.; Vos, Willem (The New Dimensions of the European Landscapes, 2004)
During past decades many of the traditional multifunctional Mediterranean landscapes with their typical complexes of agro-, silvo- and pastoral components changed thoroughly. Nowadays only few of them are still vital. Their complex farming systems secure at the same time a multitude of other functions than just agricultural production, such as support for recreation, amenity, cultural identity, preservation of natural resources and environmental quality. Some of these unique, old Mediterranean landscapes are discussed. They cover a broad range from near-tonature high mountain landscapes and terraced small-scale submediterranean polyculture landscapes to dry Mediterranean agro-silvo-pastoral landscapes. All these are changing, either spontaneously due to changing socio-economic and cultural conditions, or as a result of conscious policies, with the Common Agricultural Policy as a main driver. Even measures created to support specific traditional land uses and their landscapes are often not successful as they focus on only a part of the system. These policies and measures will not hold the valuable traditional systems from collapsing and subsequent vanishing. Some other policy instruments, such as those in forestry, are not meant to support them, but to transform them in favour of new monofunctionality. New strategies and instruments ought to deal with these multifunctional landscapes in a more integrated way, if some of them are to be maintained or transformed into others with similar qualities.
The following values have no corresponding Zotero field: periodical: The New Dimensions of the European Landscapes
Keywords: agri-environmental; agro-silvo-pastoral; CAP; landscape; Mediterranean; multifunctionality

Nest-site selection and nesting success of Little Owls (Athene noctua) in Mediterranean woodland and open habitats - Tome, R.; Bloise, C.; Korpimaki, E. (JOURNAL OF RAPTOR RESEARCH, 2004)
We studied nest-site selection by Little Owls (Athene noctua) in two Mediterranean habitats, a holm oak (Quercus rotundifolia) woodland (36 nests during 1997-99) and a steppe-like area (37 nests during 1997-99), in Southern Portugal, by comparing macrohabitat and microhabitat characteristics of used nests to those of randomly-selected nest sites. In the woodland area, predator presence seemed to be the main factor that influenced nest-site selection by owls. In the steppe area, a large number of alternative cavities around a nest appeared as the most important variable associated with nest-site selection. At this site, size of stones in stone piles also seemed to influence nest-site selection; owls nested in piles with larger than average stones. We also found tree girth was positively associated with nesting Success ill the woodland area. Larger trees held more complex cavities that may have improved the ability of adults and offspring in escaping from predators. Other variables, Such as distance to human habitations and the orientation of nest-site entrance might have influenced nesting success as well. Predation risk and the internal features of nest cavities were the most likely factors affecting nest-site selection and nesting success of Little Owls in Mediterranean habitats.
The following values have no corresponding Zotero field: pub-location: 14377 117TH STREET SOUTH, HASTINGS, MN 55033 USA publisher: RAPTOR RESEARCH FOUNDATION INC
Keywords: Athene noctua; habitat selection; Little Owl; Mediterranean Region; predation risk; reproductive success

Nitrogen-use efficiency: trade-offs between N productivity and mean residence time at organ, plant and population levels - SILLA, F.; Escudero, A. (Functional Ecology, 2004)
* 1Nitrogen-use efficiency (NUEN) is often decomposed into the product of N productivity (AN) and the mean residence time of N (MRTN). Theory suggests a trade-off between both components, but direct experimental evidence is still scarce. A field study with young trees of the evergreen Quercus ilex and the marcescent-evergreen Quercus faginea was carried out to test this trade-off through analysis of plant traits at organ, whole-plant and population levels. * 2Specific leaf area (SLA) was the main trait positively related to AN in Q. faginea. By contrast, greater litter production and consumption by caterpillars resulted in larger N losses and shorter MRTN in Q. faginea. Early leaf senescence in Q. faginea produced leaf litter with high N concentration that contributed significantly to N loss. Moreover, Q. ilex had higher plant survivorship. The inverse relationship between leaf longevity and SLA is probably a key component of the trade-off between N losses and plant N productivity. * 3Quercus faginea had greater N uptake from soil, linked to its longer specific root length of fine roots and greater biomass allocation to underground tissues. Smaller N losses in Q. ilex compensated for its smaller N uptake and allowed a similar N balance at whole-plant level. * 4Our results support the hypothesis of a trade-off between AN and MRTN. Quercus ilex had a long MRTN, while Q. faginea has a high AN, and vice versa. The long MRTN in Q. ilex involves not only reduced N loss through long intrinsic leaf life span, but also resistance to harsh environmental factors and defence against herbivores. This suggests that a long MRTN is a potentially successful strategy in nutrient-poor environments.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd
Keywords: Drought stress; herbivory; nitrogen loss; nitrogen uptake; plant strategies

Nursery cultivation regimes, plant functional attributes, and field performance relationships in the Mediterranean oak Quercus ilex L. - Villar-Salvador, P.; Planelles, R.; Enrı́quez, E.; Rubira, J. Peñuelas (Forest Ecology and Management, 2004)
In this study we have addressed the effect of nitrogen fertilisation and shading used during nursery growth on the functional quality of Quercus ilex L. (holm oak) seedlings and their outplanting performance in an abandoned continental Mediterranean cropland. Three N fertilisation regimes: high and low fertilisation (154 and 34 mg N per plant, respectively) and no fertilisation, combined with two shade levels (full sun and 45% shade) were studied. Fertilisation increased the shoot size, shoot to root mass ratio (S/R), root N, and both shoot and root P concentration of the plants produced in the nursery. Fertilisation also enhanced the capacity of new root formation. Neither tissue K nor root mass was affected by N fertilisation. Shading increased S/R and root K concentration but reduced both shoot and root N concentration. Two years after planting, unfertilised seedlings had higher mortality and grew signiﬁcantly less than those cultivated at both a low and a high fertilisation level. Shading during nursery growth had no inﬂuence on the outplanting performance of holm oak seedlings. Plants with a larger shoot and higher S/R had lower mortality and grew faster than those with a smaller shoot and lower S/R. Outplanting performance of holm oak seedlings was related with root N and P concentration and with RGC. No relationship was found with either shoot nutrient concentration or root mass. We conclude that high N fertilisation of holm oak seedlings in the nursery can improve their early ﬁeld establishment in the afforestation Mediterranean abandoned croplands.
Keywords: Afforestation; Holm oak; nitrogen; nursery fertilisation; root growth capacity; shading

OAK OPEN FORESTS ('' DEHESA " OR '' MONTADO ") OF QUERCUS ROTUNDIFOLIA LAM . IN THE IBERIAN PENINSULA AND THEIR PRODUCTS - Balbuena, Enrique; Doncel, Esperanza (International Oaks, 2004)
Features dehesa, the Spanish word used to name the open forests and woodlands of Quercus species in Iberian Peninsula. Sustainability and stability in terms of ecological products; Products derived from oak open forests; Availability of products in dehesa (citation)

Ozone monitoring in a Mediterranean forest using diffusive and continuous sampling - Santis, Franco; Zona, Donatella; Bellagotti, Raffaella; Vichi, Francesca; Allegrini, Ivo (Analytical and Bioanalytical Chemistry, 2004)
Ambient ozone was measured in a forest in Castelporziano (Italy) characterised by the prevailing presence of Holm-oak trees (Quercus ilex L.) from June to November 2003. Two methods for measuring ozone were used: long-term monitoring using diﬀusive samplers at three heights within the canopy, and continuous monitoring at two heights using the UV method. Results for one week mean ozone levels above and below the canopy from the diﬀusive samplers were compared to those obtained using the automatic analyser at the same levels. A good correlation between the two sampling techniques was found. Continuous monitoring showed a daily cycle with a midday maximum and a nocturnal minimum. While the forest ﬂoor consistently had the lowest ozone concentration, there were no diﬀerences during most daytime hours. The midday maximum is clearly due to downward mixing with O3 -rich air from above. The night-time ozone decay within the canopy is the result of dry deposition of O3 and most likely due to reaction with biogenically produced NO. AOT40 within and above the canopy mostly exceeded the critical levels
The following values have no corresponding Zotero field: publisher: Springer-Verlag
Keywords: Diffusive sampling; mediterranean forest; Ozone (vertical profile)

Refining vegetation simulation models: From plant functional types to bioclimatic affinity groups of plants - Laurent, J.-M.; Bar-Hen, A.; François, L.; Ghislain, M.; Cheddadi, R. (Journal of Vegetation Science, 2004)
Question: How to refine simulations based on a global vegetation model in order to apply it to regional scale? Location: Europe from 35° N to 71° N and 25° W to 70° E. Methods: Geographical ranges of European plants were georeferenced and used with monthly mean climatic data (diurnal temperature ranges, ground frost frequencies, precipitation, relative humidity, rain frequencies, amount of sunshine hours and temperature) and growing degree days to infer climatic boundaries for 320 taxa. We performed a discriminant analysis to define their potential geographic ranges. Hierarchical clustering was computed on potential ranges. Results: Clustering provided 25 Bioclimatic Affinity Groups (BAG) of plants consisting of 13 tree, seven shrub and five herb groups. These B AGs are characterized by different geographical ranges and climatic tolerances and requirements. Conclusion: The use of monthly data instead of annual values improved the prediction of potential distribution ranges and highlighted the importance of climate seasonality for defining the plant groups with accuracy. The B AGs are detailed enough to provide finer reconstructions and simulations of the vegetation at the regional scale.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: CARAIB; Discriminant analysis; Hierarchical clusteranalysis; Moisture; pollen; Seasonality; Temperature; Vegetation distribution

Relación entre composición y densidad de la cubierta vegetal leñosa y las características superficiales del suelo en Bosques Mixtos de Quercus del Sur de la Península Ibérica - Garcia, L. V.; POLO, A.; Maltez-Moro, S.; GUTIÉRREZ, E.; PÉREZ-RAMOS, I. M.; JORDÁN, A.; MARTÍNEZ-ZAVALA, L.; MARAÑON, T. (Tendencias Actuales de la Ciencia del Suelo, 2004)
We studied the relationships between different estimates of the woody canopy density; different estimates of litter release and accumulation, and different soil properties (mainly soil reaction and macronutrient level) which have been recognised as potentially relevant for plant establishment and development in mixed Quercus forest from Natural Park “do Sudoeste Alentejano e Costa Vicentina”, Portugal (with Q. suber, Q. faginea as dominant tree species) and Natural Park “Los Alcornocales”, Spain (with Q. suber and Q. canariensis). We have found 1) A highly significant, quantitative, relationship between litter accumulation and overall canopy density. These relationships can be established either by using objective (but time-consuming) measures (by sampling or using ad hoc measuring devices) or by calibrated by-eye estimates of three simultaneous observers; 2) A significant relationship between some soil properties (N, P, ammonium) and both canopy density and litter accumulation. We conclude that these relationships are interesting in two ways: 1) They may allow to establish ‘ecotransfer functions’ for these forests (i.e. estimates o predictions about surface litter accumulation or surface values for soil properties, as organic carbon, N or P contents, by using quick field estimates of canopy density or even remote sensing estimates of canopy density), after suitable calibrations. 2) Since some soil chemical properties with known ecological relevance (e.g. C, N, P contents, soil reaction) in forest regeneration may change in a close relationship with other more studied, better known, ecological factors (light, moisture, temperature), attention should be paid to separate direct (e.g. light limitation) versus indirect (soil or litter mediated) effects of woody canopy when evaluating ecological responses at the understorey, while studying forest regeneration processes.
The following values have no corresponding Zotero field: periodical: Tendencias Actuales de la Ciencia del Suelo
Keywords: acumulación de hojarasca; densidad cubierta vegetal leñosa; dosel leñoso; Quercus (voyant); suelo

The role of disturbance in the co-existence of the evergreen Quercus ilex and the deciduous Quercus cerrioides - Bonfil, Consuelo; Cortés, Pilar; Espelta, Josep Maria; Retana, Javier (Journal of Vegetation Science, 2004)
Question: Which is the response of the evergreen Quercus ilex and the deciduous Q. cerrioides to repeated disturbances? Location: central Catalonia (northeastern Spain), in the areas affected by two of the largest historically recorded wildfires in NE Spain: the Bages-Berguedà fire (24 300 ha forested area burned in July 1994), and the Solsonès fire (14 300 ha burned in 1998). Methods: Survival and growth of individuals of Quercus ilex and Q. cerrioides were evaluated in plants subjected to different fire histories and experimental disturbances (burning, cutting or clipping) applied either before or after summer. Results: Survival was high (> 99%), with both species showing a similar high resistance to disturbances. Growth after experimental disturbance was positively related to the size of the individual before the latest forest fire occurred. Fire history had a large effect on resprout growth, as the repeated incidence of disturbances lowered the capacity of individuals to grow. The type and season of experimental disturbance experienced by plants had a large effect. Individuals that experienced total above-ground loss had lower growth rates than those with partial loss. A similar pattern was observed in individuals disturbed after the summer in relation to those disturbed before summer. Conclusions: The larger growth rates recorded in Q. cerrioides across all fire histories and experimental treatments, and the higher vulnerability of Q. ilex to increased fire frequency, intensity of experimental disturbance, and disturbance season, provide evidence for the relatively high susceptibility of the latter to repeated disturbances. This view disagrees with the larger resilience of this species compared to co-existing deciduous oaks, as reported.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: Burning; clipping; fire; Growth; Mediterranean Region; Quercus; resilience; resprouting; Survival

The role of land abandonment in landscape dynamics in the SPA ‘Encinares del rı́o Alberche y Cofio, Central Spain, 1984–1999 - Romero-Calcerrada, Raúl; Perry, George L. W. (Landscape and Urban Planning, 2004)
Land use has changed dramatically over the last 30–40 years throughout the Mediterranean. Much of this change has been driven by shifts in agricultural and socio-economic policy. This paper explores landscape dynamics in the SPA ‘Encinares del r´ıo Alberche y Coﬁo’ Central Spain between 1984 and 1999 in an area of approximately 83,000 ha. Categorical land cover maps, derived from three (1984, 1991 and 1999) remotely sensed Landsat images, are analyzed using a suite of landscape pattern metrics, and a simple transition matrix model of landscape change is developed. As with other landscapes in the Mediterranean a key trend is that of the abandonment of agricultural land and its subsequent succession to scrubland and woodland. Although there were signiﬁcant composition changes in the landscape over the study period conﬁgurational changes are less evident. The transition matrix model suggests that there were differences in landscape dynamics between 1984–1991 and 1991–1999—most importantly an increase in the rate of land abandonment is evident. The model predicts a steady state landscape containing a higher abundance of scrubland and woodland, and a corresponding decline in pastureland and cropland. Finally, the underlying socio-economic and other drivers of landscape change in the Encinares del r´ıo Alberche y Coﬁo and some of the implications of recent changes are discussed in terms of increased wildﬁre risk. Sustainable management of landscapes to protect biodiversity requires the type of study described here. A necessary pre-requisite of such management activities or planning is an assessment of changes in landscape pattern and process, the social and economic pressures driving them, and their possible effects on ecosystem structure and function.
Keywords: Central Spain; Human disturbance; Land abandonment; landscape change; landscape heterogeneity; landscape metric; special protection areas (spa); transition matrix model

Soil quality and vulnerability in a Mediterranean natural ecosystem of Central Italy. - Francaviglia, R.; Gataleta, L.; Marchionni, M.; Trinchera, A.; Aromolo, R.; Benedetti, A.; Nisini, L.; Morselli, L.; Brusori, B.; Olivieri, P.; Bernardi, E. (Chemosphere, 2004)
Wet and dry atmospheric depositions and soil chemical and microbiological properties were determined in a Mediterranean natural ecosystem of Central Italy near Rome (Castelporziano Estate). The monitoring of depositions permitted us to quantify the exceedances of S and N compounds (expressed as eqH(+)ha(-1)year(-1)) over the critical loads of acidity. Critical loads, i.e. the quantity of a substance which a part of the environment can tolerate without adverse effects occurring, were determined adopting the level 0 methodology following the UN/ECE Convention on Long-range Transboundary Air Pollution. Deposition data were available for the period 1992-1997, and acidity exceedances were referred to the main vegetation types present in the area. Results showed that most part of the Estate has a medium degree of vulnerability to acidification, and the corresponding risk of acidification deriving from the exceedances of atmospheric deposition was rather low. The study of soil chemical and microbiological properties included mainly total soil organic carbon (SOC), microbial biomass-C, biomass-C/SOC, soil respiration, and metabolic quotient (qCO2). Soil organic C metabolism has been discussed on the basis of the results from eight sampling sites.
The following values have no corresponding Zotero field: accession-num: 14987944
Keywords: Acidification; Atmospheric depositions; Biological indicators; Critical loads; Soil microbial biomass; Soil organic carbon

Spatial structure and land-cover use in a low-density Mediterranean population of Eurasian badgers - Rosalino, Luís Miguel; Macdonald, David White; Santos-Reis, Margarida (Canadian Journal of Zoology, 2004)
Eurasian badgers, Meles meles (L., 1758), have an extensive geographic range throughout which their social organization varies. Their capacity for intraspecific variation can now best be understood by studying them in landscapes that differ from the lush, lowland farmland where their tendency to form large groups has been most intensively investigated. Badgers in cork oak (Quercus suber L.) woodland are thus a priority for study, as this Mediterranean landscape provides an extreme contrast to those studied elsewhere. In this habitat in Portugal, we found 0.36–0.48 badgers/km2, one of the lowest population densities recorded in Western Europe. Here, individuals used seasonally stable home ranges that averaged 4.46 km2 and that were occupied by 3–4 adults plus 3–4 cubs of the year. In this landscape, badgers selectively used cork oak woodland with understory and riparian vegetation. As predicted by the resource dispersion hypothesis, home-range size was positively correlated with food-patch dispersion. In southwestern Portugal, badgers depend upon an environmental mosaic such as olive groves and orchards and vegetable gardens for food and cork oak woodlands for shelter and protection.
doi: 10.1139/z04-130doi: 10.1139/z04-130The following values have no corresponding Zotero field: publisher: NRC Research Press
Keywords: cork oak woodland; eurasian badgers; habitat selection; resource dispersion hypothesis (PG); spatial structure

Stomatal responses to drought of mature trees and seedlings of two co-occurring Mediterranean oaks - Mediavilla, Sonia; Escudero, Alfonso (Forest Ecology and Management, 2004)
We studied stomatal responses to decreasing predawn water potential (Cpd ) and increasing leaf-to-air water vapour pressure deﬁcit (VPD) of seedlings and mature trees of two co-occurring Mediterranean oaks with contrasting leaf habits: the evergreen Quercus rotundifolia and the deciduous Quercus faginea. Our objective was to deﬁne and to compare the stomatal strategies of both speciesfordroughtresistanceandtoidentifythepossibledifferencesbetweengrowthstagesinselecteddroughtadaptationattributes. Among the mature trees, Q. rotundifolia exhibited a water-use behaviour that was more conservative than that of Q. faginea: lower maximum stomatal conductances and greater sensitivity to VPD than the deciduous species. As a result, the leaf water potential of the evergreen species never decreased along the day and along the growth season as much as in the deciduous species; this may help to guarantee longer leaf longevity by avoiding irreversible damage during the summer drought. The seedlings of the two species showed a less conservative water-use strategy in comparison with adult trees: a relatively high stomatal conductance and lower stomatal sensitivity to soil and atmospheric drought. As a consequence, leaf water potential decreased more in the seedlings along the day than in the adults. Q. rotundifolia was the species for which the most pronounced differences between growth stages were obtained. Thus, interspeciﬁc differences in response to drought disappeared in the ﬁrst stages of the life of the trees, and the seedlings of the two species showed a common strategy, probably as a response to the competition from the herbaceous layer. A low stomatal sensitivity in beneﬁt of an increase in growth would probably be a more successful strategy under the competitive conditions that seedlings experience during their establishment.
Keywords: Drought; growth stages; leaf water potential; mediterranean quercus species; Stomatal conductance; vapour pressure deficit

Three new species of Stibeutes and Gnotus (Hymenoptera: Ichneumonidae) from holm-oak and cork-oak Mediterranean forests - Bordera, Santiago; Hernández-Rodríguez, Estefanía (Insect Systematics & Evolution, 2004)
The new species Stibeutes hirsutus, S. calderonae and Gnotus klausi from Spanish holm-oak and cork-oak woods are described and illustrated. Data on their habitat and the phenology of S. hirsutus are reported. The species S. breviareolatus collected in a cork-oak forest is recorded for the first time for Spain. New keys for the Gnotus tenuipes species group and for the Spanish species of Stibeutes are provided.
Keywords: Gnotus; habitat; morphology; new species; phenology (PG); Stibeutes

Topography and forest composition affecting the variability in fire severity and post-fire regeneration occurring after a large fire in the Mediterranean basin - Broncano, M. J.; Retana, J. (INTERNATIONAL JOURNAL OF WILDLAND FIRE, 2004)
This study relates the spatial variability in tree regeneration generated by fire with topography and pre-fire vegetation composition, and analyses how the pattern of fire severities determines post-fire regeneration of the dominant tree species (Pinus halepensis and Quercus ilex) in a large fire that occurred in north-eastern Spain in summer 1994. At the fire level, the proportion of the different fire severities in the burned area was characteristic of large fires that burn with high severity. At the level of plot, the variability of fire severity in the study site depended on two topographic characteristics: elevation and aspect. Plots burned with high fire severity were distributed at higher altitude than less severely burned plots, which were mainly distributed in south- and east-facing slopes. Fire severity also increased with Q. ilex density in the stand. The mosaic of fire severities determined both plant mortality and seedling regeneration. Mortality of stems caused by fire was very high in both species, but many Q. ilex individuals resprouted after fire. Seedling regeneration of P. halepensis showed large differences among plots in the burned area, reflecting large spatial variability due to the elevation gradient, the variation in density of adult pine trees, and the spatial variability created by fire.
The following values have no corresponding Zotero field: pub-location: 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA publisher: C S I R O PUBLISHING
Keywords: mortality; post-fire regeneration; resprouting

Trace metal fluxes in bulk deposition, throughfall and stemflow at two evergreen oak stands in NE Spain subject to different exposure to the industrial environment - Avila, Anna; Rodrigo, Anselm (Atmospheric Environment, 2004)
We compare here the bulkdeposition, throughfall and stemﬂow ﬂuxes of dissolved trace metals in two holm oak (Quercus ilex L.) forests in the Montseny Mountains (NE Spain) with the aim of: (1) applying different methods to distinguish between dry deposition and canopy leaching and (2) to add to the almost non-existing deposition measurements for dissolved Cu, Pb, Mn, V, Zn, Ni and Cd in two Spanish forests differentially exposed to the urban and industrial environment. No signiﬁcant differences in mean bulkdeposition concentrations or ﬂuxes were found between sites, indicating little differential effect of the urban/industrial environment on bulkprecipitation chemistry. At both sites, throughfall and stemﬂow ﬂuxes increased relative to bulkdeposition for all elements, except for Zn and Cd. The relative contribution of leaching and dry deposition was evaluated through: (1) the seasonal variability of throughfall, (2) regressions of element ﬂuxes on water ﬂux in net throughfall, (3) washing branches and metacrylate plates, and (4) the sequential washing of branches. Results indicated that leaching was the main enrichment process for Mn. For Ni, except the sequential washings, all other evidences also pointed to leaching. For Cu, Pb, Zn, Cd and V there was ample evidence for dry deposition. The fact that Zn and Cd had negative net throughfall ﬂuxes indicated that canopy uptake was greater than deposition (wet plus dry). Net throughfall ﬂuxes pointed to higher dry deposition onto the canopies in the more exposed site, but the occurrence of uptake impeached quantiﬁcation. Therefore, dry deposition was estimated from the recovered quantities from experimental washings of foliage, taken to represent the impaction of small particles onto the canopy. The foliage-wash ﬂuxes were, for Zn, Cu and Pb, respectively, 407, 25 and 16 g ha 1 yr 1 at the sheltered site and 423, 38 and 26 g ha 1 yr 1 at the exposed site. Deposition in bulkprecipitation (wet deposition+an unknown fraction of dry deposition mostly accounted by coarse particles settling gravitationally) was lower: 222, 6.3 and 6.5 g ha 1 yr 1 for Zn, Cu and Pb, respectively, averaged for the two sites
Keywords: Dry deposition; Leaching; Mediterranean forests; surrogate surfaces; throughfall; Trace metals

USE OF THERMAL IMAGING TECHNIQUES AND XANTHOPHYLLS CONTENT FOR DETERMINATION OF STRESS IN CORK OAK (QUERCUS SUBER L.) - Tronina, L.; Grant, O. M.; Ramalho, J. C.; Chaves, M. M. (ACTA PHYSIOLOGIAE PLANTARUM, 2004)
Understanding the responses of cork oak (Quercus suber L.) to actual and predicted summer conditions is essential to determine the future sustainability of cork oak woodlands in Iberia. Thermal imaging may provide a rapid method for monitoring the extent of stress. The ecophysiology of cork trees was studied over three years. Three treatments were applied by means of rainfall capture and irrigation, with plots receiving 120%, 100%, or 80% of natural precipitation. Despite stomatal closure, detected using both thermal imaging and porometry, leaf water potential fell during the summer, most drastically during the third year of accumulative stress. The quantum efficiency (ΦPSII) and the maximum efficiency Formula of photosystem II also fell more intensely over the third summer, while non-photochemical quenching (NPQ) increased. The reduced precipitation treatment sporadically further reduced leaf water potential, stomatal conductance (gs), IG (an index of gs derived from thermal imaging), ΦPSII, and Formula, and increased leaf temperature and NPQ. It is concluded that these are very resilient trees since they were only severely affected in the third year of severe drought (the third year registering 45% less rainfall than average), and removing 20% of rainfall had a limited impact.
Key words: ASKey words: ASThe following values have no corresponding Zotero field: pub-location: TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY publisher: SPRINGER HEIDELBERG
Keywords: Quercus suber L.; Stress; thermal imaging

Vegetation dynamics of Mediterranean shrublands in former cultural landscape at Grazalema Mountains, South Spain - Gallego Fernández, Juan B.; Rosario García Mora, M.; García Novo, Francisco (Plant Ecology (formerly Vegetatio), 2004)
Plant community dynamics in Mediterranean basin ecosystems are mainly driven by an alternation of episodes of human intervention and land abandonment. As a result, a mosaic of plant communities has evolved following different stages of degradation and regeneration. Some authors has relate secondary succession to abandoned culture lands and regeneration to natural systems with abandonment of livestock or forestry exploitation. In this paper, the dynamics of shrublands in mid-mountain areas in the South of Spain after disturbance and land abandonment has been studied. The plant cover and 13 environmental variables of 137 selected sites on the Grazalema mountains was analysed to determine the vegetation pattern in relation to environmental factors and the succession types, either regenerative or secondary succession. The results show that today the Grazalema mountains have a heterogeneous vegetation pattern. Besides physical factors such as altitude or soil pH, human disturbance has modulated current vegetation patterns and dynamics. Two main types of vegetation dynamics can be distinguished in the study area. In areas affected by cutting, regeneration results in rich and dense shrub land, with resprouters as dominant species. In areas affected by recurrent wildﬁres or agriculture, secondary succession became dominant, resulting in less diverse shrubland, due to the dominance of seeders and decrease in resprouter species richness and cover.
Keywords: Human disturbance; Land abandonment; Mediterranean vegetation; Regen- erative succession; Regenerative strategies; Secondary succession

Agrarian elites and economic growth in nineteenth-century Portugal: The example of the Alentejo in the Liberal era (1850-1910) - Fonseca, Helder Adegar (Social History, 2003)
The Alentejo is a southern Portuguese region which is generally recognized for the social and economic importance of the latifúndio system and for its economic backwardness, phenomena which are usually associated with the existence of a regional elite of the traditional type. This article seeks to review this question by examining the action of the economic elite which operated in the region during the second half of the nineteenth century, when modern capitalism was just beginning to develop in Portugal and Liberal institutions were being established. How this sociologically renewed and plural elite group conducted its private business dealings is described, and investment strategies and sources of financing are examined, as well as the management of farm businesses. Three aspects are highlighted here: the varied nature of investments, although over the long term there was an increase in the acquisition of land; investment carried out at the cost of growing indebtedness to the regional banks, the modern financial institutions which the elite helped to set up; and the high degree of involvement of land-owners in the running of large estates, which were marked by a trend towards division into smaller units, moves towards productive diversification, and the drive for technical progress and the modernization of rural buildings. Examined as a whole, this scenario suggests that the new economic elite which emerged with the triumph and development of Portuguese Liberalism in the nineteenth century was not a force for conservatism in the regional economy.
doi: 10.1080/0307102032000082507doi: 10.1080/0307102032000082507The following values have no corresponding Zotero field: publisher: Routledge
Keywords: Alentejo; economic elite; land acquisition; large estates (voyant); XIX century

Assessment of nutritional status and trace element contamination of holm oak woodlands through analyses of leaves and surrounding soils. - De Nicola, F.; Maisto, G.; Alfani, A. (The Science of the total environment, 2003)
The nutritional status and trace element contamination of holm oak woodlands in Vesuvius National Park were assessed by analyses of Quercus ilex L. leaves and surrounding soils. The concentrations of Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, V and Zn were measured in 1-year-old leaves, and in the soils at 0-5 and 15-20 cm depths. The potentially available concentrations were also measured for the soils. The leaf element concentrations were similar to the Q. ilex chemical fingerprint, thus indicating a good nutritional status and the absence of short-term trace element depositions. Total K and V were more abundant in the deep soil layers than in the surface ones, whereas Cd and Pb showed higher values in the surface soils. This suggests that long-term soil accumulations of Cd and Pb are due to atmospheric input. The soil availabilities of Cd, Pb and Zn were high, and Cr availability was very low. A correlation between the available concentrations in the deep soil layers and leaf concentrations was found only for Zn.
The following values have no corresponding Zotero field: accession-num: 12826392
Keywords: Available soil elements; Micro and macro elements; Quercus ilex L.leaves; Total soil elements; Vesuvius National Park

Breeding ecology of Algerian woodchat shrikes Lanius senator: low breeding success - Brahimi, Z.; Dziri, H.; Benyacoub, S.; Chabi, Y.; Banbura, J. (FOLIA ZOOLOGICA, 2003)
Breeding ecology of woodchat shrikes Lanius senator was investigated in the EL-Kala National Park in North-East Algeria (36degrees53'N; 8degrees30'E) in 1998-1999. Quercus suber was the tree species most frequently used as support for nests, which were constructed at a mean height of 5 m. First eggs in clutches were laid 7 May, and clutch size was 4.9. Approximately 42% eggs gave fledglings. Clutch size declined during the course of the breeding season but fledgling success did not. Fledging success was positively correlated with per clutch mean egg length and the height of the nest location above ground. We suggest that the major selective pressures that shape the life history of Algerian woodchat shrikes are relatively heave predation and poor food availability.
The following values have no corresponding Zotero field: pub-location: KVETNA 8, BRNO 603 65, CZECH REPUBLIC publisher: INST VERTEBRATE BIOLOGY AS CR
Keywords: biology; clutch size; egg size; fledging success; nesting; nestling growth; North Africa; passerine

Characterization of semi-extensive goat production systems in southern Spain - Castel, J. M.; Mena, Y.; Delgado-Pertinez, M.; Camunez, J.; Basulto, J.; Caravaca, F.; Guzman-Guerrero, J. L.; Alcalde, M. J. (SMALL RUMINANT RESEARCH, 2003)
This study attempts to describe the semi-extensive goat fanning sector in Andalusia (south of Spain) and to establish characteristics. Eighty-nine goat farmers were surveyed in three areas of this region. The survey examined all aspects of the systems, from socio-economy to management. A multivariate analysis (multiple correspondence and cluster) was used to determine the different farm characteristics. Most of the goat farms studied are single-worker or family managed. The farmers lack training and are elderly, so that continuity of the activity is not assured, although newcomers are usually young. All the farms have some area in ownership, although the farms most specialized in dairy goat products are the smallest in both ownership and total area. The roads are generally in good condition, except on farms with little land, situated in areas of the sierra. Machine-milking installations, closely related to the presence of infrastructures and of goats with a dairy tendency, are generally lacking, (this aspect is improving day by day). Artificial nursing is less generalized than machine-milking. Farms specializing in milk production, whose main activity is dairy goat farming, have dairy specialized breed or crossbred (milk and meat) goats. Feeding depends largely on grazing, with little area being cultivated to produce feed for the goats. Little distinction is made for the production level. Olive or acorn tree branches (Quercus ilex spp.) are used as feedstuff, depending on the types of tree predominating in the area. Five farm types were established, the differences depending on 14 variables of socio-economic aspects, level of production, infrastructure and installations, and feeding. Generated information from this study entails an advance into knowledge of goat farming systems in the Mediterranean area (where little information is generated). The relevance of this study is important since Andalusia has 40% of goats in Spain that produce more than half of the total goat milk in the country, which points out the socio-economical importance for most depressed areas in the region. This work supposes previous steps for improving the semi-extensive goat farming sector. From a methodological point of view, the discussion on variable types and utility establishes farm type characteristics. (C) 2002 Elsevier Science B.V. All rights reserved.
The following values have no corresponding Zotero field: pub-location: PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS publisher: ELSEVIER SCIENCE BV
Keywords: characterization methods; goat systems; semi-extensive farming; southern Spain

The chemistry of precipitation, throughfall and stemflow in two holm oak (Quercus ilex L.) forests under a contrasted pollution environment in NE Spain. - Rodrigo, a; Avila, A.; Roda, F. (The Science of the total environment, 2003)
Atmospheric deposition was studied through measurements of bulk deposition, throughfall and stemflow at two sites of contrasted exposure to pollution in the Montseny mountains (Northeastern Spain). To explore the contribution of local or distant sources at both sites, concentration data and precipitation amounts (log transformed) for both bulk deposition and net throughfall were fitted by linear regression. These models indicated the more important contribution of washout scavenging processes and dry deposition at the pollution exposed site. This is relevant in the context of Mediterranean holm oak forests: up to now, most of the studies have been conducted in protected remote sites and were little representative of the fluxes in forests close to industrial activity, traffic, agriculture and residential areas.
The following values have no corresponding Zotero field: accession-num: 12670768
Keywords: bulk deposition; Dry deposition; Holm oak forest; Leaching; N uptake; throughfall

Comparison between ethanol and hexane for oil extraction from Quercus suber L. fruits - Ferreira-Dias, Suzana; Valente, Dina G.; Abreu, José M. F. (Grasas y Aceites, 2003)
The aim of this study was to (i) evaluate the feasibility of replacing n -hexane with ethanol for the extraction of oil from Quercus suber fruits and (ii) optimize, at lab scale, sample preparation and extraction time for both solvents used ( n -hexane vs . anhydrous ethanol). For both solvents, the effect of the conditioning process on extraction yield was evaluated. Therefore, a full factorial design was used as a function of four variables: dehulling (with vs . without husks), and thermal treatment of the crushed material (40ºC vs . 75ºC), at different times (5 min vs . 120 min) and pressures (10 kPa vs. 100 kPa). Higher oil yields were obtained with n -hexane when dehulled fruits were conditioned under atmospheric pressure. Better yields were obtained with n -hexane, when dehulled material was treated at 75ºC for 90 min. Ethanol was not adequate for oil extraction from Quercus fruits, since other materials rather than oil were also extracted.
Keywords: acorns; Ethanol; Extraction; Hexane; Oil; Quercus

Comparison of the post-fire dynamics of the ectomycorrhizal community in two Quercus ilex stands in Northern Spain - CLAVERÍA, V.; DE MIGUEL, A. M.; DE ROMÁN, M. (Publ. Bio. Univ. Navarra, Ser. Bot.,, 2003)
A comparative study of the post-fire recolonization of ectomycorrhizae in two evergreen oak stands (Quercus ilex L. subsp. ballota (Desf.) Samp.) in Nazar and San Cristóbal (Navarra, Spain) has been carried out. In 1993 a stand in Nazar burnt, but it was not until 1998 that the study started. On the contrary, the study in San Cristóbal started immediately after the stand had caught fire in 2000. Therefore we have been able to compare the regeneration in both stands and the species composition five years after the fire and immediately after the fire, as well as the differences in ectomycorrhizal colonization and abundance of morphotypes between the burnt plots and areas which remained undisturbed in both forests, thus acting as control plots. In both sites the percentage of ectomycorrhizal colonization tended to be lower after the wildfire. In San Cristóbal, in the burnt site there was a lower abundance of morphotypes compared to the control site. However, in Nazar, five years after the fire, we did not find any significant change in species richness, but rather a shift in the abundance of each morphotype when comparing the burnt and the control plots. There are some species of mycorrhizal fungi which seem to be particularly adapted to fire, such as Type 1 in San Cristóbal and Cenococcum geophilum in Nazar. Sphaerosporella brunnea, a pioneer species considered to be especially suitable for the colonization of burnt substrates, was only found in Nazar.
Keywords: Ectomycorrhizae; fire; Quercus ilex; succession

The composition of the diet of red deer (Cervus elaphus) in a Mediterranean environment: a case of summer nutritional constraint? - Bugalho, Miguel N.; Milne, John a (Forest Ecology and Management, 2003)
The composition of the diet of red deer (Cervus elaphus) in a Mediterranean environment, in southern Portugal, was estimated during summer 1995–1997 using n-alkane analysis. Standing crop of herbage layer biomass was estimated between June and September 1995–1997 using the clipping quadrat method. There was a large variability between years in the availability of the herbage layer biomass. Biomass was three fold greater and availability of legumes higher in a wet than in a dry year. Live green material was available in the herbage layer in June, but not thereafter, even during a wet year. Red deer ingested a higher proportion of browse in summer during drier years (0.83–0.89) than during a wet year (0.47). In the drier years, the herbage layer was replaced in the diet by browse species that were uneaten in the wet year. Contrary to Atlantic environments, where red deer include a large proportion of browse in their diets during winter, summer is likely to be a season of nutritional constraint for red deer inhabiting Mediterranean environments
Keywords: browse; cervus elaphus; diet composition; Mediterranean

Decline in photosynthetic nitrogen use efficiency with leaf age and nitrogen resorption as determinants of leaf life span - Escudero, A.; Mediavilla, S. (Journal of Ecology, 2003)
* 1Cost-benefit models predict that leaf life span depends on its initial photosynthetic rate and construction cost and on the rate of decline in photosynthesis with age. Leaf gas exchange rates and N contents were measured in nine woody evergreen Mediterranean species with different leaf life spans to determine the effects of leaf ageing on photosynthetic N use efficiency (PNUE). N costs of leaf construction were assumed to be in part dependent on N resorption from senescing leaves. * 2Leaf ageing had significant negative effects on photosynthetic rates per unit leaf area. As N content per unit leaf area did not decline until the end of leaf life, PNUE also decreased with age. PNUE generally declined faster in species with a shorter leaf life span. There were no significant interspecific differences in maximum CO2 assimilation rates per unit leaf area and in N resorption that could be related to differences in leaf life span. * 3As PNUE decreases with leaf age, shedding of the older leaves and retranslocation of N to the current year's leaf biomass would result in an increase in the mean instantaneous efficiency of use of the N retranslocated. However, total CO2 assimilation can be improved by such shedding only when the increase in the efficiency of use of the remobilized N compensates for the remaining N lost in the shed leaves. * 4The photosynthesis of the old leaf cohorts exceeded the increase in photosynthesis that would be obtained from the N retranslocated to the younger leaves, given the observed efficiencies of N resorption. The retention of old leaves thus resulted in a higher whole-canopy CO2 assimilation, despite their low PNUE.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd
Keywords: leaf life span; N resorption; photosynthetic nitrogen use efficiency; Pinus spp.; Quercus spp

Degradation of vanillic acid and production of guaiacol by microorganisms isolated from cork samples - Álvarez-Rodríguez, María Luisa; Belloch, Carmela; Villa, Mercedes; Uruburu, Federico; Larriba, Germán; Coque, Juan-José R. (FEMS Microbiology Letters, 2003)
The presence of guaiacol in cork stoppers is responsible for some cases of cork taint causing unpleasant alterations to wine. We have performed a characterization of the cork-associated microbiota by isolating 55 different microorganisms: eight yeast, 14 filamentous fungi or molds, 13 actinomycetes and 20 non-filamentous bacteria. A screening for degradation of vanillic acid and guaiacol production showed that none of the filamentous fungi could achieve any of these processes. By contrast, five of the eight yeast strains isolated were able to degrade vanillic acid, although it was not converted to guaiacol. Guaiacol production was only detected in four bacterial strains: one isolate of Bacillus subtilis and three actinomycetes, Streptomyces sp. A3, Streptomyces sp. A5 and Streptomyces sp. A13, were able to accumulate this compound in both liquid media and cultures over cork. These results suggest that guaiacol-mediated cork taint should be attributed to the degradative action of vanillic acid by bacterial strains growing on cork.
The following values have no corresponding Zotero field: publisher: Blackwell Publishing Ltd
Keywords: Cork taint; Guaiacol; Vanillic acid; Wine aroma

Diplopyrone, a New Phytotoxic Tetrahydropyranpyran-2-one Produced by Diplodia mutila, a Fungus Pathogen of Cork Oak - Evidente, Antonio; Maddau, Lucia; Spanu, Emanuela; Franceschini, Antonio; Lazzaroni, Silvia; Motta, Andrea (Journal of Natural Products, 2003)
A new phytotoxic monosubstituted tetrahydropyranpyran-2-one, named diplopyrone (1), was isolated from the liquid culture filtrates of Diplodia mutila, a plant pathogenic fungus causing a form of canker disease of cork oak (Quercus suber). Diplopyrone was characterized, using spectroscopic and chemical methods, as 6-[(1S)-1-hydroxyethyl]-2,4a,6,8a-tetrahydropyran[3,2-b]pyran-2-one. The absolute stereochemistry of the chiral secondary hydroxylated carbon (C-9), determined by application of Mosher's method, proved to be S. Diplopyrone assayed at a 0.01?0.1 mg/mL concentration range caused necrosis and wilting on cork oak cuttings. On a nonhost plant, tomato, diplopyrone caused brown discoloration or stewing on the stem.
The following values have no corresponding Zotero field: publisher: American Chemical Society accession-num: 12608876
Keywords: Phytopathogenic fungi; Phytotoxins; relative and/or absolute configuration; structure–activity relationships

Diversidad biológica y sostenibilidad ecológica y económica de los sistemas adehesados - Díaz, M.; Pulido, F. J.; MARAÑON, T. (Ecosistemas, 2003)
Los bosques mediterráneos son sistemas naturales con una elevada diversidad biológica, que tiende a aumentar cuando son explotados para formar dehesas arboladas. Dentro de este sistema de explotación, la riqueza de especies varía en función de los efectos del manejo humano sobre la estructura de la vegetación, tanto subarbórea (presencia de cultivos de cereal o manchas de matorral) como arbórea (densidad de árboles). Estas tendencias se observan en varios grupos de organismos y para un amplio rango de escalas espaciales, y parecen deberse a la íntima coexistencia espacial en las dehesas de elementos faunísticos y florísticos forestales, asociados al arbolado y al matorral, y de elementos propios de zonas abiertas, asociados a los pastizales y cultivos sobre los que crecen los árboles. La coexistencia a escala de finca de distintos usos, así como la coexistencia de las dehesas y otros hábitats a escala regional, contribuyen al mantenimiento de especies adicionales. No obstante, se requieren perturbaciones como el fuego o el uso humano, que serían las causas últimas de esta diversidad. La diversidad biológica de las dehesas podría contribuir a su sostenibilidad económica si èsta es valorada adecuadamente por la sociedad. Además, se requerirían medidas adicionales que garantizasen situaciones temporales de menor diversidad pero indispensables para la regeneración del arbolado y la sostenibilidad ecológica de este peculiar sistema de explotación.

Efeito da Idade e da Fertilização na Qualidade das Plantas do Sobreiro (Quercus - Merouani, Hachemi; Costa, Filipe; Sampaio, Teresa; Lourenço, Maria João; Pereira, João Santos; Almeida, Maria Helena (Congresso Florestal Nacional, 5º, Viseu, 2005, 2003)
A plantação tem sido uma técnica muito utilizada em projectos de reflorestação do montado de sobro, uma vez que a sementeira é limitada temporalmente pelo facto de não se dominar a conservação a longo prazo das glandes (sementes recalcitrantes). Consequentemente, a produção das plantas provém exclusivamente de sementes frescas (Novembro - Janeiro) condicionando a sua idade no momento da plantação (10-14 meses). A idade da planta influencia o seu potencial de crescimento após a plantação, estando regulamentada por legislação (DecretoLei nº 205/2000, de 12 de Setembro). A aplicação de fertilizantes tem sido sugerida como uma técnica de produção em viveiro destinada a melhorar a qualidade da planta. No âmbito de diversos projectos (CREOAK-QLK5-CT-2002-01594; POCTI/41359/AGG/2001), temos vindo a aprofundar o conhecimento sobre a qualidade das plantas do sobreiro. Produziram-se em viveiro, plantas de idade diferente provenientes de sementes frescas e conservadas (3 e 6 meses), obtendo-se respectivamente plantas de 9, 7 e 5 meses. Nas plantas de 7 meses, foi aplicado um tratamento de fertilização (50 ml da solução NPK, 12-2-12) e de micorrização (Pisolithus tinctorius). Foram avaliados diferentes parâmetros morfológicos e fisiológicos durante a fase de crescimento da planta em viveiro, assim como o potencial de crescimento das raízes no momento de plantação. Os resultados apresentados centram-se no efeito de ambos os factores (idade à plantação e fertilização) na qualidade das plantas.
The following values have no corresponding Zotero field: periodical: Congresso Florestal Nacional, 5º, Viseu, 2005
Keywords: Conservação de glandes; idade da planta; Material Florestal de Reprodução; Q. suber; Qualidade

Effect of nursery location and outplanting date on field performance of Pinus halepensis and Quercus ilex seedlings - Pardos, M.; Royo, A.; Gil, L.; Pardos, J. A. (Forestry, 2003)
One-year-old seedlings of Aleppo pine (Pinus halepensis Mill.) and holm oak (Quercus ilex L.) were over-wintered in the nursery under two contrasting conditions (greenhouse vs outdoors), which were chosen to simulate coastal vs inland thermal regimes. Seedling morphology, root growth potential (RGP) and shoot cold hardiness were assessed at lifting (at monthly intervals from November to March), and related to survival and field performance during two growing seasons. At lifting, behaviour outdoors was similar in both species. Conversely, the milder conditions in the greenhouse affected nursery performance in Aleppo pine seedlings (shoot growth during winter, low cold hardiness, low RGP), and influenced field performance negatively. Thus, nursery thermal regime had a significant effect on survival of outplanted Aleppo pine seedlings, and autumn outplanting appears to be the preferred option for this species. This issue does not seem as relevant in holm oak, a species less sensitive to frost. Minimum field temperatures in the 3 weeks around outplanting date were a critical acclimation period for Aleppo pine seedlings. Higher RGP at lifting was related to higher survival in Aleppo pine and taller holm oak seedlings. There was also a significant correlation between mortality after outplanting and foliar electrolyte leakage in Aleppo pine. Thus, cold hardiness is a good physiological indicator for determining the best lifting and planting dates in Aleppo pine, and RGP shows more promise for assessing holm oak vitality.
10.1093/forestry/76.1.6710.1093/forestry/76.1.67
Keywords: nursery location; outplanting; Pinus halepensis; Quercus ilex; Root growth; seedlings; shoot growth; survival (voyant)

Effects of tension wood on specific conductivity and vulnerability to embolism of Quercus ilex seedlings grown at two atmospheric CO2 concentrations - Gartner, Barbara L.; Roy, Jacques; Huc, Roland (Tree Physiology, 2003)
To determine whether there are decreases in hydraulic function of a woody stem when it has increased mechanical loading, Quercus ilex L. seedlings were grown upright or inclined to force the production of large amounts of tension wood (TW). Seedlings were grown in ambient or elevated carbon dioxide concentrations ([CO2]) for 16–17 months to provide two sets of seedlings differing in growth rates and allocation patterns. In both CO2 environments, inclination caused formation of large amounts of TW at the base and mid-section of most stems, but not at the stem tips. Contrary to expectation, there were no significant effects of stem inclination or amount of TW on specific conductivity (ks) or vulnerability to embolism. Samples with high amounts of TW had higher vessel frequency, similar average vessel lumen area, similar vessel lumen fraction (6% of the transverse area), elevated frequency of vessels in the smallest diameter class, and higher wood density than samples with very little TW. Samples from seedlings in the elevated [CO2] treatment had similar vessel frequency, larger average vessel lumen area (caused by a higher frequency of large-diameter vessels), similar vessel lumen fraction, and similar wood density as samples from seedlings in the ambient [CO2] treatment. There was a strong position effect: the highest wood density and lowest ks were at the stem base, intermediate values were at the middle, and the lowest density and highest ks were at the stem tip. We conclude that, in a species that uses different cells for mechanical support and water transport, there can be large modifications in performance of the mechanical function through TW formation without impacting the water transport functions—ks and vulnerability to embolism.
10.1093/treephys/23.6.38710.1093/treephys/23.6.387
Keywords: ecological wood anatomy; evergreen; hydraulic architecture; Mediterranean; structure/function relationship

The epiphytic bryoflora of the Jbel Bouhalla (Rif, Morocco), including a new variety of moss, Orthotrichum speciosum var. brevisetum. - Draper, I.; Lara, F.; Albertos, B.; Garilleti, R.; Mazimpaka, V. (Journal of Bryology, 2003)
The epiphytic bryoflora of Jbel Bouhalla, a mountain sited in the Rif range (northern Morocco), is catalogued, resulting in a list of 48 taxa (45 mosses and 3 liverworts). One new variety, Orthotrichum speciosum var. brevisetum, is described, and some new records are reported: Orthotrichum shawii and O. pallens are new to northern Africa, while Habrodon perpusillus and O. speciosum var. speciosum are new to Morocco. [ABSTRACT FROM AUTHOR]
Keywords: Bryophyte flora; chorology; epiphytes; Morocco; northern Africa; Orthotrichum speciosum var. brevisetum; Rif

Ergovaline occurrence in grasses infected by fungal endophytes of semi-arid pastures in Spain - Vazquez de Aldana, Beatriz R.; Zabalgogeazcoa, Iigo; Garcia Ciudad, Antonia; Garcia Criado, Balbino (Journal of the Science of Food and Agriculture, 2003)
: Ergovaline is a mycotoxin produced by fungal endophytes belonging to Neotyphodium and Epichloe¨ spp in several host grass species. Owing to the production of this alkaloid, the ingestion of endophyte-infected grasses causes toxicosis in grazing animals. The aim of this work was to determine if ergovaline is produced in several grasses (Agrostis castellana Boiss and Reuter, Brachypodium phoenicoides (L) Roemer and Schultes, Dactylis glomerata L, Festuca arundinacea Schreb, Festuca arundinacea Schreb subsp fenas (Lag) Arcangeli, Festuca ovina L, Festuca rubra L, Holcus lanatus L and Lolium perenne L) infected by fungal endophytes in ‘dehesa’ pastures in Spain. Forage and seed samples of several ecotypes of these grass species were analysed for their ergovaline content by HPLC with ﬂuorescence detection. The ergovaline content ranged between 0.03 and 0.85mg g 1 in forage and 0.28 and 3.17mg g 1 in seed samples of F arundinacea, between 0.00 and 0.08mg g 1 in forage and 0.02 and 0.19mg g 1 in seed samples of F rubra, between 0.00 and 0.02mg g 1 in forage samples of H lanatus, and was 0.11mg g 1 in one ecotype of F ovina. All nine ecotypes of F rubra had ergovaline in seed samples, but in three ecotypes the alkaloid was not detected in forage samples. No ergovaline was detected in the other four endophyte-infected grasses analysed. The ergovaline content should be considered as an anti-quality parameter to be measured when the nutritional quality of these pastures is evaluated
Keywords: dehesa grasslands; endophytes; epichloe; ergovaline; mycotoxins; neotyphodium

Fatty acid composition of abdominal adipose tissue in broilers fed green-oak (Quercus ilex), cork oak acorn (Quercus Suber L.) based diets - Bouderoua, Kaddour; Selselet-Attou, Ghalem (Anim. Res., 2003)
Male broilers, 30 for every diet, were fed for six weeks, diets containing 60% green oak (GO) and oak cork (CO) acorns compared to 60% corn (C). The body weight of the chickens fed the oak acorn-based diets was 25% lower than that of the controls (C). Abdominal adipose tissue (AAT) was twice heavier in the controls compared to broilers fed oak acorn-based diets. The total lipids of AAT were higher in the controls compared to the oak acorn fed chickens (34.4 against 15.3 g per 100 g of AAT in the CO). The palmitic and oleic acid proportions were comparable in the AAT of chickens fed with the different diets. The proportion of linoleic acid, obtained exclusively by the diets, was significantly higher in the chickens fed oak acorn-based diets (23%), compared to the controls (19%). Reciprocally, palmitoleic acid was present in a small proportion in chickens fed oak acorns (4 to 5%). The observed variation of the fatty acid content of abdominal fat of acorn-fed chickens requires further research on the precise nutrient digestibility of oak acorns before considering them as a potential feed.
Keywords: Adipose Tissue; broilers; Lipids; lipogenesis; oak acorn

Fruit abortion, developmental selection and developmental stability in Quercus ilex. - Díaz, Mario; Møller, Anders P.; Pulido, Fernando J. (Oecologia, 2003)
Fruit abortion has been hypothesized to be a parental means of selective removal of propagules with low viability. In particular, aborted zygotes have been suggested to have developmentally deviant phenotypes, and surviving offspring may therefore give rise to adults with a developmentally stable phenotype. We tested predictions from this hypothesis using acorns of holm oaks Quercus ilex as a model system. Fecundity of oak trees was negatively related to mean fluctuating asymmetry of leaves, and abortion rates were positively related to leaf fluctuating asymmetry in at least one population. Aborted acorns were asymmetric in 83-99% of cases in three samples, while mature acorns were only asymmetric in 57-78% of cases. Acorn asymmetry was unrelated to germination probability and germination date, and had no significant effect on number of leaves, leaf mass, stem mass, seedling height or leaf area of seedlings. However, acorn asymmetry affected the trade-off between number and size of leaves in seedlings. Seedlings from asymmetric acorns showed a positive relationship between acorn size and number of leaves, but no relationships between acorn size and leaf area, while symmetric acorns showed the opposite. A positive relationship between acorn size and number of leaves in spring was found for naturally emerged seedlings that died during their first summer, whereas the number of leaves produced by surviving seedlings did not depend on acorn size. These findings are consistent with the hypothesis that stressed trees selectively abort propagules of low viability, and that developmental selection acts on a measure of developmental instability of fruits.
The following values have no corresponding Zotero field: accession-num: 12721827
Keywords: acorn; Fluctuating asymmetry; Leaf number; Leaf size; Maternal effect

A global change-induced biome shift in the Montseny mountains (NE Spain) - Penuelas, Josep; Boada, Martí (Global Change Biology, 2003)
Shifts in plant species and biome distribution in response to warming have been described in past climate changes. However, reported evidence of such shifts under current climate change is still scarce. By comparing current and 1945 vegetation distribution in the Montseny mountains (Catalonia, NE Spain), we report here a progressive replacement of cold-temperate ecosystems by Mediterranean ecosystems. Beech (Fagus sylvatica) forest has shifted altitudinally upwards by ca. 70 m at the highest altitudes (1600–1700 m). Both the beech forests and the heather (Calluna vulgaris) heathlands are being replaced by holm oak (Quercus ilex) forest at medium altitudes (800–1400 m). This beech replacement has been observed to occur through a progressive isolation and degradation of beech stands. In ‘isolated’ (small and surrounded by holm oaks) beech stands, beech trees are 30% more defoliated, beech recruitment is 41% lower, and holm oak recruitment is three times higher than in ‘continental’ (large and continuous) beech stands. The progressively warmer conditions, complemented by the land use changes (mainly the cessation of traditional land management) are the apparent causes, providing a paradigmatic example of global change affecting distributions of plant species and biomes.
The following values have no corresponding Zotero field: publisher: Blackwell Science, Ltd
Keywords: altitudinal shift; biome replacement; Calluna heathland; climate change; defoliation status; Fagus sylvatica; Land use change; mediterranean forest; Montseny mountains; Quercus ilex; Recruitment; temperate forest

Habitat effects and shooting techniques on two wild boar (Sus scrofa) populations in Spain and Portugal - Fernandez-Llario, P.; Mateos-Quesada, P.; Silvério, A.; Santos, P. (Zeitschrift für Jagdwissenschaft, 2003)
In the last decades, wild boar (Sus scrofa) distribution has increased world-wide, the Iberian Peninsula being no exception. The wild boar now inhabits almost the entire Iberian territory, where today it is one of the most important big game species. In this paper, for the first time, bag analysis from two ecological different regions are presented and compared to the employed hunting techniques. One represents the well-preserved Mediterranean forests of south-western Spain, the other, located in the south of Portugal, is a farmland with interspersed forest areas. Our results indicate a stronger hunting intensity and also a higher wild boar population density in the Portuguese study areas. The stronger hunting intensity may result in a younger wild boar population. We also found considerable differences between the shooting techniques used in both regions and those employed in the north-east of the peninsula. It does therefore not seem advisable to directly compare bag statistics from different regions of the Iberian peninsula.
Keywords: habitats; Mediterranean; Populations; Portugal; shooting techniques; Spain; Sus scrofa; Wild boar

Hydrological properties of cork container media - Carmona, E.; Ordovas, J.; Moreno, M. T.; Aviles, M.; Aguado, M. T.; Ortega, M. C. (HORTSCIENCE, 2003)
Static hydrological properties \{[\}aeration capacity; easily available water, reserve water, water release curves: theta(v)(Psi(m)), and specific humidity curves] and dynamic hydrological properties (saturated and unsaturated hydraulic conductivity) of substrates based on industrial cork residue (the bark of Quercus suber L.) and cork compost were studied. Samples of similar granulometry have been used to establish the effect of cork composting on the aforementioned physical properties. Different models were tested to describe the mechanism of water release from these materials. Van Genuchten's model (Van Genuchten, 1978) was the best fit and produced specific humidity curves that revealed slight differences in the ratio of water capacity function. When cork residues were composted for 7 months, important changes occurred in hydrological properties of the material as it became more wettable. Water retention significantly increased from 45% to 54%, at a potential of 5 kPa, although this did not necessarily result in increased water available to plants. A study of the unsaturated hydraulic conductivity (K-unsat) of these materials revealed a significant decrease in the K-unsat water potential at 0-5 kPa, which corresponds to the range in which the irrigation with these substrates was usually carried out. The long composting process resulted in increased K-unsat between 4 and 5 times that of uncomposted material, which would improve the water supply to the plant.
The following values have no corresponding Zotero field: pub-location: 113 S WEST ST, STE 200, ALEXANDRIA, VA 22314-2851 USA publisher: AMER SOC HORTICULTURAL SCIENCE
Keywords: growing media; horticultural substrate; hydraulic conductivity; physical properties; water release curves

Identification, measurement and interpretation of tree rings in woody species from mediterranean climates. - Cherubini, Paolo; Gartner, Barbara L.; Tognetti, Roberto; Bräker, Otto U.; Schoch, Werner; INNES, JOHN L. (Biological reviews of the Cambridge Philosophical Society, 2003)
We review the literature dealing with mediterranean climate, vegetation, phenology and ecophysiology relevant to the understanding of tree-ring formation in mediterranean regions. Tree rings have been used extensively in temperate regions to reconstruct responses of forests to past environmental changes. In mediterranean regions, studies of tree rings are scarce, despite their potential for understanding and predicting the effects of global change on important ecological processes such as desertification. In mediterranean regions, due to the great spatio-temporal variability of mediterranean environmental conditions, tree rings are sometimes not formed. Often, clear seasonality is lacking, and vegetation activity is not always associated with regular dormancy periods. We present examples of tree-ring morphology of five species (Arbutus unedo, Fraxinus ornus, Quercus cerris, Q. ilex, Q. pubescens) sampled in Tuscany, Italy, focusing on the difficulties we encountered during the dating. We present an interpretation of anomalies found in the wood structure and, more generally, of cambial activity in such environments. Furthermore, we propose a classification of tree-ring formation in mediterranean environments. Mediterranean tree rings can be dated and used for dendrochronological purposes, but great care should be taken in selecting sampling sites, species and sample trees.
The following values have no corresponding Zotero field: accession-num: 12620063
Keywords: Arbutus unedo; Dendrochronology; Dendroecology; ecophysiology; Fraxinus ornus; Mediterranean climate; mediterranean tree rings; Mediterranean vegetation; Phenology; Quercus cerris; Quercus ilex; Quercus pubescens; wood anatomy

Imaging the mechanical properties of wood cell wall layers by atomic force modulation microscopy - Clair, B.; Arinero, R.; Leveque, G.; Ramonda, M.; Thibaut, B. (IAWA JOURNAL, 2003)
Atomic Force Microscopy in force modulation mode was used to study the elastic properties of the different fibre wall layers of the tension wood of holm oak and normal wood of boco. The method is based on the measurement of the resonance frequency of the microscope lever in contact with the sample. This frequency is related to the reduced Young modulus E{*} = E/(1-nu(2)) of the material, supposed to be isotropic. `Elastic' images of the cell are obtained simultaneously with the topographic images, which allows the observation of the mechanical properties of the cells at a nanometric scale. Layers G, S-1, S-2 and ML can clearly be distinguished. By comparison with known materials an estimation of the absolute modulus is given in the range 5-20 GPa, but should be considered with caution, because the inherent anisotropy of the materials has not been taken into account.
The following values have no corresponding Zotero field: pub-location: RIJKSHERBARIUM, PO BOX 9514, 2300 LEIDEN, NETHERLANDS publisher: INT ASSOC WOOD ANATOMISTS
Keywords: atomic force microscopy; cell wall; elastic modulus; mechanical properties; Wood

In vitro floral induction from thin longitudinal sections and micro-cuttings of juvenile cork oak material - Mulin, Manorama; Pais, M. S. S. (Trees-Structure and Function, 2003)
In vitro flowers were obtained from thin longitudinal sections excised at the proximity of the apical region or nodal regions of the main stem and axillary shoots of in vitro Quercus suber stock shoots as well as from field-grown seedlings. In vitro floral induction was also achieved from nodal segments of 8- to 9-month-old seedlings or from micro-cuttings of embryonic main shoot and its axillary shoots of 2- month-old seedlings. The more juvenile the material the shorter the period required to achieve flowering. Under the described experimental conditions we have thus been able to induce the expression of neoteny in a woody, longcycle species such as cork oak.
Keywords: apical or nodal regions; floral induction; neoteny; nodal segments or micro-cuttings; thin longitudinal sections

Influence of fire severity on plant regeneration by means of remote sensing imagery - Díaz-Delgado, R.; Lloret, F.; Pons, X. (International Journal of Remote Sensing, 2003)
In this paper we analyse the interactions between fire severity (plant damage) and plant regeneration after fire by means of remote sensing imagery and a field fire severity map. A severity map was constructed over a large fire (2692 ha) occurring in July 1994 in the Barcelona province (north-east of Spain). Seven severity classes were assigned to the apparent plant damage as a function of burning intensity. Several Landsat TM and MSS images from dates immediately before and after the fire were employed to monitor plant regeneration processes as well as to evaluate the relationship with fire severity observed in situ . Plant regeneration was monitored using NDVI measurements (average class values standardized with neighbour unburned control plots). Pre-fire NDVI measurements were extracted for every plant cover category (7), field fire severity class (7), and spatial cross-tabulation of both layers (33) and compared to post-fire values. NDVI decline due to fire was positively correlated with field fire severity class. Results show different patterns of recovery for each dominant species, severity class and combination of both factors. For all cases a significant negative correlation was found between damage and regeneration ability. This work leads to a better understanding of the influence of severity, a major fire regime parameter on plant regeneration, and may aid to manage restoration on areas burned under different fire severity levels.
doi: 10.1080/01431160210144732doi: 10.1080/01431160210144732The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: dominant species (voyant); fire severity; NDVI; plant damage; plant regeneration

Large-scale environmental correlates of forest tree distributions in Catalonia (NE Spain) - Thuiller, Wilfried; Vayreda, Jordi; Pino, Joan; Sabaté, Santi; Lavorel, Sandra; Gracia, Carles (Global Ecology and Biogeography, 2003)
Aim To explore the environmental correlates of tree species distributions in Catalonia according to the chorological status of the species. Location The study area is the region of Catalonia, in northeastern Spain. Methods We used presence-absence data for 24 species, sampled in random plots distributed throughout forests of Catalonia. A climate model for the Catalonia region provided environmental variables. We used classiﬁcation tree analysis to explore the environmental correlates of the realized niches of tree species. The predictive accuracy of the models was assessed using the ROC curve approach. Potential distribution maps of tree species were generated for the whole Catalonia region. Results Models were ranked from low to high accuracy for the 24 species. Differences in accuracy among species were related to the chorological status of species. Zonal species, or species at the core of their range (Mediterranean and SubMediterranean species), were generally well predicted, while extrazonal species, or species at the edge of their range, were predicted only moderately well. Mediterranean species distributions showed good correlations with extreme temperatures and annual precipitation. Main conclusions The above trends conﬁrmed the difﬁculty of identifying the realized niche of species at the edges of their ranges. In contrast, Mediterranean and Sub-Mediterranean species, which were at the core of their range, were well-predicted, conﬁrming the importance of extremes of temperature and annual precipitation as effective surrogates for variables having more direct physiological roles in limiting the ability of plants to survive and grow. Maps of potential tree distributions allowed us to deﬁne suitable habitats and to highlight areas where species have been planted outside their natural distribution.
Keywords: chorology; classification tree analysis; environmental gradients; forest trees; potential distribution maps; realized niche; Spain

Leaf life span differs from retention time of biomass and nutrients in the crowns of evergreen species - Mediavilla, S.; Escudero, A. (Functional Ecology, 2003)
* 1A long leaf life span has been interpreted as an adaptation to low nutrient availability. It is commonly assumed that a long leaf life span permits a longer utilization of nutrients in the leaf biomass and that this contributes to improving nutrient use efficiency. However, a long leaf life span is also associated with other leaf traits that reduce instantaneous productivity, which might reduce the growth rate of the leaf biomass and shorten the functional life of the leaf. * 2We studied the relationships between leaf life span and the retention time of biomass and nutrient pools in several woody species with different leaf life spans. We measured the monthly variations in the total number of leaves per annual shoot, mass per leaf, and N and P contents per leaf. With these data, the leaf life span and the mean residence time (MRT) of leaf biomass and nutrient pools were estimated. * 3The increase in the total number of leaves was fast in all species studied at the start of the growth season. In contrast, in evergreen species mass per leaf and total N and P contents per leaf increased gradually after the first year of life of the leaves, and the maximum mass and nutrient contents per leaf were attained only towards the end of the lifetime of the leaves. * 4Owing to the delay in the development of mass and nutrient pools with respect to leaf number dynamics, in evergreen species leaf life span was longer than the MRT of leaf biomass and nutrient pools because part of the leaf biomass and nutrient pool remained in the crown for a shorter time than the mean duration of the individual leaves. * 5The differences between leaf life span and the MRT of the biomass and nutrients increased with leaf life span. The slow growth of evergreen leaves therefore contributes to reduce the adaptive value of a long leaf life span as a mechanism to increase the duration of the photosynthetic machinery.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd
Keywords: Leaf growth; leaf life span; mean residence time; nitrogen; phosphorus

Management problems in Mediterranean cork oak forests: post-fire recovery - Barberis, a; Dettori, S.; Filigheddu, M. R. (Journal of Arid Environments, 2003)
The objective of this paper is to present the results of a long-term research project carried out in north-east Sardinia, which aims to evaluate the effects of three different kinds of forest management (traditional trunk coppicing, branch pruning, and no sylvicultural practice) on the post-fire recovery of a cork oak (Quercus suber L.) stand. The most and the least effective forestry operations appeared to be traditional trunk coppicing and the branch pruning, respectively. Where traditional trunk coppicing is considered strictly necessary, the opportunity of thinning some of the new suckers should be carefully considered, as modern harvesting techniques should be combined with appropriate strategies to protect the soil from erosion.
Keywords: post-fire recovery; suckers growth

Maturation and germination of oak somatic embryos originated from leaf and stem explants: RAPD markers for genetic analysis of regenerants. - Sánchez, M. Concepción; Martínez, M. Teresa; Valladares, Silvia; Ferro, Enrique; Viéitez, Ana M. (Journal of plant physiology, 2003)
Experiments were performed to determine the influence of maturation medium carbohydrate content on the rates of germination and plantlet conversion (root and shoot growth) of somatic embryos from four embryogenic lines derived from leaf or internode explants of Quercus robur L. seedlings. The conversion rate was favoured by high carbohydrate content as long as the maturation medium contained at least 2% sucrose, which was necessary for healthy embryo development. Given this, sorbitol and mannitol favoured the conversion rate more efficiently than sucrose, the highest rate, 32%, being achieved by medium with 6% sorbitol and 3% sucrose. Maturation treatment did not affect the root or shoot lengths of converted embryos. In supplementary experiments, 2 weeks of gibberellic acid treatment between maturation and germination treatments did not improve germination rates, but did reduce root length and the number of leaves per regenerated plantlet. In the four embryogenic lines tested, plant recovery rate was enhanced by inclusion of benzyladenine into the germination medium following culture of the embryos on maturation medium with 6% sorbitol and 2-3% sucrose. In embryogenic systems it is important to assess the uniformity of the regenerants. Random amplified polymorphic DNA (RAPD) analysis using 32 arbitrary oligonucleotide primers was performed to study variability in DNA sequences within and between four embryogenic lines. No intraclonal nor interclonal polymorphism was detected between embryogenic lines originating from different types of explant from the same seedling, but every one of the primers detected enough polymorphism among clones originating from different plants to allow these three origins to be distinguished. No differences in DNA sequences between regenerated plantlets and their somatic embryos of origin were detected, but a nodular callus line that had lost its embryogenic capacity was found to be mutant with respect to three other clones originating from the same plantlet. This study shows that high carbohydrate levels in the maturation medium significantly increase plant conversion of oak somatic embryos, which exhibit no variation in DNA sequences when proliferated by secondary embryogenesis.
The following values have no corresponding Zotero field: accession-num: 12872492
Keywords: DNA polymorphism; genetic stability; plant conversion; Quercus robur; Somatic embryogenesis

Microspore-derived embryos from Quercus suber anthers mimic zygotic embryos and maintain haploidy in long-term anther culture. - Bueno, María a; Gomez, Arancha; Sepulveda, Federico; Seguí, José M.; Testillano, Pilar S.; Manzanera, Jose a; Risueño, Maria-Carmen (Journal of plant physiology, 2003)
Microspore-derived embryos produced from cork oak anther cultures after long-term incubations (up to 10-12 months) were analysed in order to determine the genetic variability and ploidy level stability, as well as morphology, developmental pattern and cellular organisation. Most of the embryos from long-term anther cultures were haploid (90.7%), corresponding to their microspore origin. The presence of a low percentage of diploid embryos (7.4%) was observed. Microsatellite analysis of haploid embryos, indicated different microspores origins of the same anther. In the diploid embryos, homozygosity for different alleles was detected from anther wall tissues, excluding the possibility of clonal origin. The maintenance of a high proportion of haploid embryos, in long-term anther cultures, is similar in percentage to that reported in embryos originating after 20 days of plating (Bueno et al. 1997). This suggests that no significant alterations in the ploidy level occurred during long incubations (up to 12 months). These results suggest that ploidy changes are rare in this in vitro system, and do not significantly increase during long-term cultures. Microscopical studies of the microspore embryos in various stages revealed a healthy and well developed anatomy with no aberrant or chimeric structures. The general morphology of embryos appearing at different times after plating, looked similar to that of earlier embryos, as well as the zygotic embryos, indicating that they represent high quality material for cork oak breeding.
The following values have no corresponding Zotero field: accession-num: 12964871
Keywords: Cytochemistry; DNA-Analysis; flow cytometry; haploid embryos; immunocyto- chemistry; Quercus suber L.

Monitoring Leaf Area Index of Mediterranean oak woodlands: Comparison of remotely-sensed estimates with simulations from an ecological process-based model - Garson, D. Caraux; LACAZE, B. (International Journal of Remote Sensing, 2003)
Annual vegetation abundance mapping was carried out within the DeMon II European project over a period of 12 years (1984-1996). The project relied on advanced satellite-based methods for spatial and temporal monitoring of Mediterranean oak woodlands by means of a series of Landsat Thematic Mapper (TM) satellite data. A standardized approach developed previously focuses on the Languedoc site, Hautes Garrigues, a typical sensitive Mediterranean region, but now recovering after centuries of grazing and agricultural activities. After geometric and radiometric rectification of nine full Landsat TM scenes with a refined correction in a smaller area of 75 km 2 75 km, a GIS database was created containing satellite data, thematic maps of vegetation, geological maps, climatic data and field measurements. An empirical relation between radiometric ground truth measurements and satellite derived Normalized Difference Vegetation Index (NDVI) allows us to derive Leaf Area Index (LAI). An ecological process-based model (Forest BGC) has been adapted to simulate ecosystem processes in a satisfying way at a local scale. Consistent results were obtained from remote sensing data and from simulations at a local scale, suggesting the possible use of remote-sensing data to monitor vegetation abundance changes at a regional scale. Without considering human disturbances, it can be noted that not much variation of LAI induced by natural factors can be detected over the considered 12-year period.
doi: 10.1080/0143116021000024267doi: 10.1080/0143116021000024267The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: Annual variation (voyant); green vegetation; Leaf area index (LAI); NDVI; Oak woodlands; Remote sensing

Patterns of structural complexity and human disturbance of riparian vegetation in agricultural landscapes of a Mediterranean area - Corbacho, Casimiro; Sánchez, Juan Manuel; Costillo, Emilio (Agriculture, Ecosystems & Environment, 2003)
Riparian corridors are valuable high diversity habitats in Mediterranean-type environments and mainly in agricultural landscapes. Following a ‘vegetation complexes’ approach along ﬂuvial landscapes, the factors affecting structural complexity and human disturbance through agricultural areas in south-west (SW) Spain were analysed. Using principal component analysis and a stepwise multiple regression analysis three main results were obtained: (1) a successional vegetative gradient was noted from upper (pioneer herbaceous communities) to lower reaches of streams (closed-canopy forests) with a concomitant increase in both woody cover and habitat diversity; (2) land-use intensity associated with each of the agricultural production methods, which was mainly related to topographic irregularity, appeared to be the main cause of human disturbance in riparian areas. Thus, the closed-canopy forests located in ﬂat landscapes of lower streams were removed, highly modiﬁed or extensively fragmented; in contrast, riparian complexes placed on wild and rough landscapes of upper streams appeared as undisturbed or near-natural; (3) nearly 50% of the natural riparian vegetation of the study area has been highly modiﬁed or has disappeared, in most cases replaced by non-natural formations which have today become dominant. The protection of the few existing well-preserved riparian corridors and the restoration of highly altered riparian areas in the lower reaches of streams has become a priority in maintaining biodiversity in these agricultural Mediterranean landscapes. The extensive and cost-effective method developed for this study would be easily applicable to other large areas to evaluate the effect of human disturbance on riparian corridors
Keywords: agricultural landscapes; conservation; Human disturbance; Mediterranean areas; Riparian vegetation; Successional vegetative gradient; SW Spain

Photoprotection in evergreen Mediterranean plants during sudden periods of intense cold weather - García-Plazaola, J. I.; Olano, J. M. (Trees-Structure and …, 2003)
The photoprotective responses to an abrupt period of exceptional cold weather were studied in several Mediterranean evergreen species with different ecological requirements. The same pattern of response was observed in most of the species with little change in hydrophilic antioxidants (ascorbate and glutathione) and the carotenoid pool, an increase in the content of a -tocopherol, and a night retention of de-epoxidised xanthophylls (antheraxanthin and zeaxanthin). The accumulation of these xanthophylls correlated with a sustained decrease in maximal photochemical efficiency (Fv/Fm). This reduction in the rate of electron transport would reduce the production of superoxide in photosystem I, as well as the subsequent hydrogen peroxide and hydroxyl radical. Thereby if any transitory photooxidative stress is produced under these conditions it should be due mainly to the formation of singlet oxygen by triplet excited chlorophyll within the antenna. Since a-tocopherol is the main scavenger of singlet oxygen and lipid peroxy radicals, the large increase of this antioxidant within the species could be enough to compensate for the higher degree of photooxidative stress, playing an essential role in the survival of vegetation during the incidence of exceptional cold fronts in the Mediterranean region.
Keywords: a-tocopherol; antioxidants; photooxidative stress; xanthophyll cycle

Population structure of the wild boar (Sus scrofa) in two Mediterranean habitats in the western Iberian Peninsula - Fernandez-Llario, P.; Mateos-Quesada, P. (FOLIA ZOOLOGICA, 2003)
Wild boar population structure was studied in two well-preserved forests of western Iberian Peninsula, one located in a typically Mediterranean zone (vegetation mainly holm oak Quercus ilex and various tall-shrubs species), and the other in a more Atlantic area (mainly oak Q. pyrenica but with abundant cork oak Q. suber in some places). Data were colleted during hunts in monterias' area between the 1994/95 and 2000/2001 hunting seasons (October to February). 972 hunted wild boars were sexed and aged in the field, using growth patterns and tooth attrition. The mean age of hunted wild boars differed in the two zones. 2.11 years old in holm oak forest, and 1.78 years old in oak forest. This difference may result from shurb cover density and its effect on hunting dog, efficiency in rooting out wild boar. However, mean age was similar other zones of Europe. Proportionately more females were taken than males demonstrate the usefulness of Mediterranean hunting in contributing to management and conservation.
The following values have no corresponding Zotero field: pub-location: KVETNA 8, BRNO 603 65, CZECH REPUBLIC publisher: INST VERTEBRATE BIOLOGY AS CR
Keywords: age; Holm oak forest; hunting; oak forest; sex-ratio

Preferencias de los propietarios e intervención pública: el caso de las dehesas de la comarca de Monfragüe - Campos Palacín, P.; Mariscal Lorente, P. J. (Investigación Agraria: Sistemas y Recursos Forestales, 2003)
The public have an increasing interest in Dehesa environmental services (recreation, option and existence values). The growing Government incentives on environmental friendly agricultural practices have given a new opportunity for private economics of natural and environmental resources in Dehesa. This work presents the results from a Delphi questionnaire on owners’ preferences and demands of compensations for undertaking environmental conservation and improvement measures in Dehesa of Monfragüe shire. The private owners of Dehesa are investors that have, at the same time, commercial aims and private environmental services autoconsumption preferences. A contingent valuation questionnaire has been applied to a group of Dehesa ’ owners to measure the maximum willingness to pay (WTP) —to accept losses— of commercial capital income against the maintenance of private environmental services autoconsumption. The Delphi results show that owners’attitude is in favour to follow the environmental friendly agricultural practices, when the Government incentives are higher than the losses of commercial capital income plus a risk premium. The value of owners’ autoconsumption measured by the WTP question from the contingent valuation gives an autoconsumption profitability rate from 1% to 5% of the total market value of the Dehesa.
Keywords: Contingent valuation; Dehesa; Delphi technique; environmental and agroforestry practices; environmental autoconsumption services; Hicksian income

Primo contributo alla definizione tipologica delle sugherete della Calabria - Mercurio, R.; Spampinato, G. (SISEF Atti 3, 2003)
Recenti indagini sulla distribuzione della sughera in Calabria, sia sulla base dei popolarnenti esistenti che dei fitonimi , mostrano un areale poten ziale molto pill ampio di quello reale. Le cause della rarcfa zione della sughera sono dovute essenzialmenre al fuoco , al pascolo incontrollato calla manean za di interesse selvicolturale e di utilizzo del sughero. Sono rari i popo lamenti accorpati superiori a 10 ettari, mentre preval gono nuclei piu 0 meno ampi di pochi ettari 0 gruppi sparsi di poche piante. La sughera esostanzialrnentc presentc nel versante tirrenico dal livello del marc fino a circa 800 m rna si riscontra, in nuclei di piu limitata estensionc, anche in quello ionico dove in passato veniva ignorata. DOli punto di vista ecologico [a sughera si rinviene principalmente su substrati acid i quali sabbie silicee e prodotti di sfaldamento dei graniti , in aree caratterizzate da un bioclima meso mediterraneo sub umido 0 umido. DOli punta di vista fitosociologico Ie sugherete calabresi sono stale riferite all' Helleboro-Quercetum suberis, fitocenosi inclusa nelle formazioni scmpreverdi dei Quercetea ilicis . Sulla base di queste indagini vengono proposte nuov c linita tipologiche forestali : sugherete mesotile, sugherete mesotermofile c sugheretc tcrrnoxerofile. Per ogni unita tipologica vengono indicate Ie pratiche sclvicolturali piu appropriate per la loro conservazione .
The following values have no corresponding Zotero field: periodical: SISEF Atti 3
Keywords: calabria; fitosociologia; quercus silber l; tipi forestali

Regional differences in land use affect population performance of the threatened insectivorous plant Drosophyllum lusitanicum (Droseraceae) - Garrido, B.; Hampe, A.; MARAÑON, T.; Arroyo, J. (Diversity and Distributions, 2003)
We analyse populations of the insectivorous plant Drosophyllum lusitanicum (L.) Link (Droseraceae) and their habitats throughout the species’ distribution range (Portugal, Spain and Morocco), and examine their relations. We have surveyed 32 populations and we analyse their demographic structures, accompanying plant communities (by TWINSPAN analyses), and relationships between population features and several edaphic and nonedaphic environmental variables (by multiple regression analyses). Plant communities, their ﬂoristic richness and degree of endemism change across the geographical range of Drosophyllum. Populations vary strongly in size, density and age structure. Their recruitment seems largely determined by competition with the surrounding vegetation, while only weak relationships were detected between population performance and other environmental factors. The demographic structure of populations exhibits a marked geographical differentiation, with populations becoming older and sparser towards the north-western part of the range. The largest and presumably most stable populations are mostly found in southern Spanish heathlands, which are nowadays scarcely affected by man. Moroccan populations suffer from browsing by cattle and experience an accelerated generation turnover, while most Portuguese populations occur in afforested areas and experience strongly reduced recruitment. The historical distribution range of Drosophyllum within its peculiar habitat has probably been relatively stable, but recent regional differences in human land use have resulted in present-day differences in population performance, as well as in types and degrees of threat across the three countries involved. Conservation strategies should take into account this range-wide variation and combine approaches on different spatial scales.
Keywords: carnivorous plant; conservation; demographic structure; ecogeography; geographical range; mediterranean heathland; range-wide survey; Regeneration

Runoff erosion and nutrient depletion in five Mediterranean soils of NE Spain under different land use. - Pardini, Giovanni; Gispert, Maria; Dunjó, Gemma (The Science of the total environment, 2003)
We investigated the influence of agricultural management and various plant covers related to the period of abandonment on soil properties, erosion and nutrient depletion in a typical Mediterranean area with sandy loam shallow soils. Cultivated soils (CS) with insufficient management, 5 year abandoned soils covered with meadow (A5), 25 year abandoned soils covered with dense scrubs (A25), 50 year abandoned soils covered with cork trees (A50) and soils in a 50 year pine reforested area (P50) were studied over a period of 6 months (May-October 1999). The soils were classified as Lithic Xerorthents. Both the differences in soil properties and response to rainfall events were mainly attributed to the different vegetation types and stages in land management. Principal components analysis (PCA) was performed on the results, by running the overall data determined after five rainfall events. The factors extracted by PCA of the samples by variables matrix represented the response of the environments to different rainfall intensities as a function of management or natural evolution after abandonment. CS environments showed the highest runoff and sediment yield as well as the highest amount of dissolved organic carbon (DOC) and nitrogen in runoff water. The sequence of abandonment (A5, A25 and A50) showed approximately the same runoff production, whereas eroded sediments (ES) and DOC were inversely correlated. Organic carbon in the ES and DOC in runoff water always increased with the period of abandonment, which accounted for consistent nutrient depletion. Nevertheless, the A50 environment (dominated by Quercus suber) showed the best soil properties, whilst the A25 environment with dense cover of Cistus monspeliensis and Calicotome espinosa seemed to cause a worsening effect on the soil's physical and chemical properties. This is probably because these environments are more severely damaged by wild fire occurrence. In terms of sediment yield, the P50 environment followed CS environment, indicating that reforestation followed by insufficient forest management may negatively affect both soil properties and response to the erosive action of rainfall.
The following values have no corresponding Zotero field: accession-num: 12798105
Keywords: Abandonment; erosion; land management; nutrient availability; Nutrient losses; runoff; Sediment yield; soil properties; structure; Water retention

Silvicultural management in maintaining biodiversity and resistance of forests in Europe—the Mediterranean region - Fabbio, Gianfranco; Merlo, Maurizio; Tosi, Vittorio (Journal of Environmental Management, 2003)
Outstanding features of Mediterranean forest area are highlighted with a special reference to biodiversity and connections with forest management. The naturally originated and anthropogenic progress of the mosaic-like evolution, as well as the man-induced factors and natural constraints are described. The past and present close linkages between management and biodiversity are then analysed by means of a few, outstanding cases typical of the geographical region. The management shift on increasing economically marginal forest area (abandonment) appears to be the major force currently driving connections with inherent and associated biodiversity. The goals following the new-established environmental roles of forests have shifted towards adaptive management, namely the implementation of locally tailored rules in accordance with prominent forest functions. Key priorities to face up to the new scenarios are then discussed. Economic and policy implications are addressed with reference to multipurpose forestry and the related annual ﬂow of outputs. It is shown the role of water-related services, as well the provision of various non-wood forest products and public goods in addition to wood and other traditional forest outputs. Reference is also made to the dualism between the Northern and the South-Eastern Mediterranean countries due to different level of economic development (and pressure of forest resources) together with very different institutional structures, i.e. public ownership in Southern and South-Eastern Mediterranean countries. Nevertheless, the situation is going to become more harmonious in the medium run by growing economic development, the afﬁrmation of local rights on forest resources, globalisation and, above all, rural out migration and exchanges of peoples conﬁrming the traditional role of the Mediterranean Region at cross road of South–North and Eastern– Western cultures.
Keywords: Adaptive management; Biodiversity; economic and policy implications; Mediterranean Region; multipurpose role of forests; silvicultural management

Soil persistence and biodiversity of ericoid mycorrhizal fungi in the absence of the host plant in a Mediterranean ecosystem. - Bergero, Roberta; Girlanda, Mariangela; Bello, Federica; Luppi, Anna Maria; Perotto, Silvia (Mycorrhiza, 2003)
The occurrence of suitable mycorrhizal inocula may be an important factor affecting the dynamics of plant communities. We investigated the persistence and diversity of ericoid mycorrhizal fungi in the soil of a mature Quercus ilex forest where ericaceous hosts were absent. Erica arborea was used as a bait plant and results were compared to soil samples from experimental plots where cuttings had allowed reappearance of this ericaceous species. Fungal endophytes were isolated and tested in mycorrhiza resynthesis trials. Sterile mycorrhizal endophytes were assigned to morphotypes whose consistency was confirmed by ITS-RFLP. The ITS region of a representative of each morphotype was sequenced. BLAST searches and Neighbour-Joining analysis indicated taxonomic affinities with different classes within Ascomycota. Our results indicate that ericoid mycorrhizal fungi persist and maintain mycorrhizal ability in habitats lacking the ericaceous host. Their persistence could favour the establishment of E. arborea seedlings in pure Q. ilex forests after disturbance phenomena.
The following values have no corresponding Zotero field: accession-num: 12682828
Keywords: Erica arborea; Mediterranean ecosystem; Plant succession; Post-cutting; Quercus ilex

Soil seed bank and floristic diversity in a forest-grassland mosaic in southern Spain - Díaz-Villa, M. D.; MARAÑON, T.; Arroyo, J.; Garrido, B. (Journal of Vegetation Science, 2003)
Soil seed bank and floristic diversity were studied in a forest of Quercus suber, a forest of Quercus canariensis and a grassland, forming a vegetation mosaic in Los Alcornocales Natural Park, southern Spain. The soil seed bank was estimated by the germination technique. In each community patch, diversity, woody species cover and herbaceous species frequency was measured. Three biodiversity components – species richness, endemism and taxonomic singularity – were considered in the vegetation and the seed bank. Forest patches had a soil seed bank of ca. 11 200-14 100 seed.m–2 and their composition had low resemblance to (epigeal) vegetation. The grassland patch had a more dense seed bank (ca. 31 800 seed.m–2 ) and a higher index of similarity with vegetation, compared with the forests nearby. The complete forest diversity was 71-78 species on 0.1 ha, including 12-15 species found only in the seed bank; the grassland species richness was higher (113 species on 0.1 ha). We discuss the role of soil seed banks in the vegetation dynamics and in the complete plant biodiversity of the mosaic landscape studied.
Keywords: Biodiversity; forests conservation; mediterranean forest; nomenclature; Regeneration; Species richness

The study of reactions influencing the biomass steam gasification process - Franco, C.; Pinto, F.; Gulyurtlu, I.; Cabrita, I. (FUEL, 2003)
Steam gasification studies were carried out in an atmospheric fluidised bed. The gasifier was operated over a temperature range of 700900 degreesC whilst varying a steam/biomass ratio from 0.4 to 0.85 w/w. Three types of forestry biomass were studied: Pinus pinaster (softwood), Eucalyptus globulus and holm-oak (hardwood). The energy conversion, gas composition, higher heating value and gas yields were determined and correlated with temperature, steam/biomass ratio, and species of biomass used. The results obtained seemed to suggest that the operating conditions were optimised for a gasification temperature around 830 degreesC and a steam/biomass ratio of 0.6-0.7 w/w, because a gas richer in hydrogen and poorer in hydrocarbons and tars was produced. These conditions also favoured greater energy and carbon conversions, as well the gas yield. The main objective of the present work was to determine what reactions were dominant within the operation limits of experimental parameters studied and what was the effect of biomass type on the gasification process. As biomass wastes usually have a problem of availability because of seasonal variations, this work analysed the possibility of replacing one biomass species by another, without altering the gas quality obtained. (C) 2002 Elsevier Science Ltd. All rights reserved.
The following values have no corresponding Zotero field: pub-location: THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND publisher: ELSEVIER SCI LTD
Keywords: biomass; fluidised bed; gasification; steam

Thermal optima of photosynthetic functions and thermostability of photochemistry in cork oak seedlings - Ghouil, Hana; Montpied, Pierre; Epron, Daniel; Ksontini, Mustapha; Hanchi, Belkacem; Dreyer, Erwin (Tree Physiology, 2003)
Temperature effects on photosynthesis were studied in seedlings of evergreen Mediterranean cork oak (Quercus suber L.). Responses to changes in temperature and the temperature optima of maximal carboxylation rate (Vcmax) and maximal light-driven electron flux (Jmax) were estimated from gas exchange measurements and a leaf-level photosynthesis model. The estimated temperature optima were approximately 34 and 33 °C for Vcmax and Jmax, respectively, which fall within the lower range of temperature optima previously observed in deciduous tree species. The thermostability of the photosynthetic apparatus was estimated according to the temperature at which basal chlorophyll a fluorescence begins to increase (Tc). The Tc was highly variable, increasing from 42 to 51 °C when ambient temperature rose from 10 to 40 °C, and increasing from 44 to 54 °C with decreasing soil water availability while net CO2 assimilation rate dropped to almost zero. When a heat shock was imposed, an additional small increase in Tc was observed in drought-stressed and control seedlings. Maximal Tc values following heat shock were about 56 °C, which, to our knowledge, are the highest values that have been observed in tree species. In conclusion, the intrinsic temperature responses of cork oak did not differ from those of other species (similar Tc under ambient temperature and water availability, and relatively low thermal optima for photosynthetic capacity in seedlings grown at cool temperatures). However, the large ability of cork oak to acclimate to drought and elevated temperature may be an important factor in the tolerance of this evergreen Mediterranean species to summer drought and high temperatures.
10.1093/treephys/23.15.103110.1093/treephys/23.15.1031
Keywords: chlorophyll fluorescence; Gas exchange; maximal carboxylation rate; maximal light-driven electron flow; Regeneration

Thinning effects on carbon allocation to fine roots in a Quercus ilex forest - López, B. C.; Sabate, S.; Gracia, C. A. (Tree Physiology, 2003)
The dynamics of the fine root system are relevant to calculations of the carbon balance of the ecosystem, and there is also a need to quantify changes in this component caused by disturbances. Mediterranean forest systems have historically been coppiced to obtain charcoal. As a result of the resprouting capacity of holm oaks (Quercus ilex L.), these forests present more than 50% of their biomass below ground (stump + roots > 1 cm in diameter), but the effects of thinning on the fine root system are unknown. Fine root biomass, production, mortality and longevity were studied in a control and a thinned Mediterranean holm oak forest by minirhizotron methodology. Observations of fine roots started 2 years after thinning and continued for almost 3 years. Extraction of 80% of the former basal area of the forest greatly affected carbon allocation patterns. Biomass increased by more than 100%, production increased by 76%, mortality increased by 32% and longevity decreased by around 2 weeks. The greatest differences between treatments were associated with differences in growth during autumn months in the top 40 cm of soil, particularly between 10 and 20 cm depth.
10.1093/treephys/23.17.121710.1093/treephys/23.17.1217
Keywords: biomass; longevity; mortality; production

Time budget and habitat use of the Common Crane wintering in dehesas of southwestern Spain - Avilés, Jesus M. (Canadian Journal of Zoology, 2003)
In many bird species juvenile inexperience drastically reduces their survival, and parents must provide for them. I tested whether time budget and habitat use in adult wintering Common Cranes (Grus grus) in dehesas (pastoral woodland) of western Spain were affected by the presence of juveniles. Juvenile cranes devote less time to vigilance and spend more time feeding than adults in dehesas. Likewise, juveniles are involved in fewer aggressive encounters than adult cranes. Contrary to expectation, adults accompanied by juveniles devoted the same amount of time to vigilance and feeding and had the same intake rate than adults without juveniles in attendance. However, adult cranes with offspring in attendance were involved in more aggressive encounters than adults without juveniles in attendance when both adult groups were involved in large flocks. In contrast, when adults accompanied by juveniles were in small flocks they were involved in fewer aggressive encounters than adults without juveniles. I also detected a differential use of dehesas by adult cranes that was linked to juvenile presence and explained by the vulnerability of juvenile cranes in intraspecific social relationships. Adults with juveniles in attendance preferred dehesas with livestock where flock sizes were smaller than those in dehesas without livestock, and therefore where they might reduce the number of aggressive encounters with other cranes.
doi: 10.1139/z03-105doi: 10.1139/z03-105The following values have no corresponding Zotero field: publisher: NRC Research Press
Keywords: Cranes; Dehesa; feeding (voyant); intake rate; livestock; parental investment; social structure

Total antioxidant activity in Quercus ilex resprouts after fire - El Omari, Bouchra; Fleck, Isabel; Aranda, Xavier; Abadía, Anunciación; Cano, Antonio; Arnao, Marino B. (Plant Physiology and Biochemistry, 2003)
After ﬁre, holm oak (Quercus ilex L.) resprouts have a higher light availability and photosynthetic activity than control plants in intact vegetation. To assess the differences in protection between these plants, we determined, in two forests, changes in gas-exchange rates, chlorophyll ﬂuorescence parameters, chloroplast pigment content and total antioxidant activity (TAA) in different seasons, at different times of the day and in relation to leaf age. The end-point method used for TAA determination allowed the evaluation of the relative contribution of hydrophilic and lipophilic antioxidants in leaf extracts. High correlations were obtained between lipophilic TAA and certain chloroplast pigment content, the highest contribution being provided by b-carotene and the components of the xanthophyll cycle (zeaxanthin + antheraxanthin, violaxanthin). All leaves showed a much higher contribution (94–99%) of hydrophilic than lipophilic antioxidants to TAA. In summer, at midday, photosynthetic rates and TAA were higher in resprouts. In these plants, reduced xanthophyll-cycle participation (as shown by non-photochemical quenching (NPQ) and xanthophyll pool content) was compensated by an increased participation of hydrophilic antioxidants. No effect of time of day or plant age was observed. The results suggest that energy dissipation as heat, and detoxiﬁcation mechanisms contribute to the protective strategies of control plants and resprouts, albeit to a different extent.
Keywords: carotenoids; non-photochemical quenching; Quercus ilex; reactive oxygen species; Resprouts; total antioxidant activity

Adaptive strategy at the leaf level of Arbutus unedo L. to cope with Mediterranean climate - Gratani, Loretta; Ghia, Emanuela (Flora-Morphology, Distribution, Functional Ecology of …, 2002)
The adaptive strategy of Arbutus unedo L. under Mediterranean climate seemed to be due to the high leaf area (LA = 11.1 ± 0.1 cm2 ) increasing the potential capacity of light interception, the high leaf lamina thickness (L = 395 ± 10 µm) increasing the potential capacity for gas exchange, and the steeper leaf inclination at midday (α up to 63.9 ± 0.3°) determining 48% of reduction of incident radiation on a sloping leaf surface (RI), which could be a prevention mechanism against the potential photoinhibition of water-stressed leaves during drought. Nevertheless, during the drought period the photosynthetic activity and the water use efficiency (WUE) of A. unedo were strongly reduced (≥ than 50% of the maximum). Principal component analysis (PCA) underlined the higher similarity of A. unedo and Quercus ilex L. from a physiological point of view (photosynthetic rates PN , transpiration rates E, stomatal conductance gs , sub-stomatal CO2 concentration Ci ) and for leaf inclination, and with Cistus incanus L. from a phenological (leaf-life span) and structural point of view (specific leaf area SLA and leaf tissue density LTD), for leaf temperature (Tl ) and for leaf water status (leaf water potential at midday Ψmin and relative water content RWC). Therefore A. unedo might be considered in the borderline between drought semi-deciduous species and evergreen sclerophyllous species.
Keywords: Gas exchange; leaf area; leaf inclination; leaf lamina thickness; leaf-life span; sclerophylly

Amino acid availability and energy value of acorn in the Iberian pig - Aguilera, J. F.; Nieto, R.; Rivera, M.; Garcıa, M. A. (Livestock Production Science, 2002)
Two experiments have been performed to determine amino acid digestibility and energy value of acorn (Quercus rotundifolia L.) for Iberian pigs. In experiment 1 ileal digestibility of amino acids was determined in ﬁve ileum-cannulated growing pigs fed whole ground acorn. An estimation of endogenous protein losses was carried out by feeding a protein-free diet, added (180 g/kg) or not with acorn hulls. True ileal digestibility of all essential amino acids measured was high (0.798–1.03) except for arginine (0.523), lysine (0.601), isoleucine (0.760), leucine (0.777) and phenylalanine (0.716). The average value for the digestibility of the sum of amino acids was 0.664. Lysine was the ﬁrst limiting amino acid compared with the amino acid proﬁle of the ideal protein for pigs. In experiment 2, total tract digestibility of nutrients and N balance were determined in ﬁve, non-cannulated pigs offered whole acorns. High coefﬁcients for the apparent total tract digestibility of dry matter (ApDM) (0.830) and energy metabolizability (ME/GE; 0.805) were found. ME content for acorn kernel was 16.6 MJ/kg DM, while the apparent total tract digestibility of total N (ApTN) was as low as 0.408. However, a positive N retention was observed (3.7 g/day). Comparing experiments 1 vs. 2, inclusion of acorn hulls resulted in a marked decrease in DM intake, ApTN and in N retention (25.1 g/day, in total tract data from experiment 1). The negative effects of acorn hulls on protein digestibility and N balance were corroborated in rats given similar amounts of either whole ground acorn or ground acorn kernel. Dietary supplementation with lysine is proposed to achieve a higher efﬁciency of protein accretion in the Iberian pig when fed on acorn.
Keywords: acorn; amino acids; energy value; pig-feeding and nutrition; protein quality

Análise da Estratégia Fenodinâmica de Cistus salvifolius em Três Locais Distintos (Pinhal de Leiria, Cabeção e Odemira) - Borges, Ana Eleonora; de Almeida, Victor Valente; da Silva, António Morais (Silva Lusitana, 2002)
We describe the phenomorphological strategy of Cistus salvifolius found in pine woods of the Leiria region and in cork oak woodlands of Alentejo (Cabeção and Odemira north and Odemira south). An analysis is made of the evolution of the biological cycle as a function of climatic changes
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: ecomorphology; edaphic factors; Phenology; srubs; underground

Annual feeding rate of the millipede Glomeris marginata on holm oak ( Quercus ilex) leaf litter under Mediterranean conditions - DAVID, J. F.; Gillon, Dominique (Pedobiologia, 2002)
The annual consumption and assimilation rates of Quercus ilex leaf litter by the millipede Glomeris marginata were estimated under Mediterranean conditions simulated in the laboratory. Measurements were made on six occasions throughout the year to take into account seasonal variations in (i) the quality of decomposing leaves, (ii) the physiological state of the animals, and (iii) temperature plus photoperiod. The mean weight-specific consumption rate was 14 g (dry weight) g-1 (live weight) y-1 , which is much higher than published figures for Mediterranean oak leaf litter. The consumption rate was highest in spring (51 mg g-1 d-1 ) and lowest in summer (28 mg g-1 d-1 ), the summer consumption rate being even lower when determined with air-dried leaves (17 mg g-1 d-1 ). Assimilation efficiency averaged 6 % for the year, with a maximum in spring (9 %) and a minimum in winter (1 %). A much higher assimilation efficiency (29 %) was measured with freshly fallen leaves, but a food preference experiment showed that these leaves were generally avoided and that G. marginata preferred more decomposed leaves despite their lower digestibility. It is concluded that these saprophagous macroarthropods – with field biomasses of 7–11 g (live weight) m-2 – produce considerable amounts of faecal pellets in Mediterranean oak forests.
Keywords: assimilation efficiency; diplopoda; feeding rate; Mediterranean forests; soil macrofauna

Ascertaining Landscape Perceptions and Preferences with Pair-wise Photographs: Planning rural tourism in Extremadura, Spain - García Pérez, Joséd (Landscape Research, 2002)
Making use of available resources in the most efficient way is a fundamental principle of all development strategies. Landscapes are an abundant natural resource and form an important basis for the tourism industry. The case of rural Extremadura is considered for its potentially important landscape and growing rural tourist sector. A method of landscape analysis based on pair-wise comparison of photographs is used to ascertain the landscape preferences for rambling of tourists in rural areas. Their preferences are analysed according to personal characteristics and holiday activities. It is concluded that the identification of preferences can be of considerable value in the planning of ramblers' routes for specific social groups.
doi: 10.1080/01426390220149539doi: 10.1080/01426390220149539The following values have no corresponding Zotero field: publisher: Routledge
Keywords: Extremadura; landscape assessment; pair-wise analysis; planning; ramblers; tourism

Aspectos económicos de las prácticas agroforestales: un sistema de indicadores monetarios y biofísicos - Campos Palacín, P.; Rodríguez Luengo, Y. (Cuadernos de la Sociedad Española de Ciencias Forestales, 2002)
Se presenta en este trabajo un sistema de Cuentas Económicas Agroforestales (CAF) que tiene como objetivos principales el cálculo de la renta total sustentable desagregada por aprovechamien- tos y la aportación de un grupo seleccionado de indicadores biofísicos del uso múltiple de los recur- sos naturales y ambientales de una tierra. La metodología CAF es desarrollada al hilo de su aplica- ción a una dehesa de la comarca de Monfragüe en el ejercicio contable del año 1997
Keywords: autoconsumo ambiental; cuentas agroforestales; Dehesa; renta total

Assessment of the use of n-alkanes as markers to describe the complex diets of herbivores - Martins, H.; Elston, D. A.; Mayes, R. W.; Milne, J. A. (JOURNAL OF AGRICULTURAL SCIENCE, 2002)
Previous approaches to the description of complex diets, based on n-alkanes and optimization techniques, have grouped the plant species to reduce the number of components. Diet estimates have been obtained with least-squares routines by minimizing the discrepancy between faecal alkane concentrations calculated from herbage concentrations and actual faecal alkane concentrations. The effect of diet selection within groups can only be assessed by using sensitivity tests or by giving subjective weights to the individual plants. In the current study, a new optimization algorithm was developed that selects weightings that lead to consistent estimates of group proportions. The diet of the wild rabbit in a southern Portuguese montado was used as a case study. Estimates of the diet composition obtained using the new algorithm were compared with those of a conventional routine. The new algorithm was shown to provide, on average, more accurate estimates of the proportions of the groups in the diet. The effect of grouping plant species according to criteria other than similarity in n-alkane pattern on the accuracy of estimates was shown to be non-significant.
The following values have no corresponding Zotero field: pub-location: 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA publisher: CAMBRIDGE UNIV PRESS

Biomonitoring of Atmospheric PAHs by Evergreen Plants: Correlations and Applicability - Librando, V.; Perrini, G.; Tomasello, M. (Polycyclic Aromatic Compounds, 2002)
This article deals with looking for the best passive samplers among eleven plants diffused in the Mediterranean basin for the determination of polycyclic aromatic hydrocarbons in the atmosphere in substitution to the particulate matter sampling. The most recent research about biological passive samplers showed a quali-quantitative difference in pollutant sampling by different plants. Evergreen trees with long-lived leaves were selected in the urban area of Catania (Italy) and both samples (leaves and particulate matter) were extracted and purified by a two stage method before the analysis was performed by a GC/MS. Leaves and particulate matter were sampled in three different seasons (winter, spring and summer). PAHs concentrations found in the particulate matter and leaves were correlated. Some plants ( Olea europaea and Quercus ilex ) showed high values (r 2 > 0.85) of linear correlation coefficient in all seasons and are characterized by profiles similar to that of the particulate matter. Further, it has been observed that during the warmer seasons the total quantity of PAH adsorbed by the plants is greater but the fitting is better during winter. No difference was found by washing leaves with distilled water: this means that PAHs aren't deposited on the surface but are adsorbed in the lipidic layer of the leaves.
doi: 10.1080/10406630213563doi: 10.1080/10406630213563The following values have no corresponding Zotero field: publisher: Taylor & Francis
Keywords: correlation; GC/MS; leaves; PAH; particulate matter; passive samplers

Climatic changes since the Late-glacial/Holocene transition in La Mancha Plain (South-central Iberian Peninsula, Spain) and their incidence on Las Tablas de Daimiel - Dorado, Miriam; Rodr, Ana Valdeolmillos; Zapata, M. Blanca Ruiz; Jos, M.; Garc, Gil; Bustamante, Irene De (Quaternary International, 2002)
A palynological and lithological continuous record from La Mancha Plain (South-central Iberian Peninsula, Spain) is presented. The obtained results have permitted the reconstruction of the climatic evolution in the area since the Late-glacial/Holocene transition. The end of the Late-glacial was characterized by a cold and arid climate and it concluded at about 98907180 yr BP. In the Early Holocene a slight climatic amelioration began, being interrupted by a more arid phase around 8500 yr BP. The Holocene Climatic Optimum started from ca. 8000 yr BP and was characterized by higher temperatures and more humidity. During the MidHolocene–Late Holocene times a stage of marked aridity occurred towards 5000 yr BP that preceded the development of a dry mediterranean climate. Under this new climate a short-time arid phase took place around 2500 yr BP after which the mediterranean conditions became accentuated, with an increasing dry climate. This climatic evolution has affected the characteristics of the marshlands of Las Tablas de Daimiel National Park, originating changes in the sedimentary environment. This environment was mainly ﬂuvial until the end of the Holocene Climatic Optimum and became lacustrine–palustrine from the beginning of the more arid conditions.
Keywords: arid phase; Climatic conditions; Evergreen and deciduous species (voyant); Holocene; Pollen analysis; Quercus; Spain

Composition and chemical variability of the triterpene fraction of dichloromethane extracts of cork (Quercus suber L.) - Castola, Vincent; Bighelli, Ange; Rezzi, Serge; Melloni, Giovanni; Gladiali, Serafino; Desjobert, Jean-Marie; Casanova, Joseph (Industrial Crops and Products, 2002)
Dichloromethane extracts were prepared from 38 samples of cork harvested in different locations of Corsica and Sardinia from individual trees of Quercus suber L. Friedelin, 3--hydroxyfriedelan-2-one, betulin, betulinic acid, -sitosterol and sitost-4-en-3-one were identiﬁed and their molar percentages were calculated by 13 C NMR spectroscopy, following a procedure recently developed by our group. The results were submitted to chemometric analysis (k-means and principal component analysis), which allowed three groups to be distinguished with respect to the content of friedelin, betulinic acid and 3--hydroxyfriedelan-2-one.
Keywords: 13C NMR; Chemical variability; Chemometric analysis; Cork; extracts

Copper(II) and nickel(II) uptake from aqueous solutions by cork wastes: a NMR and potentiometric study - Villaescusa, Isabel; Fiol, Núria; Cristiani, Franco; Floris, Costantino; Lai, Simona; Nurchi, Valeria Marina (Polyhedron, 2002)
Due to the increasing interest in the use of biomasses from agriculture as removing agents for heavy metals in waste effluents, we present here a joint potentiometric and 13C MAS and cross polarization-magic angle spinning NMR (CP-MAS NMR) study on cork interaction with Cu(II) and Ni(II). Through potentiometry we were able to distinguish two kind of interactions, a stronger one which involves protonated sites on cork and a second that allows hydroxide precipitation of the bound metal ion into the cork structure. NMR signal analysis suggests a specific metal complexation on the carbohydrate moieties of polymeric cork matrix. The 13C MAS NMR suggests that the dynamics in the MHz range and the overall arrangement of polymeric matrix is not affected by metal binding; and the spin relaxation times T1ρ(1H) and T1ρ(13C) show that no significant difference of relaxation processes in the KHz range is introduced by metal coordination.
Keywords: copper; Cork; Metal uptake; Nickel; Potentiometric titration; Solid state 13C MAS and CP-MAS NMR

Culture in vitro des bourgeons axillaires de Chêne-liège (Quercus suber L.). I—Influence des cytokinines sur l'organogenèse et la callogenèse de nœuds de plantules - Kbiach, M. L. El; Lamarti, A.; Abdali, A.; Badoc, A. (Bull. Soc. Pharm. Bordeaux, 2002)
Le débourrement in vitro des bourgeons axillaires de plantules de Chêne-liège a été abordé. L’influence de cytokinines ou de composés à activité cytokinine, seuls ou combinés aux auxines ou à l’AG3 , sur l’induction des bourgeons, l’élongation des pousses feuillées et la formation des cals a été étudiée. Dans le milieu de culture WPM, additionné des microéléments et du mélange vitaminique MS, la BA à 4,5 µM favorise la caulogenèse. Son association à d’autres régulateurs de croissance ne permet pas une amélioration du taux de débourrement. En revanche, à 4,5 µM et combinée à 7 µM d’ANA, la callogenèse est importante.
Keywords: bourgeons axillaires; call; callogenèse (PG); chêne-liège; cytokinines; débourrement in vitro

de preferencias de hábitat y de distribución y abundancia invernal de aves en el centro de España. Análisis y predicción del efecto de factores ecológicos - Carrascal, L. M.; Palomino, D.; Lobo, J. M. (Animal Biodiversity and Conservation, 2002)
Patterns of habitat preference and distribution and abundance of wintering bird fauna in central Spain. Analysis and prediction of the effect of ecological factors.— This paper analyses the effect of geographic, topographic, land use and habitat structure variables on the composition and structure of wintering bird communities in Central Spain (Iberian peninsula). Parameters describing the avifauna varied in a predictable way considering a small group of coarse–grained variables defining the geographical and altitudinal location of the censuses, and the basic characteristics of the structure and typology of habitats: 49–76% of variance accounted for total bird density and for abundance of four ecological groups, 37–63% accounted for species richness and diversity, and 65% explained the relative abundance of species with conservation problems according to the European scale (SPEC figures). Regarding the most widespread species in the study area, significant models were obtained by means of tree regression analysis for 50 species, with an average reduction of deviance of 39%. Altitude was the most important variable affecting bird community parameters and abundance of each bird species, showing a consistent and marked negative effect. Structural complexity of the vegetation and geographical location followed as the variables of importance explaining variability. The habitats with the lowest bird density, richness and diversity of birds were mountain grasslands/shrublands, young pine re–forestations, and Pyrenean oak forests at 1,200–1,600 m a.s.l. The habitats with the highest values on these parameters were riparian forests, agricultural mosaics, and holmoak "dehesa" parklands, mainly located at the southern and western part of the region and at intermediate altitudes. The total density of birds increased from east to west, was higher in intermediate altitudes than in the extremes of the altitudinal range, and increased with habitat structural complexity (i.e., vertical development and degree of vegetation cover), agricultural use of the land, and the presence of water (e.g., streams, rivers, flooded areas). Density of strictly wintering species in the study region decreased latitudinally from southeast to northwest, being higher at intermediate altitudes in localities with presence of water and woodlands dominated by coniferous trees. Abundance of facultative or obligate frugivorous species was very low. Richness of species was higher toward the western part of the study area, increased with habitat structural complexity, and was lower at higher altitudes. On the other hand, the less diverse bird assemblages were those that inhabit agricultural landscapes and/or areas located at higher altitudes. Habitats and areas with a higher relative abundance of species with conservation problems at the European scale (SPEC scores) were located at intermediate altitudes in the southwest and southeast of the study region. The relative abundance of this group of species was also associated to the presence of water, habitat structural complexity and agricultural use. The relationship between the European conservation status of species (SPEC scores) and the patterns of distribution, abundance, habitat preferences and ecological width of 72 species was also analysed. Species with more conservation problems on the European scale have a marked preference for structurally simpler habitats (e.g., agricultural and grasslands habitats) and have a broader altitudinal and among–habitats distribution. Results from the 44 census localities were extrapolated to the remaining region using a geographical information system in order to build predictive maps for density, species richness, species diversity and weighed European conservation status. This work shows that valuable knowledge can be obtained from fragmentary and dispersed data, in order to describe general patterns of distribution, abundance and habitat preferences of birds. This methodological approach could be a valid in environmentally heterogeneous, large regions, with few qualified bird observers and researchers.
Keywords: Central Spain; Density; habitat preferences; regression models; Species richness; wintering avifauna

Distribución de especies de matorral en suelos ácidos y básicos de la Sierra de Grazalema, sur de España - Gallego Fernández, Juan Bautista (Anales del Jardín Botánico de Madrid, 2002)
The presence of Mediterranean shrubland woody species on acid or basic soils was studied at Grazalema Mountains. Transects were made at 137 sampling sites in the study área and 74 species were recognized. Phlomis purpurea. Cistus albidus. Quercus rotundifolia and Ulex baeticus were the most frequent species, being present at 70 % of the transects. Pistacia lentiscus. Rubia peregrina and Daphne gnidium were found in 50 % of the transects. From the total species recorded, 67 species were located on basic soils and 55 on acid soils; 19 species (25.7 %) were located only on basic soils and 7 species (9.5 %) only on acid soils; 21 species were significantly more frequent on basic soils, and 10 species on acid soils. The number of species per transect were significantly higher on basic soils (13.2 ± 3.8) than on acid soils (10.3 ± 3.7). Differences in species number are related to a higher number of species displaying a narrow distribution in the basic shrublands as well as due to species loss in the acid shrublands, as a consequence of geographic isolation and human disturbance.
Keywords: Betic ranges; Mediterranean shrubland; soil pH

Does temporal variability of winter Common Cranes in the dehesas depend on farming practices? - Aviles, J. M.; Medina, F. J.; Sánchez, J. M.; Parejo, D. (Waterbirds, 2002)
The inclusion of Spain and Portugal within the European Community has brought about a change in the traditional farming practices in the dehesas of Iberia to intensive cereal and to irrigated crops. Here we use seven-year counts of Common Cranes in 38 wintering sites to evaluate whether habitat structure modified by farm- ing practices in the Holm Oak (Quercus ilex) dehesas is an important determinant of variability in winter crane num- bers. We extracted, from a set of nine variables that express different levels of human management in the Holm Oak dehesas, two factors that accounted for the 66% of the variance. The first factor was related to livestock utiliza- tion of the dehesas, while the second one reflected Holm Oak presence. We ran a general linear model to analyze the influence of farming practices (PC1 and PC2), landscape heterogeneity and roost site stability on inter- and in- tra-season variability in numbers of winter cranes. Livestock presence, Holm Oak presence, landscape heterogeneity and roost type stability did not explain intra- and inter- season variability in crane numbers wintering in the Holm Oak dehesas of Spain.
Keywords: Agricultural intensification; Common Crane; Grus grus; holm oak dehesas; southwestern Spain; winter stability

Drosophyllum lusitanicum, an endangered West Mediterranean endemic carnivorous plant: threats and its ability to control available resources - Correia, E.; Freitas, H. (BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, 2002)
Drosophyllum lusitanicum (L.) Link (Droseraceae), Erva pinheira orvalhada, an endangered carnivorous plant, is a local endemic of clearings in pine, cork oak and oak forests or their successional shrublands in the western Iberian Peninsula and Morocco. The conservation status, distribution and population dynamics of this species are only partially known, both for Spanish and Portuguese occurrences. Portuguese distribution data from herbarium and bibliographic sources were collected for this study. Field work on 50 populations was undertaken in order to improve knowledge on their conservation status and possible threats. Natural causes, infrastructure and housing construction are stressed as the most important threats. Germination tests were carried out and the distribution patterns, plant height and the number of flowers were studied in an arbitrarily chosen population. A relatively high light requirement and low competitive ability to gain light are considered factors likely for the microdistribution pattern. Drosophyllum lusitanicum cannot compete for light in habitats with intense competition. Seeds from D. lusitanicum have reduced probability of germination when adult plants are already growing in the area. It is hypothesized that seed germination shows a similar pattern to flowering, viz over a considerable time rather than in a sudden flush. This strategy may be a key factor for the species' survival, representing attempts to take advantage of available resources, preventing intraspecific competition and, finally, preventing sudden total disappearance of a population, resulting from any catastrophic events due to natural causes or to human activity. As a result of this study, some conservation measures are suggested. (C) The Linnean Society of London.
The following values have no corresponding Zotero field: pub-location: 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND publisher: ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD
Keywords: competition; competitive ability; Droseraceae; intraspecific competition; microdistribution pattern; Portugal; seed bank

Endoglucanase and β-glycosidase activities in an evergreen oak litter: annual variation and regulating factors - Criquet, S.; Tagger, S.; Vogt, G.; Le petit, J. (Soil Biology and Biochemistry, 2002)
This paper represents the third part of a larger study about the processes involved in litter biodegradation in an oak copse in France. It concerns the variations in activities of endoglucanases and of β-glycosidases over 13 months in forest litter. Evergreen oak (Quercus ilex L.) litter was taken as a model because Q. ilex is the most abundant tree species in forests of the French Mediterranean area. The activities of several endoglucanases and β-glycosidases, and the concentrations of the proteins and reducing sugars were measured in the evergreen oak litter between October 1997 and October 1998. Several biotic and abiotic factors, potentially involved in the regulation of the activities of these hydrolyzing enzymes, were also measured: culturable heterotrophic bacteria, cellulolytic bacteria and cellulolytic fungi, moisture, temperature and pH of the litter. Under this Mediterranean climate, the moisture of the litter was strongly correlated with many factors and is likely to be important in regulating the temporal dynamics of various biological parameters. A multiple regression analysis showed that the annual dynamic of the culturable heterotrophic bacteria was primarily influenced by moisture but also by variations in concentration of reducing sugars in the litter. Moreover, these bacteria were correlated with the activities of several β-glycosidases, and specifically with the N-acetyl-glucosaminidases (r=0.93). No relationships were established between the number of cellulolytic microorganisms (bacteria and fungi) and the activities of endoglucanases (i.e. cellulases and hemicellulases). The seasonal trends of certain biotic processes, and the influence of pH and of temperature on these processes are also discussed. Electrophoretic analyses were used to estimate the number of cellulase and xylanase isoenzymes in the litter, and to study their fluctuations over one year. The prevailing cellulase isoenzyme had a Rf of 0.64, and there was no relationship between the abundance of cellulolytic microorganisms and the electrophoretic profiles of the cellulases. In the case of the xylanases, the electrophoretic profiles were homogenous throughout the year, and the prevailing xylanase had a Rf of 0.75.
Keywords: Cellulase; hemicellulase; Isoenzymes; litter; Polysaccharides

Estudio de la variabilidad temporal y espacial de la pérdida de suelo en la dehesa (Extremadura, SO España) mediante lluvia simulada - Ceballos Barbancho, A.; Shanabel, S.; Cerdà, A. (Geographicalia, 2002)
The inain objective of this paper is to study the influence of the seasonal variability of tlze antecedent conditions in soil losses in a dehesa ecosystem, as well as an approach to its spatial variability. The experimental layout includes forty rainfall simulation experiments carried out in two different situa- tions: first on dry conditions, with degraded vegetation, and, second on wet con- ditions, with an important vegetation cover. The results indicate that the highest sediiilent concentrations are located in situations with bare soils, due to the effect of the drought and the soil remo- ved by grazing animals. The control of the process depends more to tlie sediment available on the soil surface than to the runoff transport capacity. From an spatial point of view, it liighlights the contrast between tlie low los- ses registered in the valley bottoms and the highest values measured in tlie areas more frequented by the livestock, where the degradation of the vege- tation cover and the removal of tlie soil material are continuous. Finally, although the rate of soil loss in the dehesa is low, it is important froin a qua- litative point of view because it affects to the inost fertile horizon in the soil profile
Keywords: Dehesa; rainfall simulation; runoff; Season; sediment concentration; soil loss

Germination success, survival and seedling vigour of Quercus suber acorns in relation to insect damage - Branco, Manuela; Branco, Carmen; Merouani, Hachemi; Almeida, Maria Helena (Forest Ecology and Management, 2002)
This study assesses the effects of damage caused by Curculio elephas Gyll. (Coleoptera: Curculionidae) and Cydia splendana Hb. (Lepidoptera: Tortricidae) on mature acorns of cork oak trees, Quercus suber L., in Portugal. The average number of insect-attacked acorns varied between 68, 44 and 17%, in three sites, respectively. Acorns assorted into increasing damage classes had a decreasing acorn dry weight and a faster germination rate. The percentage of germination was very high (>90%) in all classes. Seedlings resulting from more intensely damaged acorns exhibited a slower growth rate and lower dry mass production than seedlings resulting from low damaged acorns.
Keywords: acorn germination; insect-attack; seedling production

A high resolution record of the last deglaciation in the southern Tyrrhenian Sea: environmental and climatic evolution - Buccheri, G.; Capretto, G.; Di Donato, V.; Esposito, P.; Ferruzza, G.; Pescatore, T.; Russo Ermolli, E.; Senatore, M. R.; Sprovieri, M.; Bertoldo, M.; Carella, D.; Madonia, G. (Marine Geology, 2002)
A multidisciplinary study was carried out on core C106 collected in the Salerno Gulf (southern Tyrrhenian Sea). Two tephra layers recovered in the core, δ18O record of Globigerinoides ruber and Globigerina bulloides and seven 14C calibrated ages provided the stratigraphic framework. The core sediments cover the last 28 kyr BP. Seismo-stratigraphic analysis of a high resolution acoustic profile, integrated by the dated core samples, allowed us to reconstruct the architecture and age of sedimentary bodies on the continental shelf. An integrated study based on different taxonomic groups (nannofossils, pteropods, foraminifera, and palynomorphs) provided palaeoclimatic trends, in agreement with changes in the isotopic composition of oxygen. The upper part of the Last Glacial period, the deglaciation phase and the Holocene were identified. Correlation between marine and continental records of palaeoenvironmental changes confirms a similar reconstruction of the last deglaciation as in the central and southern Mediterranean Sea. The Late Pleistocene–Holocene boundary was recognised at about 11.7 kyr BP. Between about 9.5 and 6 kyr BP and at 3.3 kyr BP some warmer episodes were recorded. The measured lower isotopic values, together with some features of the fossil assemblages recorded from 9.5 to 6 kyr BP, may be related to the oceanographic setting that led to the deposition of Sapropel S1 in the Mediterranean basin.
Keywords: isotopes; late quaternary; palaeoclimatology; sedimentology; seismic stratigraphy; Tyrrhenian Sea

How Plants Cope with Water Stress in the Field? Photosynthesis and Growth - Chaves, M. M.; Pereira, J. S.; MAROCO, J.; Rodrigues, M. L.; RICARDO, C. P. P.; OSÓRIO, M. L.; CARVALHO, I.; FARIA, T.; PINHEIRO, C. (Annals of Botany, 2002)
Plants are often subjected to periods of soil and atmospheric water deficit during their life cycle. The frequency of such phenomena is likely to increase in the future even outside today’s arid/semi‐arid regions. Plant responses to water scarcity are complex, involving deleterious and/or adaptive changes, and under field conditions these responses can be synergistically or antagonistically modified by the superimposition of other stresses. This complexity is illustrated using examples of woody and herbaceous species mostly from Mediterranean‐type ecosystems, with strategies ranging from drought‐avoidance, as in winter/spring annuals or in deep‐rooted perennials, to the stress resistance of sclerophylls. Differences among species that can be traced to different capacities for water acquisition, rather than to differences in metabolism at a given water status, are described. Changes in the root : shoot ratio or the temporary accumulation of reserves in the stem are accompanied by alterations in nitrogen and carbon metabolism, the fine regulation of which is still largely unknown. At the leaf level, the dissipation of excitation energy through processes other than photosynthetic C‐metabolism is an important defence mechanism under conditions of water stress and is accompanied by down‐regulation of photochemistry and, in the longer term, of carbon metabolism.
10.1093/aob/mcf10510.1093/aob/mcf105
Keywords: carbon assimilation; high temperature; Lupinus; photosynthesis; Quercus ilex; Quercus suber; stomatal functioning; Stress; Vitis vinifera; water-stress; xanthophyll cycle

A hydraulic model to predict drought-induced mortality in woody plants: an application to climate change in the Mediterranean - Martínez-Vilalta, J.; Piñol, J.; Beven, K. (Ecological Modelling, 2002)
The potential effects of climate change on vegetation are of increasing concern. In the Mediterranean region, the dominant impact of climate change is expected to be through the modiﬁcation of water balance. In this paper we present a model developed to predict drought-induced mortality of woody plants under different climatic scenarios. The model is physiologically-based and simulates water transport within individual woody plants, which can be isolated or competing for a common water resource. The model assumes that plant mortality is controlled by the carbon balance: when the plant is unable to transport water to the leaves it ceases to acquire carbon and, if this situation lasts long enough, it can no longer survive. In the particular application that we report in this study, two evergreen species are compared, Quercus ilex and Phillyrea latifolia, which were very differently affected by the acute drought that occurred in E Spain in summer 1994. While in some Q. ilex populations the amount of individuals that dried completely was up to 80%, P. latifolia showed almost no damage. During the years 1999 and 2000, canopy transpiration was monitored using sap-ﬂow sensors in individuals of these two species in a Holm-oak forest from NE Spain. A Generalised Likelihood Uncertainty Estimation (GLUE) approach was used to calibrate the model against sap-ﬂow measurements. The only difference between species that was introduced ‘a priori’ was that Q. ilex was more vulnerable to xylem embolism than P. latifolia (based on our own measurements in the study area). During the calibration process the information provided by the measured sap ﬂows was used to retain the more likely parameter sets for each species. These parameter sets were used in all the following simulations. The model was able to accurately simulate transpiration dynamics of the two species in the study area. When the meteorological conditions of summer 1994 were introduced, the model outputs also reproduced the differential impact that drought had on the two species studied. In the simulations under climate change two factors were explored: the increase in mean temperature (+1.5, +3 and +4.5 °C) through its effect on ET , and the duration of summer drought. Under any of the scenarios, mortalities were much higher for Q. ilex: while this species was predicted to survive with less than 5% mortality droughts of up to 84–94 days, the mortality of P. latifolia reached 5% between days 133 and 150. For droughts longer than 3 months, which is approximately the current drought duration in the study area for dry years, the mortality of Q. ilex increased sharply. These results are discussed in relation to the possible long-term impacts of climate change on Q. ilex-dominated forests
Keywords: climate change; drought-induced mortality; Mediterranean ecosystems; Modelling; phillyrea latifolia; Quercus ilex; water transport

Influence of climate on the seasonality of radial growth of cork oak during a cork production cycle - Costa, Augusta; Pereira, Helena; Oliveira, Ângelo (Ann. For. Sci., 2002)
The radial growth of mature cork oaks (Quercus suber L.) was studied during a 9-year production cycle using monthly dendrometer measurements and cork ring widths. The mean tree radial increase was 5.1 mm yr -1 and the cork increment accounting for 3.8 mm yr -1. The radial growth curves for cork, wood and stem were very similar, showing a decreasing trend along the production cycle. Cork increment was always the largest fraction of tree growth (on average 74%) and showed less inter-annual variations as compared to wood. Tree radial growth presented a clear within-the-year seasonal pattern, extending from March to October, with a maximum in June-July. The overall pattern of monthly growth distribution was similar among the years of the production cycle, but some inter-annual variations occurred with 1-2 month shifts or monthly growth rate decreases, related to climatic factors. Early spring growth was enhanced by winter rain, autumn growth by high summer rain and June increments by high temperatures during this month.
Keywords: climatic fluctuations; cork growth; Cork oak; dendroclimatology; diameter growth

The influence of cork oak pruning on the yield and growth of cork - Cañellas, Isabel; Montero, Gregorio (Ann. For. Sci., 2002)
Bearing in mind the importance of pruning as a silvicultural treatment in cork oak (Quercus suber L.) open woodland of the dehesa type, an experiment was designed to assess the effect of pruning on cork yield. This work was carried out in two ways: synchronically, comparing pruned sites with others which were either unpruned or pruned at different times, and diachronically, comparing pruned and unpruned trees within the same site. The five test sites (with forty trees in the synchronic and eighty in the diachronic plots) were selected in south-west Spain. In all cases measurements of the cork production were made in kilos per square metre of surface stripped, total cork yield per tree, and the mean thickness of stripped cork. Analysis was carried out using a paired data comparison test. The effect of pruning on yearly cork growth was also analysed by examining the annual growth rings. In the five plots analysed there were no significant differences (95% confidence intervals) between pruned and unpruned trees in terms of kilos of cork produced per square metre of surface stripped, nor for total cork yield per tree. Neither were there significant differences in annual cork growth rings, even when the pruning was carried out during the cork-stripping period.
Keywords: cork growth; Cork Production; pruned biomass; pruning; Quercus suber

Intercepção da Precipitação em Árvores Isoladas de Quercus rotundifolia Lam - David, Teresa Soares (Silva Lusitana, 2002)
Rainfall interception was monitored for two years in an isolated Quercus rotundifolia Lam. tree, in a low-density oak woodland (montado) near Évora. Interception loss was 21.7% of gross rainfall and 28% of tree evapotranspiration. Rainfall redistribution under the crown resulted in rainfall increases in upwind directions (South and West) and depletions downwind (North and East). Rainfall concentration in some areas beneath the crown is certainly of importance in explaining the spatial heterogeneity of the understory.
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: Evapotranspiration; interception loss; montado; rainfall redistribution

Land use changes, natural regeneration patterns, and restoration practices after a large wildfire in NE Spain: Challenges for fire ecology and landscape restoration - Espelta, J. M.; Rodrigo, A.; Habrouk, A.; Meghelli, N.; Ordonez, J. L.; Retana, J. (FIRE AND BIOLOGICAL PROCESSES, 2002)
Great wildfires have recently affected sub-Mediterranean areas of central Catalonia (NE Spain). The large extension of the burned areas, as well as the fact that non-fire-prone vegetation has been severely affected, lead to ponder over the natural regeneration patterns occurring, and over the best strategies to restore and manage the burned areas. In the present study, we review the land use changes and the natural regeneration patterns observed after the large wildfire that occurred in Bages-Bergueda in 1994. The fire resulted in: (i) the creation of new croplands and pastures in previously forested areas, (ii) the expansion of mixed oak (Quercus ilex and Q. cerrioides) coppices, (iii) the failure of natural regeneration of the dominant tree species (Pinus nigra), leading to the appearance of areas without any tree regeneration. In this context, we discuss the results of different experiments carried out to reforest P nigra stands and to ameliorate the structure of mixed oak coppices.
The following values have no corresponding Zotero field: periodical: FIRE AND BIOLOGICAL PROCESSES pub-location: PO BOX 321, 2300 AH LEIDEN, NETHERLANDS
Keywords: land use changes; Mediterranean areas; natural regeneration; Spain; wildfires

Linking photorespiration, monoterpenes and thermotolerance in Quercus - Penuelas, Josep; Llusia, Joan (New Phytologist, 2002)
* • The functions of two important plant processes, photorespiration and monoterpene production remain controversial. Here, we investigated one possible function, that of protection of plants from photodamage at high temperatures. * • Fluorescence, reflectance, monoterpene concentrations and visual leaf damage were measured in Quercus ilex seedlings exposed to temperature increases from 25 to 50°C (in 5°C steps) under photorespiratory (21% O 2 ) or nonphotorespiratory (2% O 2 ) atmospheres, and under control or terpene fumigation conditions. * • Lower variable to maximum fluorescence ratio (Fv : Fm: potential photochemical efficiency of photosystem II, PSII) and electron transport rate (ETR) were found in nonphotorespiratory conditions at temperatures greater than 35°C. Monoterpene concentrations were also lower, and leaf damage greater, in the low O 2 atmospheres. Monoterpene fumigation, which increased the foliar terpene concentrations by two- to four-fold, increased the photochemical efficiency between 35°C and 50°C, and decreased leaf damage, only under the nonphotorespiratory conditions. * • These results provide evidence that: photorespiration decreases photodamage, especially at high temperatures; photorespiration increases monoterpene production; plants are able to acquire exogenous monoterpenes and the acquisition response to temperature follows the stomatal conductance response; and monoterpenes can replace photorespiration in protection from photodamage at high temperatures, possibly by scavenging oxygen-reactive species, but they do not provide additional thermotolerance.
The following values have no corresponding Zotero field: publisher: Blackwell Science Ltd
Keywords: electron transport rate (ETR); fumigation; Fv : Fm; limonene; Monoterpenes; photochemical reflectance index (PRI); photorespiration; thermotolerance; α-pinene

Measurement and characterization of cellulase activity in sclerophyllous forest litter. - Criquet, Stéven (Journal of microbiological methods, 2002)
Cellulases are enzymatic proteins which hydrolyze cellulose polymers to smaller oligosaccharides, cellobiose and glucose. They consist in three major types of enzymes: endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) and beta-glucosidases (EC 3.2.1.21) which play an essential role in carbon turnover of forest ecosystem. The aim of this study was firstly to determine the parameters (i.e. buffer type, pH, temperature, quantity of litter, incubation time and reagent type) which affect the measurement of cellulase activity in a sclerophyllous forest litter, and secondly to compare two methods for measuring cellulase activity: a direct method and an extraction method. In the direct method, the litter was directly incubated with a buffered solution containing the enzyme substrate, whereas in the extraction method, the cellulases were firstly extracted before measuring their activity. The results were compared with other studies about soil cellulase activity, and it appeared that several parameters (buffer type, pH, temperature and sample quantity) which influence the measurement of cellulase activity differ according to whether a soil or a litter is considered. Concerning the procedure used for the measurement of cellulase activity, results showed that the activity values were higher when using an extraction procedure than when using a direct procedure. The extraction procedure, combined with a concentration stage of the extract, also allowed electrophoretic analysis (PAGE) of the cellulases extracted from the litter. The electrophoretic pattern revealed two cellulase isoenzymes which may be related to the occurrence of two pH-activity peaks of these enzymes when citrate buffer was used for the measurement of cellulase activity in the litter.
The following values have no corresponding Zotero field: accession-num: 11997167
Keywords: Buffers; Cellulase; Cellulase: analysis; Cellulase: isolation & purification; Cellulose; Cellulose: metabolism; Endoglucanase; Extraction; Hydrogen-Ion Concentration; Isoenzyme; Isoenzymes; Isoenzymes: analysis; litter; Plant Leaves; Plant Leaves: enzymology; Quercus; Quercus: enzymology; Temperature; Trees

Modelling start of oak pollen season in different climatic zones in Spain - García-Mozo, H.; Galan, C.; Aira, M. J. (Agricultural and Forest Meteorology, 2002)
Quercus pollen and meteorological data for several years from eight sites in Spain have been statistically analysed to select the threshold temperature and calculate the mean heat accumulation for predicting the Quercus pollination start in different climatic areas. The growing degree days method, which assumes the daily temperature varies as a sine wave, was used for heat accumulation calculations. Threshold temperatures between 4 and 12 ◦ C were chosen using linear regression equations forced through the origin and their root mean square error (RMSE) of predicted against the observed dates for each observation site. Above the threshold, the average growing degree days (up to 1999) for the studied years was taken as the predictor value. Results showed a relationship between the selected threshold and elevation and a stronger and statistically signiﬁcant correlation between threshold and yearly mean temperature, for each site. Regression analysis indicated that the selected threshold and the calculated heat accumulation were optimum for most of the localities. The validity of the results was tested using the meteorological data for the year 2000 as independent variable and this conﬁrmed that there were only a few days difference between the predicted and observed day of the ﬁrst pollen release for most of the studied localities
Keywords: Aerobiology; oak forest; Phenology; pollen; threshold temperature

Morphological segmentation of remotely sensed forest covers in high spatial resolution images - Barata, T.; Pina, P. (MATHEMATICAL MORPHOLOGY, PROCEEDINGS, 2002)
In this paper novel algorithms developed to automatically segment forest cover types are presented. The digital image analysis followed is mainly based on mathematical morphology operators and exploits the textural features in high spatial resolution images. These input images consist of true colour digital orthophotos and the studied forest covers consist of the main occurrences in Portugal: olive trees, cork oak trees, pine and eucalyptus trees.
The following values have no corresponding Zotero field: periodical: MATHEMATICAL MORPHOLOGY, PROCEEDINGS pub-location: PO BOX 89 (EAST ALBERT ST), EAST MELBOURNE, 3002, AUSTRALIA
Keywords: forest covers; high spatial resolution images; segmentation; textural features

Nitrogen circulation in a Mediterranean holm oak forest, La Castanya, Montseny, northeastern Spain - Avila, Anna; Rodrigo, Anselm; Rodà, Ferran (Hydrology and Earth System …, 2002)
Bulk deposition, wet-only deposition, throughfall and dry deposition inferred from washing foliage and surrogate surfaces were used to describe inorganic N inputs to a forested catchment in the Montseny Mountains (La Castanya, Catalonia, Spain). Bulk inputs of inorganic N were moderate, with a mean of 5.7 kg N ha -1 yr -1 , ranging between 4 and 10 kg N ha -1 yr -1 for the period 1983 to 2000. Dry deposition fluxes estimated from washing branches added about 9 kg N ha -1 yr -1 to wet inputs and the total atmospheric deposition was estimated in 15 kg N ha -1 yr -1 . Despite this substantial input flux, nearly all the inorganic nitrogen was retained within the forest ecosystem: NH4 + and NO3 - concentrations decreased dramatically as water crossed the canopy and the soil profile. In the stream, at baseflow conditions, NH4 + and NO3 - concentrations were always below the analytical detection limit (< 2 µeq L -1 ). Only briefly during peak flows did NO3 - concentrations increase up to 100 µeq L -1 . Averaged over 10 years (1984-1994), the export of N at the catchment outlet was 0.05 kg N ha -1 yr -1 . This indicates a very tight N cycling allowing for an increase of N availability in these undisturbed forest ecosystems.
Keywords: ammonium; bulk deposition; Dry deposition; la castanya; montseny; nitrate; soil water; Spain; throughfall

Nitrogen deposition in Mediterranean forests. - Roda, F.; Avila, a; Rodrigo, A. (Environmental pollution (Barking, Essex : 1987), 2002)
Atmospheric deposition of inorganic nitrogen was studied at two forested sites in the Montseny mountains (northeast Spain), peripheral to the Barcelona conurbation, and at a nearby lowland town, using bulk deposition, wet-only deposition, throughfall, and dry deposition inferred from branch-washes and surrogate surfaces (metacrylate plates). Bulk deposition inputs of ammonium and nitrate did not show significant temporal trends over a 16-year period. Bulk inputs of inorganic N were moderate, ranging from 6 to 10 kg N ha(-1) year(-1) depending on the time period considered and the degree of site exposure to polluted air masses from the Barcelona conurbation. Large dry-sedimented particles played a minor role, since wet-only inputs were virtually identical to bulk inputs. On the contrary, branch- and plate-washes indicated substantial dry inputs of N gases and small particles. Total atmospheric deposition was estimated at 15-22 kg N ha(-1) year(-1), most of it being retained within the studied broadleaved evergreen forests. Ecosystem N availability is thus likely to be increasing in these forests.
The following values have no corresponding Zotero field: accession-num: 11939283
Keywords: Air Pollutants; Air Pollutants: analysis; Biological Availability; Ecosystem; Environmental Monitoring; Gases; Geologic Sediments; Geologic Sediments: chemistry; Mediterranean Region; nitrogen; Nitrogen: analysis; Particle Size; Trees; Trees (citation)

Niveles de cargas ganaderas en la dehesa extremeña - Escribano, M.; Rodríguez de Ledesma, A.; Mesías, F. J.; Pulido, F. (Archivos de zootecnia, 2002)
This work analyzes the data collected from 143 sheep and/or cattle farms, representatives of the Extremaduran dehesa (semiarid grazing areas of the SW of Spain). A random survey was carried out in 2000, with an error of less than 5 percent and a confidence level of 95 percent. The aim of the survey was the evaluation of the stocking rate levels of these farms in 1999 and their evolution from 1993, first year after the CAP Reform of 1992. The effects of farm size for different stocking rates are studied. Significant differences were observed (p<0,05 and p<0,01) between the bigger and the lesser farm sizes. This shows a higher productive intensification when the grazing surface decreases. It is to mention a high correlation between the cattle units in sheep farms (UGMo) and the cattle units in the whole sample (UGMt) (r=0,867; p<0,01), as well as the association between sheep density and pig density variables (r=0,773; p<0,01). On the other hand, we can observe an inverse correlation between the levels of livestock density and the farm size, which is more significant in cattle farms.
Keywords: dehesas; Grazing; Stocking rate; Structural analysis

The organosolv fractionation of cork components - Cordeiro, N.; Neto, C. P.; Rocha, J.; Belgacem, M. N.; Gandini, A. (HOLZFORSCHUNG, 2002)
Extractive-free cork from Quercus suber L. was submitted to organosolv fractionation and the effects of different process variables, such as ethanol/water ratio, temperature, time and the presence of acidic or alkaline catalysts, were studied. The variation of the relative proportions of extracted components, as a function of the processing conditions, could thus be established. Whereas the addition of 0.1 M acetic acid only increased the yield of extracted materials from about 15 to 23 %, the use of sodium hydroxide, at the same concentration, produced a jump to 76 %. In the case of the alkaline organosolv fractionation. an increase in process temperature, time and catalyst concentration led to an increase in the extraction yield, although in some cases this increase did not follow a sustained trend, as in the case of reaction time. Increasing the ethanol/water ratio led to a higher selectivity in favour of suberin extraction. Residual cork from different organosolv processes was characterised by FTIR and C-13 solid-state NMR. The latter technique provided some valuable information about both process selectivity and cork morphology, particularly with respect to the positioning of suberin macromolecules in the cell wall.
The following values have no corresponding Zotero field: pub-location: GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY publisher: WALTER DE GRUYTER & CO
Keywords: C-13 NMR; Cork; ethanol/water extraction; FTIR; organosolv fractionation; Quercus Suber L; suberin

Patch occupancy by stone martens Martes foina in fragmented landscapes of central Spain: the role of fragment size, isolation and habitat structure - Virgós, Emilio; García, Francisco J. (Acta Oecologica, 2002)
We studied the response to forest fragmentation of a generalist carnivore, the stone marten Martes foina, in highly fragmented landscapes of central Spain. Five different areas (n = 178 fragments) in central Spain were surveyed. This paper analyses the relationship between fragment use by martens (measured through scat presence) and a series of variables related to the size, isolation and vegetation structure of each fragment by means of stepwise logistic regression. Size and isolation have an important effect on stone marten presence in fragments. Our results were similar to those found for other marten species in landscapes with coarse-grain fragmentation, but they contrast with other studies conducted in landscapes with ﬁne-grain fragmentation. These data suggested that in highly fragmented landscapes, size and isolation factors resulting from forest fragmentation were responsible for determining marten responses, irrespective of their habitat generalism. Management policies for the stone marten in highly fragmented scenarios require the maintenance of large forests near continuous forest tracts in mountains or riparian woodlands
Keywords: agricultural landscapes; Forest fragmentation; iberian peninsula; martes foina; size-isolation effects

Patterns and processes of Late Quaternary environmental change in a montane region of southwestern Europe - Carrión, J. S. (Quaternary Science Reviews, 2002)
This paper examines the Late Quaternary (c. 20,300–o505 cal yr BP) environmental history of Siles, a lake situated at 1320 m in the Segura mountains of southern Spain, with the goalof establishing the mechanisms exerting controlon vegetation change. Palaeoecological indicators include pollen, microcharcoal, spores of terrestrial plants, fungi, and non-siliceous algae, and other microfossils. The Siles sequence is shown to be sensitive to climatic change, although the control exerted by climate on vegetation is ultimately shaped by disturbances and species interactions, determining the occurrence of century-scale lags and threshold responses. Biotically induced changes of vegetation are also shown at the intrazonal level of variation. The new sequence is placed in the context of two previous records to postulate a picture of Holocene environmental change for the Segura region. The existence of mid-elevation glacial refugia for a number of temperate and Mediterranean trees is shown. A mid-Holocene phase (c. 7500– 5200 cal yr BP) emerges regionally as the time of maximum forest development and highest lake levels. The early Holocene occurs as a generally dry, pyrophytic period of pine forests, with grassland scrub in high altitudes, and the late Holocene as a period of protracted vegetation sensitivity, with return to development of pine forests, spread of xerophytic communities, and increased ﬁre activity, under the context of dry spells, localized anthropogenic disturbance, and shallowing and desiccation of lakes. Several events described here correlate with established times of abrupt transitions in the climates of northern Europe, the Mediterranean basin, north Africa, and the Sahel
Keywords: Holocene; Mediterranean (voyant); Pollen analysis; vegetation belts

Phytoclimatic characterization of holm-oak provenances (Quercus ilex L.) in the Central-Northern Iberian Peninsula - Garcia Lopez, J. M.; Gonzalo Jimenez, J.; ALLUÉ CAMACHO, C. (Forest Systems, 2002)
This paper presents some contributions to the phytoclimatic characterization of stands of holm-oak (Quercus ilex. L.) in the centre-north of the Iberian Peninsula and the testing of a method of phytoclimatic homologation applicable to the characterization of provenances of the species. For the phytoclimatic characterization, 432 sampling points in the Province of Burgos were considered, corresponding to the centres of cartographic tessellae of actual vegetation in which holm-oak was the principle species of the forest (18,965 ha). The phytoclimatic diagnosis followed the phytoclimatic models of Allué-Andrade. Phytoclimatic territorial models were constructed in digital format on the basis of preliminary territorial factorial estimations, which were used to determine phytoclimatic terns. Based on the establishment of phytoclimatic ambits for the existence of holm-oak stands in Burgos and stratification in accordance with the five phytoclimatic subtypes (VI(IV)1, VI(IV)2, VI(VII), VI(V) and VI), phytoclimatic homologation was performed in three phases of increasing strictness, all based on a comparison of phytoclimatic terns derived from the general and specific phytoclimatic systems. In the strictest homologation, an adequate and territorially compact degree of discrimination was achieved for 2.622.500 ha (Quercus ilex subsp. ballota) and 116.00 ha (Quercus ilex subsp. ilex) in the centre-north of the Iberian Peninsula. The marked edaphic azonality of the species was an important factor in the interpretation of the results.
Keywords: holm-oak; homologation; phytoclimatology; provenances; Quercus ilex L. subsp. ballota (Desf.) Samp.; Quercus ilex L. subsp. ilex

Propagação Vegetativa de Sobreiros Seleccionados - de Freitas, Maria Isabel Carrasquinho (Silva Lusitana, 2002)
The aim of this investigation was to evaluate the possibilities of vegetative propagation techniques of adult cork oak trees so as to develop an approach applicable to a genetic improvement breeding program. Bud grafting and cuttings were used to multiply and mass propagate selected cork oak trees. Forty-six cork oak trees were reproduced from clone banks. September proved to be a better season for grafting than June/July. Rooting season and the temperature of the rooting substrate were demonstrated to be important factors in juvenile cuttings response. The highest rooting ability was achieved in August with a rooting substrate temperature of 28°C (57.0%). The best rooting rate was obtained by maintaining cuttings in rooting media for four months. The application of IBA influenced rooting ability both in cuttings from seedlings and those from the clone bank. Nevertheless, juvenile material needed a lower IBA concentration (0.5%) than the older material (1%). The clone and age of grafting were shown to influence the rooting ability. The decrease of rooting ability with age of grafting requires a dynamic management of the clone bank. The vegetative propagation of selected adult cork oak trees seems to be a viable technique, establishing a prior clone bank, by means of grafting, and then mass propagation through cuttings of this material.
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: Bud grafting; Clones; Cuttings; Quercus suber L.; vegetative propagation

Purification of a new isoform of laccase from a Marasmius quercophilus strain isolated from a cork oak litter (Quercus suber L.) - Farnet, A. M.; Criquet, S.; Pocachard, E.; Gil, G.; Ferré, E. (MYCOLOGIA, 2002)
A new isoform of laccase from Marasmius quercophilus is described in this study. The strain of this white-rot fungus was isolated for the first time on a cork oak litter. This isoform exhibited certain common properties of laccases (a molecular weight of 65 Kda, an optimum pH of 6.2 with syringaldazine). But this laccase has also particularly novel features: the best activity measured was observed at high temperatures (80 C) and this isoform was not inhibited with EDTA. Furthermore, this induced laccase was able to transform most of the aromatic compounds tested without the addition of mediators to the reaction mixture, and the transformation of certain chlorophenols (2-chlorophenol and 2,4-dichlorophenol) by a laccase isoform from M. quercophilus is reported here for the first time. We also demonstrate the importance of 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) as a mediator since it allowed veratryl alcohol and p-hydroxybenzoic acid transformation. Moreover, new products of transformation were observed using the combination of ABTS with this isoform of laccase.
The following values have no corresponding Zotero field: pub-location: PUBLICATIONS DEPT, BRONX, NY 10458 USA publisher: NEW YORK BOTANICAL GARDEN
Keywords: aromatic compounds; mediator; polyphenoloxidase; white-rot fungus

Radiocarbon as a biomarker of urban pollution in leaves of evergreen species sampled in Rome and in rural areas (Lazio—Central Italy) - Alessio, M.; Anselmi, S.; Conforto, L.; Improta, S.; Manes, F.; Manfra, L. (Atmospheric Environment, 2002)
The aim of the present study is the use of 14 C, sampled in leaves of evergreen species, as a natural geochemical marker to estimate the contribution of artiﬁcial sources (heating plants, vehicles, etc.) to the complex of atmospheric gases in an urban environment. Leaves were chosen due to sampling easiness and their reliability: in particular the evergreen species, being exposed all the year round to pollutants are especially indicated for bioindication and biomonitoring studies. The response to atmospheric pollutants has been studied of two plant species (Quercus ilex L., Pinus pinea L.) measuring isotopic ( 14 r, d 13 C), chemical (Pb concentration) and ecophysiological (gaseous exchange and leaf ﬂuorescence of chlorophyll a) parameters. Leaves of holm-oaks and stone pine needles collected over a 3-year time span in an urban park in Rome (Villa Ada) and in reference localities outside the city on the Tyrrhenian coast and in the preAppennine area have been analysed. In Villa Ada measurements were carried out along a transect from the road bordering the park towards the interior; all the parameters, together in agreement, showed a decreasing pollution gradient towards the inner park. It was possible to estimate a 5.570.3% contribution of CO2 from fossil fuels close to the road, decreasing to 1.770.3% at o300 m from it towards the inner park. The isotopic analyses conducted on stone pines and holm-oaks show that 14 C provides indications on the degree of pollution from fossil fuels, while d 13 C appears to be conditioned mainly by the interspeciﬁc difference, and also by many other environmental factors that affect the plant functionality. Results conﬁrmed that radiocarbon is a useful tool in environmental studies, allowing to quantify the contributions of CO2 of anthropic origin: this parameter, together with appropriate isotopic, chemicaland ecophysiological analyses, could provide a good indication of the ‘‘air quality’’ in urban and rural contexts.
Keywords: air quality; carbon isotopes; co 2; lead; photosynthesis

Seasonal and species-specific response of VOC emissions by Mediterranean woody plant to elevated ozone concentrations - Llusia, J.; Penuelas, J.; Gimeno, B. S. (ATMOSPHERIC ENVIRONMENT, 2002)
Although certain factors controlling plant emission rates of volatile organic compounds (VOCs) are reasonably well understood, the influence of elevated ozone concentrations as abiotic stress is mostly unknown. Therefore, we studied the effects of ozone concentrations on seasonal biogenic volatile organic compound (BVOC) emissions by different Mediterranean plant species in open top chambers (OTC). Three ozone treatments were established: filtered air (F), non-filtered air (NF), and fumigated air (NF +) adding 40 nl l(-1) of ozone over NF. We studied the response of VOC emission in saplings of four Mediterranean woody plant species and subspecies: Ceratonia siliqua L., Olea europaea L., Quercus ilex spp. ilex L., and Quercus ilex spp. rotundifolia L. as representative of natural Mediterranean vegetation. No visible symptoms were detected on the leaves. No significant effect was found on net photosynthetic rates or stomatal conductance except for an increase in net photosynthetic rates in Quercus ilex ilex in spring and summer and an overall slight increase in Quercus ilex rotundifolia. Emissions of the total VOCs from Ceratonia siliqua in summer, and from Olea europaea and Quercus ilex rotundifolia in spring increased in ozone fumigated OTC in comparison with F or NF OTC. Decreased emissions were found in Quercus ilex rotundifolia in summer. There were no significant differences between ozone fumigation treatments for the other plant species and seasons. When considering particular VOCs, the results were also variable among species and time of the year. While alpha-pinene emissions decreased with ozone fumigation in Olea europaea, alpha-pinene and limonene emissions increased in Quercus ilex ilex. The responses of these particular VOCs did not always match the responses of total VOCs. In spite of this strong variability, when considering overall annual data for all species and seasons, there were increased net photosynthetic rates (37%) and limonene (95%) and total VOC (45%) emission rates in ozone-fumigated plants, whereas stomatal conductance did not change. Since VOCs are precursors of ozone, the increase in BVOC emission as a consequence of elevated tropospheric ozone concentrations may lead to positive feedback mechanisms in ozone formation. (C) 2002 Elsevier Science Ltd. All rights reserved.
The following values have no corresponding Zotero field: pub-location: THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND publisher: PERGAMON-ELSEVIER SCIENCE LTD
Keywords: biogenic VOCS; Ceratonia siliqua; Olea europaea; Quercus ilex ilex; Quercus ilex rotundifolia; terpenes; tropospheric ozone

Seasonal pattern of monoterpene synthase activities in leaves of the evergreen tree Quercus ilex - Fischbach, Robert Josef; Staudt, Michael; Zimmer, Ina; Rambal, Serge; Schnitzler, Jörg-Peter (Physiologia Plantarum, 2002)
Monoterpene synthase activities were measured in current year and 1-year-old leaves of holm oak (Quercus ilex L.). The monoterpene synthase activities of the leaves strongly changed with leaf development and leaf age. Enzyme activities increased rapidly in spring after leaf emergence, reaching maximum values in summer, which declined during the following winter period. In the next spring monoterpene synthase activities recovered in the old leaves to about one-third of values in the previous years and showed a similar seasonal variation as in young leaves. In both leaf age classes the pattern of enzymatic monoterpene formation was stable with α-pinene (33%), β-pinene (28%), and myrcene (26%) as prominent compounds followed by minor fractions of sabinene (10%) and limonene (3%). Monoterpene emission correlated with the activity of the synthetizing enzymes, indicating that monoterpene synthase activities in Q. ilex reflect the seasonal monoterpene emission potential of the leaves.
The following values have no corresponding Zotero field: publisher: Munksgaard International Publishers accession-num: 12060257
Keywords: monoterpene emissions; monoterpene synthase activities; Quercus ilex; seasonal patterns (voyant)

Shoot growth efficiency and production of Quercus ilex L. in different climates - Crescente, M. F.; Gratani, Loretta; Larcher, Walter (Flora-Morphology, Distribution, …, 2002)
Structural and functional traits of Quercus ilex L. were monitored in plants growing in the climax area (Castelporziano, Rome; site A) and at the northern distribution limit (Nago, Trento; site B) in Italy. The most distinctive climatic differences between the two sites were duration and frequency of drought, heat spells in summer at site A, and the occurrence of frost and sub-zero temperatures in winter at site B. The potential productivity of Quercus ilex lies in its tendency to be slow growing with maximum vegetative activity from the end of April to the end of June at Castelporziano, and from the middle of May to the middle of July at Nago, when air temperatures favoured the highest photosynthetic rates (90–100%). The lower shoot biomass production at site B was due to the lower relative growth rates in shoot length (RGRl < 20%) and in shoot dry mass (RGRm <11%). The lower shoot length growth efficiency (LE < 62%) at the northern limit was related to the low temperatures in winter and beginning of spring which reduced favourable periods (<20% than site A) for photosynthetic carbon gain and growth dynamics. It resulted in a lower total leaf surface area per shoot (<60% than site A) and a reduced shoot leaf mass (<31%).
Keywords: Net photosynthesis; Phenology; Quercus ilex L; Relative growth rate; shoot length growth efficiency; shoot production

Simulação e projecção de alternativas de gestão para o montado de sobro - Falcão, André (2002)
A simulação de alternativas de gestão para o montado de sobro reveste-se de diversas subtilezas que a diferenciam dos tradicionais sistemas silvícolas de produção. Isto devido em particular à ecologia da espécie e à forma tradicional como estes sistemas têm sido geridos. De particular relevo é o facto da principal intervenção produtiva no montado (o descortiçamento) não ter um efeito destrutivo nem obrigar a uma regeneração do coberto arbóreo. Outra questão não menos premente é a dificuldade em elaborar modelos de produção e de crescimento desta espécie que se adequem à integração num simulador de alternativas de gestão. Finalmente, e tendo os modelos de produção adequados, a questão é fundamental é: como se gere o montado de sobro? quais são as possibilidades que um produtor tem de gerir o seu montado? Este documento procura responder a estas questões. Assim, descreve-se o módulo de apoio à decisão do programa SADGEM. Este componente é constituido por 3 aplicativos distintos: Um simulador de alternativas de gestão, um gerador de restrições e um modelo de gestão previamente parametrizado. O gerador de alternativas de gestão usa informação de inventário e geográfica recuperada directamente do SGBD. Neste trabalho detalha-se, em primeiro lugar, o modelo de produção utilizado para efectuar a simulação. Seguidamente, descrevem-se os requisitos de dados necessários para alimentar o modelo e finalmente todos os mecanismos de geração de alternativas de gestão para montados de sobro. Dá-se ainda algum relevo ao tipo de informação produzida pelo simulador e sistema de pré-processamento de soluções.
The following values have no corresponding Zotero field: secondary-title: Documento Técnico periodical: Documento Técnico
Keywords: alternativas; cortiça; Descortiçamento (voyant); gestão; idade; montado; simulação

Soil evolution over the Quaternary period in a Mediterranean climate (SE Spain) - Ortiz, I.; Simón, M.; Dorronsoro, C.; MartÄ±n, F.; GarcÄ±a, I. (Catena, 2002)
Palaeosols in the Granada Basin (SE Spain) have been studied in two different situations: surface soils on geomorphically stable surfaces since the Early Pleistocene with younger pedogenic overprinting and buried soils on unstable surfaces from the Middle –Late Pleistocene on which successive erosional – depositional episodes have alternated with pedogenic episodes. For each soil clay and iron accumulation indices, the Fet + Al t /Si t ratio, clay mineralogy and micromorphological features were used to estimate the degree of soil development. From the Early to the early Late Pleistocene, the main pedogenic processes were the leaching of carbonates, weathering, illuviation and rubification, which resulted in Bt horizons with red colours, clay texture, clay coatings and kaolinite neoformation. The degree of weathering and the development of these Bt horizons varied over time, and the soils that formed on the surfaces from the Early Pleistocene show strongest weathering and development. However, after their formation, there were periods in which they were partially truncated and recalcified, resulting in polygenetic soils. The different degrees of development of the buried soils during the last 474,000 years indicate that the wettest warm period was stage 7 and the driest, stage 5. Stages 9 and 11 must have had climates with intermediate wetness. Since the clay accumulation and iron oxide accumulation indices, the differences in Fet + Al t /Si t ratio between Bt and C horizons, the extent of kaolinite neoformation and the micromorphological features of the soils formed during stage 7 are all similar to the surface soils that formed on Early Pleistocene deposits, these features cannot be used to date surfaces older than 242,000 BP. By contrast, the soils that formed during stage 7 and later periods show different extents of development and thus can be used for the approximate dating of landforms.
Keywords: Buried soils; climatic changes; Pleistocene; Relict soils; Soil development

A spatial statistical analysis of cork oak competition in two Portuguese silvopastoral systems - Paulo, M. J.; Stein, A.; Tomé, M. (Canadian Journal of Forest Research, 2002)
This paper considers competition among cork oaks (Quercus suber L.) at three plots in two representative Portuguese stands. It uses spatial point pattern functions to describe densities and quantify differences among stands. Relations between cork oak characteristics and indices measuring intertree competition are modelled. Tree competition has a significant effect on tree crown characteristics. In particular, cork oaks with much competition have smaller and more elongated crowns. A standard model that relates crown diameter with diameter at breast height was improved. The R2 value increased from 0.53 to 0.63 by including a crown shape parameter and competition indices.
doi: 10.1139/x02-107doi: 10.1139/x02-107The following values have no corresponding Zotero field: publisher: NRC Research Press
Keywords: Competition (voyant); Cork oak; crown characteristics

Stocking rate and capital indicators in extensive sheep farms (sw spain) - Escribano Sánchez, Miguel; Rodríguez de Ledesma Vega, Antonio; Mesías Díaz, Francisco Javier; Pulido García, Francisco (Arch. Zootec, 2002)
The animal production systems in the SW of the Iberian Peninsula are characterized by extensive livestock farming. The data for the present study were collected by survey in the year 2000 from 96 dehesa sheep farms in Extremadura. We studied the stocking rate effects on a number of capital indicators for each farm. The data were analysed for three stocking rate levels: low (<0.25 UGM/ha), medium (0.25-0.5 UGM/ha), and high (0.5 UGM/ha). The differences were compared by analysis of variance, following the GLM procedure.
Keywords: Economic analysis; Extensive system; Sheep; Stocking rates

Structural and functional traits of Quercus ilex in response to water availability - Bussotti, Filippo; Bettini, Davide; Grossoni, Paolo; Mansuino, Silvia; Nibbi, Renzo; Soda, Costanza; Tani, Corrado (Environmental and Experimental Botany, 2002)
Water potential and morpho-anatomical parameters were measured, during the course of 1 year, on leaves of Quercus ilex trees growing in two coastal stands in Tuscany (Central Italy) with different conditions of water availability: Colognole (CL, mesic site) and Cala Violina (CV, xeric site). Morpho-anatomical measurements included: general leaf features and sclerophylly indices (surface area, thickness, mass per area and density), leaf moisture indices (water content, relative water content, succulence) and histochemical analysis (detection and localization of cutine and tannins in the leaves and starch reserves in the twigs). During the warmest and driest period (August) pre-dawn water potential (pd ) in Holm-oak leaves reached −2.7 MPa at CV and −0.6 MPa at CL. Leaf surface was lower (−34%) and total leaf thickness (+10%), as well as spongy-palisade parenchyma ratio (+20%) were higher at CV. The sclerophylly parameters (leaf mass per area and leaf tissue density) were higher at CV than at CL (+24% leaf mass per area and +19% leaf tissue density). Among the moisture parameters, water content was higher at CL (+8%) and succulence was higher at CV (+13%). No differences in relative water content were observed between the two sites. All the parameters considered were substantially stable during the study period, with the exception of relative water content at CL, that ﬂuctuated within the year. Histochemical analysis revealed a greater thickness of the upper cuticular layer at CV, whereas there were no differences in tannin distribution and content between the two sites. Differences in starch storage were detected in branchlets: it was abundant in CV but very scarce at CL. The strategies of Quercus ilex to cope with water stress were discussed at morpho-structural level.
Keywords: leaf structure; starch; Tannins; water potential

Transpiração em Árvores Isoladas de um Montado de Azinho: Evolução Sazonal e Condicionantes Hidráulicas - David, Teresa Soares; Ferreira, Isabel; Pereira, João Santos; Cohen, Shabtai; David, Jorge Soares (Silva Lusitana, 2002)
Sapflow and related variables were monitored for two years in an isolated Quercus rotundifolia Lam. tree, in a low density oak woodland (montado) near Évora. The study aimed at identifying tree strategies in adverse soil and climatic conditions in order to understand the conditions for survival and sustainability. Seasonal variations in transpiration, mainly related to solar radiation and vapour pressure deficit, showed a peak in summer (3 mm day-1) even in dry soil conditions. Water availability to the roots did not change much over time, due to the likely access of the root system to an aquifer located at 13 m depth. Stomatal control prevents transpiration from exceeding the maximum water uptake capacity by the roots. An upper limit is thus imposed on transpiration, preventing leaf water potential to decrease below -3,2 MPa, which may probably be the threshold for cavitation
The following values have no corresponding Zotero field: publisher: scielopt
Keywords: aquifer; Evapotranspiration; Quercus rotundifolia Lam.; sapflow

Trichomes and photosynthetic pigment composition changes: responses of Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L. to Mediterranean stress conditions - Morales, F.; Abadia, A.; Abadía, J.; Montserrat, G.; GIL-PELEGRÍN, E. (Trees, 2002)
Sun and shade leaves of two Mediterranean Quercus species, Quercus ilex subsp. ballota (Desf.) Samp. and Quercus coccifera L., were compared by measuring leaf optical properties, photosynthetic pigment composition and photosystem II efficiency. The presence of trichomes in the adaxial (upper) leaf surface of Q. ilex subsp. ballota seems to constitute an important morphological mechanism that allows this species to maintain a good photosystem II efficiency during the summer. Q. coccifera has almost no trichomes and seems instead to develop other physiological responses, including a smaller light-harvesting antenna size, higher concentrations of violaxanthin cycle pigments and a higher (zeaxanthin + antheraxanthin)/(violaxanthin + antheraxanthin + zeaxanthin) ratio. Q. coccifera was not able to maintain a good photosystem II efficiency up to the end of the summer. In Q. ilex subsp. ballota leaves, natural loss or mechanical removal of adaxial-face leaf trichomes induced short-term decreases in photosystem II efficiency. These changes were accompanied by deepoxidation of violaxanthin cycle pigments, suggesting that the absence of trichomes would trigger physiological responses in this species. Our data have revealed different patterns of response of Q. ilex subsp. ballota and Q. coccifera facing the stress conditions prevailing in the Mediterranean area.
Keywords: adaxial epidermis; photoprotection; Quercus; Trichomes

Typologie et dynamique des chênaies vertes en Algérie - Dahmani-Megrerouche, M. (Forêt Mediterranéenne, 2002)
Cet article traite des différents groupements végétaux relevant de la dynamique des chênaies vertes en Algérie, et de leurs différents stades de dégradation. Lorsque l’on connait la valeur écologique du chêne vert, en particulier, dans un pays comme l’Algérie, son rôle contre la désertification et la disparition des sols, les résultats de cette analyse ne peuvent qu’aider les gestionnaires à mieux appréhender la situation
Keywords: chêne vert; matorral; phytosociologie; relation sol-végétation; structure (voyant)

The viscoelastic properties of cork - Mano, J. F. (Journal of materials science, 2002)
The viscoelastic properties of cork (from Quercus suber) have been investigated in the temperature range −40 to 120 ◦ C using the technique of Dynamic Mechanical Analysis (DMA). The results were compared with dielectric data previously reported. A relaxation was detected with a maximum in tan δ at ca 20 ◦ C (f = 1 Hz) and with a mean activation energy of 140 kJ ·mol−1 . A decrease in the intensity of the relaxation and an increase of the storage modulus is observed when cork is previously subjected to an annealing process above 60 ◦ C. This result is in agreement with previously reported dielectric data. Thermogravimetric experiments seem to conﬁrm that such effect could be caused by the desorption of water molecules. Specimens oriented along the prismatic direction presented higher storage modulus than the ones oriented along the transverse prismatic direction. The rheological properties of cork also showed a dependence upon the mechanical mode used during measurements: for example, the stiffness is the highest for the tensile mode and the lowest for the compression mode.
Keywords: Cork; Dynamic mechanical analysis (DMA); Relaxation; viscoelastic properties (voyant)