<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sardans, J.</style></author><author><style face="normal" font="default" size="100%">Gargallo-Garriga, A.</style></author><author><style face="normal" font="default" size="100%">Pérez-Trujillo, M.</style></author><author><style face="normal" font="default" size="100%">Parella, T. J.</style></author><author><style face="normal" font="default" size="100%">Seco, R.</style></author><author><style face="normal" font="default" size="100%">Filella, I.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Metabolic responses of Quercus ilex seedlings to wounding analysed with nuclear magnetic resonance profiling</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Asparagine</style></keyword><keyword><style  face="normal" font="default" size="100%">choline</style></keyword><keyword><style  face="normal" font="default" size="100%">glucose</style></keyword><keyword><style  face="normal" font="default" size="100%">herbivory</style></keyword><keyword><style  face="normal" font="default" size="100%">NMR metabolomics</style></keyword><keyword><style  face="normal" font="default" size="100%">quercitol</style></keyword><keyword><style  face="normal" font="default" size="100%">quinic acid</style></keyword><keyword><style  face="normal" font="default" size="100%">wounding</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2013///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/plb.12032</style></url></web-urls></urls><pages><style face="normal" font="default" size="100%">n/a - n/a</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Plants defend themselves against herbivory at several levels. One of these is the synthesis of inducible chemical defences. Using NMR metabolomic techniques, we studied the metabolic changes of plant leaves after a wounding treatment simulating herbivore attack in the Mediterranean sclerophyllous tree Quercus ilex. First, an increase in glucose content was observed in wounded plants. There was also an increase in the content of C-rich secondary metabolites such as quinic acid and quercitol, both related to the shikimic acid pathway and linked to defence against biotic stress. There was also a shift in N-storing amino acids, from leucine and isoleucine to asparagine and choline. The observed higher content of asparagine is related to the higher content of choline through serine that was proved to be the precursor of choline. Choline is a general anti-herbivore and pathogen deterrent. The study shows the rapid metabolic response of Q. ilex in defending its leaves, based on a rapid increase in the production of quinic acid, quercitol and choline. The results also confirm the suitability of 1H NMR-based metabolomic profiling studies to detect global metabolome shifts after wounding stress in tree leaves, and therefore its suitability in ecometabolomic studies.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Büker, P.</style></author><author><style face="normal" font="default" size="100%">Morrissey, T.</style></author><author><style face="normal" font="default" size="100%">Briolat, A.</style></author><author><style face="normal" font="default" size="100%">Falk, R.</style></author><author><style face="normal" font="default" size="100%">Simpson, D.</style></author><author><style face="normal" font="default" size="100%">Tuovinen, J.-P.</style></author><author><style face="normal" font="default" size="100%">Alonso, R.</style></author><author><style face="normal" font="default" size="100%">Barth, S.</style></author><author><style face="normal" font="default" size="100%">Baumgarten, M.</style></author><author><style face="normal" font="default" size="100%">Grulke, N.</style></author><author><style face="normal" font="default" size="100%">Karlsson, P. E.</style></author><author><style face="normal" font="default" size="100%">King, J.</style></author><author><style face="normal" font="default" size="100%">Lagergren, F.</style></author><author><style face="normal" font="default" size="100%">Matyssek, R.</style></author><author><style face="normal" font="default" size="100%">Nunn, A.</style></author><author><style face="normal" font="default" size="100%">Ogaya, R.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">Rhea, L.</style></author><author><style face="normal" font="default" size="100%">Schaub, M.</style></author><author><style face="normal" font="default" size="100%">Uddling, J.</style></author><author><style face="normal" font="default" size="100%">Werner, W.</style></author><author><style face="normal" font="default" size="100%">Emberson, L. D.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">DO3SE modelling of soil moisture to determine ozone flux to forest trees</style></title><secondary-title><style face="normal" font="default" size="100%">Atmospheric Chemistry and Physics</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">DO3SE</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Modeling</style></keyword><keyword><style  face="normal" font="default" size="100%">soil water</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal ozone ﬂux</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.atmos-chem-phys.net/12/5537/2012/</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">12</style></volume><pages><style face="normal" font="default" size="100%">5537 - 5562</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The DO3SE (Deposition of O3 for Stomatal Exchange) model is an established tool for estimating ozone (O3) deposition, stomatal ﬂux and impacts to a variety of vegetation types across Europe. It has been embedded within the EMEP (European Monitoring and Evaluation Programme) photochemical model to provide a policy tool capable of relating the ﬂux-based risk of vegetation damage to O3 precursor emission scenarios for use in policy formulation. A key limitation of regional ﬂux-based risk assessments has been the assumption that soil water deﬁcits are not limiting O3 ﬂux due to the unavailability of evaluated methods for modelling soil water deﬁcits and their inﬂuence on stomatal conductance (gsto), and subsequent O3 ﬂux. This paper describes the development and evaluation of a method to estimate soil moisture status and its inﬂuence on gsto for a variety of forest tree species. This DO3SE soil moisture module uses the Penman-Monteith energy balance method to drive water cycling through the soil-plantatmosphere system and empirical data describing gsto relationships with pre-dawn leaf water status to estimate the biological control of transpiration. We trial four different methods to estimate this biological control of the transpiration stream, which vary from simple methods that relate soil water content or potential directly to gsto, to more complex methods that incorporate hydraulic resistance and plant capacitance that control water ﬂow through the plant system. These methods are evaluated against ﬁeld data describing a variety of soil water variables, gsto and transpiration data for Norway spruce (Picea abies), Scots pine (Pinus sylvestris), birch (Betula pendula), aspen (Populus tremuloides), beech (Fagus sylvatica) and holm oak (Quercus ilex) collected from ten sites across Europe and North America. Modelled estimates of these variables show consistency with observed data when applying the simple empirical methods, with the timing and magnitude of soil drying events being captured well across all sites and reductions in transpiration with the onset of drought being predicted with reasonable accuracy. The more complex methods, which incorporate hydraulic resistance and plant capacitance, perform less well, with predicted drying cycles consistently underestimating the rate and magnitude of water loss from the soil. A sensitivity analysis showed that model performance was strongly dependent upon the local parameterisation of key model drivers such as the maximum gsto, soil texture, root depth and leaf area index. The results suggest that the simple modelling methods that relate gsto directly to soil water content and potential provide adequate estimates of soil moisture and inﬂuence on gsto such that they are suitable to be used to assess the potential risk posed by O3 to forest trees across Europe.</style></abstract><issue><style face="normal" font="default" size="100%">12</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sardans, J.</style></author><author><style face="normal" font="default" size="100%">Rivas-Ubach, A.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Factors affecting nutrient concentration and stoichiometry of forest trees in Catalonia (NE Spain)</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ecological stoichiometry</style></keyword><keyword><style  face="normal" font="default" size="100%">forest climate influence</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean forest</style></keyword><keyword><style  face="normal" font="default" size="100%">Tree nutrient relationships</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0378112711005111</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">262</style></volume><pages><style face="normal" font="default" size="100%">2024 - 2034</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Although some studies have observed signiﬁcant correlations between latitude and climate gradients and tree leaf nutrient concentration and stoichiometry, others have not. This study examined the nutrient concentrations of tree leaves in 3530 plots of the Catalonian Forest Inventory. Catalonia is a Mediterranean region located in NE Iberian Peninsula. It has a long land-use history and includes the large industrial-urban area of Barcelona but still contains a large forest area (42%). In the forests of Catalonia, leaf nutrient concentration increased and leaf C:nutrient ratios decreased from south to north, which paralleled the increase in MAP (mean annual precipitation) and the decrease in MAT (mean annual temperature), which was expected in a Mediterranean climate where the availability of water is the most limiting factor for plant nutrient uptake. In addition, the availability of water, which inﬂuences productivity, was associated with low leaf N:P content ratios, which is consistent with the Growth Rate Hypothesis. At a regional scale, the results support the Soil-Age Hypothesis because the youngest soils in the Pyrenees had the lowest leaf N:P ratios. Furthermore, the type of forest (evergreen, deciduous, or coniferous) explained some of the variation in leaf nutrient concentrations and stoichiometry. Nutrient concentrations were highest in deciduous trees and lowest in coniferous trees. Leaf nutrient concentrations and stoichiometry were mainly correlated with climate, but other factors such as the chemical properties of soil and rock, phylogenetics, and different ecological histories and anthropogenic factors such as pollution, had an effect.</style></abstract><issue><style face="normal" font="default" size="100%">11</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier B.V.</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">Alessio, G. a</style></author><author><style face="normal" font="default" size="100%">Ogaya, R.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Species-specific, seasonal, inter-annual, and historically-accumulated changes in foliar terpene emission rates in Phillyrea latifolia and Quercus ilex submitted to rain exclusion in the Prades Mountains (Catalonia)</style></title><secondary-title><style face="normal" font="default" size="100%">Russian Journal of Plant Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">isoprenoid emission</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">water stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1134/S1021443710061020</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">58</style></volume><pages><style face="normal" font="default" size="100%">126 - 132</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mediterranean vegetation emits large amounts of terpenes. We aimed to study the effects of the decreases in soil water availability forecast for the next decades by global circulation models and ecophysio logical models on the terpene emissions by two widely distributed Mediterranean woody species, Phillyrea latifolia L. and Quercus ilex L. We subjected holm oak forest plots to an experimental soil drought of ca. 20% decrease in soil moisture by partial rainfall exclusion and runoff exclusion. We measured the emission rates throughout the seasons for two years with contrasting precipitation and soil moisture (16.6% average in 2003 vs. 6.4% as average in 2005). Among the detected volatile terpenes, only αpinene and limonene were present in detectable quantities in all of the studied periods. Total terpene emitted ranged from practically zero (spring 2003) to 3.6 and 58.3 μg/(g dry wt h) (winter 2005 and summer 2003 for P. latifolia and Q. ilex, respec tively). A clear seasonality was found in the emission rates (they were the highest in summer in both species) and also in the qualitative composition of the emission mix. Maximum emissions of αpinene occurred in spring and maximum emissions of limonene in winter. Neither the interannual differences in water availabil ity nor the rain exclusion treatment significantly affected the emissions in P. latifolia, but Q. ilex showed by 17% lower emissions during the drier second year of study, 2005, but more than two and threefold increases with the drought treatment in summer 2003 and in summer 2005, respectively, showing historical accumu lated effects. These results, which show increased monoterpene emission under the moderate drought pro duced by the treatment and decreased emission under the severe second year drought, and a much higher sen sitivity to drought in Q. ilex than in P. latifolia, are useful in understanding the behavior of plant volatiles under Mediterranean conditions and in modeling future emission under changing climate conditions. They show that the usage of current models could lead to under and overestimations of the emission under summer dry conditions, because most current algorithms are based on light and temperature only.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Alessio, G. A.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">De Lillis, M.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Implications of foliar terpene content and hydration on leaf flammability of Quercus ilex and Pinus halepensis</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">fire</style></keyword><keyword><style  face="normal" font="default" size="100%">foliar hydration</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf flammability</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus halepensis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">terpene content</style></keyword><keyword><style  face="normal" font="default" size="100%">water content</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1438-8677.2007.00011.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">123 - 128</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We investigated the implications of foliar hydration and terpene content on leaf flammability in two widely distributed forest species of the Mediterranean basin, Quercus ilex, which does not store terpenes, and Pinus halepensis, a terpene-storing species. The experiments were carried out in plants grown under different water regimes that generated a wide range of foliar hydration and terpene contents. We monitored the temperatures and time elapsed to reach the smoke, pyrolysis and flame phases. Smoke appeared much earlier (37 versus 101 s) and at lower temperatures (96 versus 139 °C) in Quercus ilex than in Pinus halepensis. Quercus ilex reached pyrolysis earlier than Pinus halepensis (278 versus 338 s) but at the same temperature (365–371 °C). There were no significant differences in time elapsed nor in temperature for flammability (386–422 s; 505–487 °C in both species). Quercus ilex had lower water hydration than Pinus halepensis (41 versus 100%) and the leaf content of terpenes in Quercus was three orders of magnitude lower. The results of this study show no differences in the flame phase between the two species and the absence of a significant relationship between temperature and elapsed time of the different flammability phases in relation to monoterpene content; thus indicating that the role of monoterpenes in flammability phases is smaller than that of the water content. This, however, does not exclude the effects of terpene content on plant combustibility and fire propagation once fires start.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Alessio, G. A.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Ogaya, R.</style></author><author><style face="normal" font="default" size="100%">Estiarte, M.</style></author><author><style face="normal" font="default" size="100%">De Lillis, M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Influence of water and terpenes on flammability in some dominant Mediterranean species</style></title><secondary-title><style face="normal" font="default" size="100%">INTERNATIONAL JOURNAL OF WILDLAND FIRE</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Arbutus unedo</style></keyword><keyword><style  face="normal" font="default" size="100%">Cistus albidus</style></keyword><keyword><style  face="normal" font="default" size="100%">emission and content of volatile compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Erica multiflora</style></keyword><keyword><style  face="normal" font="default" size="100%">Globularia alypum</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus halepensis</style></keyword><keyword><style  face="normal" font="default" size="100%">Pistacia lentiscus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Rosmarinus officinalis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">17</style></volume><pages><style face="normal" font="default" size="100%">274 - 286</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In the Mediterranean basin, fires are a major concern for forest and shrubland ecosystems. We studied flammability, its seasonality and its relationship with leaf moisture and volatile terpene content and emission in the dominant species of a Mediterranean shrubland and forest in Catalonia ( NE Iberian Peninsula). We measured temperatures and time elapsed between the three flammability phases: smoke, pyrolysis and flame, for four seasons. We sampled twice in spring because of an occasional drought period during this season. Flammability had a significant relationship with leaf hydration, in the shrubland and in the forest. Few and only weak correlations were found between terpene content and flammability. In the future, arid conditions projected by climatic and ecophysiological models will increase fire risk through decreased hydration and subsequent increased flammability of the species.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: 150 OXFORD ST, PO BOX 1139, COLLINGWOOD, VICTORIA 3066, AUSTRALIA&lt;br/&gt;publisher: CSIRO PUBLISHING</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">ASENSIO, D.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">Ogaya, R.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal soil VOC exchange rates in a Mediterranean holm oak forest and their responses to drought conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Atmospheric Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean holm oak forest</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil CO2 flux</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil VOC exchange</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S1352231006004663</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">2456 - 2466</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Available information on soil volatile organic compound (VOC) exchange, emissions and uptake, is very scarce. We here describe the amounts and seasonality of soil VOC exchange during a year in a natural Mediterranean holm oak forest growing in Southern Catalonia. We investigated changes in soil VOC dynamics in drought conditions by decreasing the soil moisture to 30% of ambient conditions by artiﬁcially excluding rainfall and water runoff, and predicted the response of VOC exchange to the drought forecasted in the Mediterranean region for the next decades by GCM and ecophysiological models. The annual average of the total (detected) soil VOC and total monoterpene exchange rates were 3.273.2 and 0.470.3 mg m 2 h 1 , respectively, in control plots. These values represent 0.003% of the total C emitted by soil at the study site as CO2 whereas the annual mean of soil monoterpene exchange represents 0.0004% of total C. Total soil VOC exchange rates in control plots showed seasonal variations following changes in soil moisture and phenology. Maximum values were found in spring (1778 mg m 2 h 1 ). Although there was no signiﬁcant global effect of drought treatment on the total soil VOC exchange rates, annual average of total VOC exchange rates in drought plots resulted in an uptake rate (0.571.8 mg m 2 h 1 ) instead of positive net emission rates. Larger soil VOC and monoterpene exchanges were measured in drought plots than in control plots in summer, which might be mostly attributable to autotrophic (roots) metabolism. The results show that the diversity and magnitude of monoterpene and VOC soil emissions are low compared with plant emissions, that they are driven by soil moisture, that they represent a very small part of the soil-released carbon and that they may be strongly reduced or even reversed into net uptakes by the predicted decreases of soil water availability in the next decades. In all cases, it seems that VOC ﬂuxes in soil might have greater impact on soil ecology than on atmospheric chemistry</style></abstract><issue><style face="normal" font="default" size="100%">11</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Copolovici, L. O.</style></author><author><style face="normal" font="default" size="100%">Filella, I.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Niinemets, U.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The capacity for thermal protection of photosynthetic electron transport varies for different monoterpenes in Quercus ilex</style></title><secondary-title><style face="normal" font="default" size="100%">PLANT PHYSIOLOGY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">foliar photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">heat stress resistance</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex L.</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">139</style></volume><pages><style face="normal" font="default" size="100%">485 - 496</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Heat stress resistance of foliar photosynthetic apparatus was investigated in the Mediterranean monoterpene-emitting evergreen sclerophyll species Quercus ilex. Leaf feeding with fosmidomycin, which is a specific inhibitor of the chloroplastic isoprenoid synthesis pathway, essentially stopped monoterpene emission and resulted in the decrease of the optimum temperature of photosynthetic electron transport from approximately 38 degrees C to approximately 30 degrees C. The heat stress resistance was partly restored by fumigation with 4 to 5 nmol mol(-1) air concentrations of monoterpene alpha-pinene but not with fumigations with monoterpene alcohol alpha-terpineol. Analyses of monoterpene physicochemical characteristics demonstrated that alpha-pinene was primarily distributed to leaf gas and lipid phases, while alpha-terpineol was primarily distributed to leaf aqueous phase. Thus, for a common monoterpene uptake rate, alpha-terpineol is less efficient in stabilizing membrane liquid-crystalline structure and as an antioxidant in plant membranes. Furthermore, alpha-terpineol uptake rate ( U) strongly decreased with increasing temperature, while the uptake rates of alpha-pinene increased with increasing temperature, providing a further explanation of the lower efficiency of thermal protection by alpha-terpineol. The temperature-dependent decrease of alpha-terpineol uptake was both due to decreases in stomatal conductance, g(w), and increased volatility of alpha-terpineol at higher temperature that decreased the monoterpene diffusion gradient between the ambient air (F-A) and leaf (F-I; U=g(w)\{[\}F-A - F-I]). Model analyses suggested that alpha-pinene reacted within the leaf at higher temperatures, possibly within the lipid phase, thereby avoiding the decrease in diffusion gradient, F-A-F-I. Thus, these data contribute to the hypothesis of the antioxidative protection of leaf membranes during heat stress by monoterpenes. These data further suggest that fumigation with the relatively low atmospheric concentrations of monoterpenes that are occasionally observed during warm windless days in the Mediterranean canopies may significantly improve the heat tolerance of nonemitting vegetation that grows intermixed with emitting species.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><notes><style face="normal" font="default" size="100%">APSAPSThe following values have no corresponding Zotero field:&lt;br/&gt;pub-location: 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA&lt;br/&gt;publisher: AMER SOC PLANT BIOLOGISTS</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Serrano, L.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Contribution of physiological and morphological adjustments to drought resistance in two Mediterranean tree species</style></title><secondary-title><style face="normal" font="default" size="100%">Biologia Plantarum</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought stress</style></keyword><keyword><style  face="normal" font="default" size="100%">net photosynthetic rate</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">plant and tissue-water relations</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">water potential</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/pm645l6757200722.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">49</style></volume><pages><style face="normal" font="default" size="100%">551 - 559</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Plant water potential (ψ), its components, and gas exchange data of two Mediterranean co-occurring woody species (Quercus ilex L. and Phillyrea latifolia L.) were measured in response to seasonal changes in water availability over two consecutive years. The relative contribution of physiological and morphological adjustments to drought resistance was assessed through Principal Component Analyses. There were large adjustments in stomatal conductance (~36 % of accounted variance). Net photosynthetic rate and water use efficiency were closely tuned to water availability and accounted for ~17 % of variance. The slope of the water potential vs. relative water content (dψ/dRWC0) below zero pressure potential increased as a result of seasonal and ontogenic increases in apoplastic water fraction and accounted for ~20 % variance. This tolerance mechanism was accompanied by an increased range of positive pressure potential, suggesting a functional role of sclerophylly in these Mediterranean evergreens. Similarly, changes in the slope of dψ/dRWC in the range of positive pressure potential (~13 % of accounted variance) were associated to variations in cell wall elasticity and resulted in lower RWC at zero pressure potential. When considering the species studied separately, the results indicated the primary role of stomatal regulation in the drought resistance of Q. ilex, while increased apoplastic water fraction had a major contribution in the drought resistance of P. latifolia.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Oliveira, G.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of winter cold stress on photosynthesis and photochemical efficiency of PSII of the Mediterranean Cistus albidus L. and Quercus ilex L.</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Ecology</style></secondary-title><short-title><style face="normal" font="default" size="100%">Plant Ecol</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">evergreen</style></keyword><keyword><style  face="normal" font="default" size="100%">Fv/Fm</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean winter</style></keyword><keyword><style  face="normal" font="default" size="100%">photoinhibition</style></keyword><keyword><style  face="normal" font="default" size="100%">semi-deciduous</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005/01/01</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1007/s11258-005-4876-x</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">Kluwer Academic Publishers</style></publisher><volume><style face="normal" font="default" size="100%">175</style></volume><pages><style face="normal" font="default" size="100%">179-191</style></pages><isbn><style face="normal" font="default" size="100%">1385-0237</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">2</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">ASENSIO, D.</style></author><author><style face="normal" font="default" size="100%">MUNNÉ-BOSCH, S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Linking isoprene with plant thermotolerance, antioxidants and monoterpene emissions</style></title><secondary-title><style face="normal" font="default" size="100%">Plant, Cell &amp; Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">antioxidants</style></keyword><keyword><style  face="normal" font="default" size="100%">ascorbic acid</style></keyword><keyword><style  face="normal" font="default" size="100%">fumigation</style></keyword><keyword><style  face="normal" font="default" size="100%">Fv/Fm</style></keyword><keyword><style  face="normal" font="default" size="100%">high temperatures</style></keyword><keyword><style  face="normal" font="default" size="100%">isoprene</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthetic rates</style></keyword><keyword><style  face="normal" font="default" size="100%">thermotolerance</style></keyword><keyword><style  face="normal" font="default" size="100%">zeaxanthin</style></keyword><keyword><style  face="normal" font="default" size="100%">α-tocopherol</style></keyword><keyword><style  face="normal" font="default" size="100%">β-carotene</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1365-3040.2004.01250.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">28</style></volume><pages><style face="normal" font="default" size="100%">278 - 286</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The purpose of the present study was to test the possible plant thermotolerance role of isoprene and to study its relationship with non-enzymatic antioxidants and terpene emissions. The gas exchange, chlorophyll fluorescence, extent of photo- and oxidative stress, leaf damage, mechanisms of photo- and antioxidant protection, and terpene emission were measured in leaves of Quercus ilex seedlings exposed to a ramp of temperatures of 5 °C steps from 25 to 50 °C growing with and without isoprene (10 µL L−1) fumigation. The results showed that isoprene actually conferred thermotolerance (shifted the decrease of net photosynthetic rates from 35 to 45 °C, increased Fv/Fm at 50 °C from 0.38 to 0.65, and decreased the leaf area damaged from 27 to 15%), that it precluded or delayed the enhancement of the antioxidant non-enzymatic defence conferred by α-tocopherol, ascorbic acid or β-carotene consumption in response to increasing temperatures, and that it decreased by approximately 70% the emissions of monoterpenes at the highest temperatures. This suggests that there are inducible mechanisms triggered by the initial stages of thermal damage that up-regulate these antioxidant compounds at high temperatures and that these mechanisms are somehow suppressed in the presence of exogenous isoprene, which seems to already exert an antioxidant-like behaviour.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Science Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">Gimeno, B. S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal and species-specific response of VOC emissions by Mediterranean woody plant to elevated ozone concentrations</style></title><secondary-title><style face="normal" font="default" size="100%">ATMOSPHERIC ENVIRONMENT</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">biogenic VOCS</style></keyword><keyword><style  face="normal" font="default" size="100%">Ceratonia siliqua</style></keyword><keyword><style  face="normal" font="default" size="100%">Olea europaea</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex rotundifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">terpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">tropospheric ozone</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">36</style></volume><pages><style face="normal" font="default" size="100%">3931 - 3938</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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.</style></abstract><issue><style face="normal" font="default" size="100%">24</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND&lt;br/&gt;publisher: PERGAMON-ELSEVIER SCIENCE LTD</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal patterns of terpene content and emission from seven Mediterranean woody species in field conditions</style></title><secondary-title><style face="normal" font="default" size="100%">AMERICAN JOURNAL OF BOTANY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">alpha-pinene</style></keyword><keyword><style  face="normal" font="default" size="100%">limonene</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean woody species</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthetic rate</style></keyword><keyword><style  face="normal" font="default" size="100%">relative humidity</style></keyword><keyword><style  face="normal" font="default" size="100%">Seasonality</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">terpene emission and storage</style></keyword><keyword><style  face="normal" font="default" size="100%">volatility</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2000///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">87</style></volume><pages><style face="normal" font="default" size="100%">133 - 140</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The seasonal pattern of terpene content and emission by seven Mediterranean woody species was studied under field conditions. Emission rates were normalized at 30 degrees C and 1000 mu mol.m(-2).s(-1) PFD (photosynthetic photon Aux density). Bupleurum fruticosum, Pinus halepensis, and Cistus albidus stored large amounts of terpenes (0.01-1.77% \{[\}dry matter]) with maximum values in autumn and minimum values in spring. They emitted large amounts of terpenes (2-40 mu g.g DM-1.h(-1)), but with no clear seasonal trend except for Cistus albidus, which had maximum values in spring and minimum values in autumn. The nonstoring species Arbutus unedo, Erica arborea, Quercus coccifera and Quercus ilex also emitted large amounts of terpenes (0-40 mu g.g DM-1.h(-1)) and also tended to present maximum emission rates in spring, although this trend was significant only for A. unedo. At the seasonal scale, emission rates did not follow changes in photosynthetic rates; instead, they mostly followed changes in temperature. From autumn to spring, the least volatile monoterpenes such as limonene were emitted at highest rates, whereas the most volatile monoterpenes such as ol-pinene and P-pinene were the most emitted in summer. The monoterpene emission rates represented a greater percentage of the photosynthetic carbon fixation in summer (from 0.51% in Arbutus unedo to 5.64% in Quercus coccifera) than in the rest of the seasons. All these seasonality trends must be considered when inventorying and modeling annual emission rates in Mediterranean ecosystems.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: OHIO STATE UNIV-DEPT BOTANY 1735 NEIL AVE, COLUMBUS, OH 43210 USA&lt;br/&gt;publisher: BOTANICAL SOC AMER INC</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Short-term responses of terpene emission rates to experimental changes of PFD in Pinus halepensis and Quercus ilex in summer field conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental and Experimental Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">a-pinene</style></keyword><keyword><style  face="normal" font="default" size="100%">d 3 -carene</style></keyword><keyword><style  face="normal" font="default" size="100%">field conditions</style></keyword><keyword><style  face="normal" font="default" size="100%">limonene</style></keyword><keyword><style  face="normal" font="default" size="100%">pfd</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthetic rate</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus halepensis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Terpene emission</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1999///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0098847299000180</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">61 - 68</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The diurnal relationships of monoterpene emission with PFD and photosynthetic rates were studied in the Mediterranean trees Pinus halepensis, a terpene storing species, and Quercus ilex, a non-storing species, under summer ﬁeld conditions. At morning, midday and evening, leaves were submitted to different irradiance levels by differentially shading them. Both species emitted large amounts of monoterpenes (about 20 mg g DM1 h1 ). The most emitted terpene by P. halepensis was D 3 -carene followed by b-myrcene, a-pinene and b-pinene. The most emitted terpene by Q. ilex was limonene followed by a-pinene and b-pinene. No clear correlation to temperature was found for Q. ilex emission within the diurnal range of 21–33°C, whereas P. halepensis emissions increased with the temperature. There was no consistent link between terpene emissions and PFD or photosynthetic rates for P. halepensis but there were signiﬁcant relationships for Q. ilex. However, emissions by Q. ilex became inhibited at highest PFDs and during the course of the day when net photosynthesis decreased under summer drought. The study shows that the emission rates of both species are highly variable and that during a hot Mediterranean summer day (with limited water availability) the diurnal variation of emission is not only driven by the common light and temperature dependencies. Water stress, branch-to-branch variability and other inﬂuences must explain great part of the observed variability</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Changes in terpene content and emission in potted Mediterranean woody plants under severe drought</style></title><secondary-title><style face="normal" font="default" size="100%">Canadian Journal of Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean conditions</style></keyword><keyword><style  face="normal" font="default" size="100%">terpene concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">Terpene emission</style></keyword><keyword><style  face="normal" font="default" size="100%">Woody plants</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1139/b98-141</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">76</style></volume><pages><style face="normal" font="default" size="100%">1366 - 1373</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Terpene concentration and emission were studied in potted plants of some of the most common Mediterranean woody species (Pinus halepensis L., Pistacia lentiscus L., Cistus albidus L., Cistus monspeliensis L., Quercus ilex L., Quercus coccifera L., Phillyrea latifolia L., Phillyrea angustifolia L., and Arbutus unedo L.) under irrigation and under severe drought conditions that dropped relative water content to a range between 40% in Q. ilex and 85% in Phillyrea latifolia after withholding watering for one dry summer week. Terpene concentrations were detected in Pinus halepensis, Pistacia lentiscus, C. albidus, and C. monspeliensis, and they increased after withholding watering except in C. albidus. Terpene emission was detected in all species except Phillyrea angustifolia and A. unedo. Pinus halepensis showed the highest diurnal terpene emission rates of 86 µg·g-1 dry wt.·h-1 followed by C. albidus, Pistacia lentiscus, Q. ilex, Q. coccifera, Phillyrea latifolia, and C. monspeliensis (4 µg·g-1 dry wt.·h-1). Emitted terpenes represented from 0.33% of C fixed in C. monspeliensis to 10% in C. albidus. All species severely decreased their terpene emission rates under severe drought conditions. Emission by terpene-storing species (e.g., Pinus halepensis) was more related to temperature than in nonstoring species (e.g., Q. ilex), which showed emission relationships with photosynthetic rates. The monoterpenes alpha-pinene, beta-pinene, beta-phellandrene, and limonene and the sesquiterpene caryophyllene were the most abundant terpenes stored and emitted by these Mediterranean plant species.Key words: drought, Mediterranean conditions, terpene concentration, terpene emission, woody plants</style></abstract><issue><style face="normal" font="default" size="100%">8</style></issue><notes><style face="normal" font="default" size="100%">doi: 10.1139/b98-141doi: 10.1139/b98-141The following values have no corresponding Zotero field:&lt;br/&gt;publisher: NRC Research Press</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">Filella, I.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Siscart, D.</style></author><author><style face="normal" font="default" size="100%">Piñol, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Comparative field study of spring and summer leaf gas exchange and photobiology of the mediterranean trees Quercus ilex and Phillyrea latifolia</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Experimental Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">intrinsic water use efficiency</style></keyword><keyword><style  face="normal" font="default" size="100%">net photosynthetic rates</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">photochemical efficiency</style></keyword><keyword><style  face="normal" font="default" size="100%">photochemical reflectance index</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthetic radiation-use-efficiency</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">reflectance</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">summer</style></keyword><keyword><style  face="normal" font="default" size="100%">water index</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://jxb.oxfordjournals.org/content/49/319/229.abstract</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">49</style></volume><pages><style face="normal" font="default" size="100%">229 - 238</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Summer-induced changes in gas exchange, fluorescence and reflectance were measured on leaves of two co-occurring Mediterranean small trees, Quercus ilex and Phillyrea latifolia, in May, June and July 1996 in Central Catalonia (NE Spain). The humid 1996 summer only produced mild water stress conditions. However, photosynthesis (A) and stomatal conductance (gs) decreased in June and July in both species. In June P. latifolia had higher net photosynthetic rates and lower stomatal conductances than Q. ilex, thus exhibiting higher instantaneous plant water use efficiencies. In agreement with these results, the photo-chemical reflectance index (PRI, calculated as (R570-R531)/(R531+R570)) of P. latifolia was lower, suggesting a possible lower xanthophyll de-epoxidation state. However, P. latifolia had lower ΔF/F′ and therefore a lower electron transport rate (ETR). The behaviour of PRI confirmed previous studies indicating a strong relationship between PRI, ΔF/F′ , and photosynthetic radiation-use efficiency (PRUE). PRI offers a simple, portable means of assessing PRUE with the potential for remote sensing applications. Finally, the possible ecological consequences of these results on the behaviour of the two species studied under the predicted warmer and drier conditions of global change are discussed.</style></abstract><issue><style face="normal" font="default" size="100%">319</style></issue><notes><style face="normal" font="default" size="100%">10.1093/jxb/49.319.22910.1093/jxb/49.319.229</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Filella, I.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Piñol, J.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Leaf gas exchange and ﬂuorescence of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex saplings in severe drought and high temperature conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental and Experimental Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">hF/F’m</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthetic rate</style></keyword><keyword><style  face="normal" font="default" size="100%">Pistacia lentiscus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">39</style></volume><pages><style face="normal" font="default" size="100%">213 - 220</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Saplings of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex were witheld watering for 7 days, followed by reirrigation. Incident photosynthetic photon ﬂux density (PPFD), leaf temperature, net photosynthetic rates, stomatal conductance, and photochemical efﬁciency of the photosystem II (DF:F’m) were measured three times during the day. The watered plants had higher photosynthetic rates, stomatal conductances, DF:F’m and ETR than non-watered plants. However, watered plants were mildly water stressed as shown by low ratio of variable to maximal ﬂuorescence (Fv:Fm) and high non-photochemical ﬂuorescence quenching (qN). Their DF:F%m was low in the morning and increased in the evening, following the variations in PPFD. Watered plants of Q. ilex had lower photosynthetic activity, stomatal conductance and photosynthetic radiation use efﬁciency than Ph. latifolia and P. lentiscus, and, conversely, reached the highest DF:F%m and ETR. This seems to indicate a different relationship between photosynthetic activity and electron transport rate in Q. ilex compared to the other two species. Ph. latifolia and P. lentiscus appeared to be better adapted to severe drought than Q. ilex.</style></abstract></record></records></xml>