<?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%">Gimeno, Teresa E</style></author><author><style face="normal" font="default" size="100%">Pías, Beatriz</style></author><author><style face="normal" font="default" size="100%">Lemos-Filho, José P</style></author><author><style face="normal" font="default" size="100%">Valladares, Fernando</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Plasticity and stress tolerance override local adaptation in the responses of Mediterranean holm oak seedlings to drought and cold</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Adaptation</style></keyword><keyword><style  face="normal" font="default" size="100%">Biological</style></keyword><keyword><style  face="normal" font="default" size="100%">Biological: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Cold Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Droughts</style></keyword><keyword><style  face="normal" font="default" size="100%">eﬃciency</style></keyword><keyword><style  face="normal" font="default" size="100%">Freezing</style></keyword><keyword><style  face="normal" font="default" size="100%">Genetic Variation</style></keyword><keyword><style  face="normal" font="default" size="100%">Hot Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Nuts</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Photosynthesis: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Physiological</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Stress</style></keyword><keyword><style  face="normal" font="default" size="100%">thermal tolerance</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees</style></keyword><keyword><style  face="normal" font="default" size="100%">water</style></keyword><keyword><style  face="normal" font="default" size="100%">water use</style></keyword><keyword><style  face="normal" font="default" size="100%">Water: physiology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><volume><style face="normal" font="default" size="100%">29</style></volume><pages><style face="normal" font="default" size="100%">87-98</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Plant populations of widely distributed species experience a broad range of environmental conditions that can be faced by phenotypic plasticity or ecotypic differentiation and local adaptation. The strategy chosen will determine a population’s ability to respond to climate change. To explore this, we grew Quercus ilex (L.) seedlings from acorns collected at six selected populations from climatically contrasting localities and evaluated their response to drought and late season cold events. Maximum photosynthetic rate (Amax), instantaneous water use efficiency (iWUE), and thermal tolerance to freeze and heat (estimated from chlorophyll fluorescence versus temperature curves) were measured in 5-month-old seedlings in control (no stress), drought (water-stressed), and cold (low suboptimal temperature) conditions. The observed responses were similar for the six populations: drought decreased Amax and increased iWUE, and cold reduced Amax and iWUE. All the seedlings maintained photosynthetic activity under adverse conditions (drought and cold), and rapidly increased their iWUE by closing stomata when exposed to drought. Heat and freeze tolerances were similarly high for seedlings from all the populations, and they were significantly increased by drought and cold, respectively; and were positively related to each other. Differences in seedling performance across populations were primarily induced by maternal effects mediated by seed size and to a lesser extent by idiosyncratic physiologic responses to drought and low temperatures. Tolerance to multiple stresses together with the capacity to physiologically acclimate to heat waves and cold snaps may allow Q. ilex to cope with the increasingly stressful conditions imposed by climate change. Lack of evidence of physiologic seedling adaptation to local climate may reflect opposing selection pressures to complex, multidimensional environmental conditions operating within the distribution range of this species.</style></abstract><accession-num><style face="normal" font="default" size="100%">19203935</style></accession-num><notes><style face="normal" font="default" size="100%">10.1093/treephys/tpn007</style></notes><research-notes><style face="normal" font="default" size="100%">10.1093/treephys/tpn007</style></research-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%">Infante, Juan Manuel</style></author><author><style face="normal" font="default" size="100%">Mauchamp, André</style></author><author><style face="normal" font="default" size="100%">Fernández-Alés, Rocío</style></author><author><style face="normal" font="default" size="100%">Joffre, Richard</style></author><author><style face="normal" font="default" size="100%">Rambal, Serge</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Within-tree variation in transpiration in isolated evergreen oak trees: evidence in support of the pipe model theory</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">oak savannah</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">sap flow den- sity</style></keyword><keyword><style  face="normal" font="default" size="100%">water use</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2001</style></year></dates><volume><style face="normal" font="default" size="100%">21</style></volume><pages><style face="normal" font="default" size="100%">409-414</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Within-tree variation in sap flow density (SFD) was measured in two isolated evergreen oak (Quercus ilex L.) trees growing in an oak savannah (dehesa) in southwest Spain. Sap flow was estimated by the constant heating method. Three sensors were installed in the trunk of each tree in three orientations: northeast (NE), northwest (NW) and south (S). Sap flow density was monitored continuously from May 18 to September 27, 1993. Daily values of SFD ranged between 500 and 4500 mm3 mm−2 day−1. There were significant differences in SFD between orientations; SFD was higher in the NE and NW orientations than in the S orientation. These differences were noted on both a daily and seasonal time scale, and were less pronounced on cloudy days and at the end of the drought period, when SFD was relatively low. Our results support the idea that branches of trees can be viewed as a collection of small independent plants.</style></abstract><notes><style face="normal" font="default" size="100%">10.1093/treephys/21.6.409</style></notes><research-notes><style face="normal" font="default" size="100%">10.1093/treephys/21.6.409</style></research-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%">Sala, A</style></author><author><style face="normal" font="default" size="100%">Tenhunen, J D</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Simulations of canopy net photosynthesis and transpiration in Quercus ilex L. under the influence of seasonal drought</style></title><secondary-title><style face="normal" font="default" size="100%">Agricultural and Forest Meteorology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">canopy net photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Empirical model (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">water use</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><volume><style face="normal" font="default" size="100%">1</style></volume><pages><style face="normal" font="default" size="100%">203-222</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A mechanistically based C 3 leaf photosynthesis model combined with an empirical stomatal model and a canopy model of light interception and microclimate was used to simulate Quercus ilex canopy net photosynthesis and transpiration at l'Avic watershed (NE Spain). The model takes into account the sun-shade leaf differentiation of photosynthetic characteristics as affected by depth within the canopy. Based on field studies, simulations were carried out for two locations within the watershed along a gradient in elevation, microclimate and forest structure. Effective predictions of diurnal and seasonal courses of stomatal conductance of sun and shade leaves for different days during the year were obtained by changing a single model variable termed gF- The value of gF determined from least squares of observed vs. simulated time courses was linearly related to pre-dawn xylem water potential over critical ranges of the response curve. Response to gF in the model may to a great extent be thought of as the integrated expression of canopy response to root system generated signals or control mechanisms. For development of predictive capability, gF is extremely useful because it allows seasonal assessments of water use and carbon dioxide uptake with differing patterns in water availability. Based on simulated responses on representative clear, overcast and variable days throughout the year, only small differences in annual totals for net photosynthesis and transpiration were found between the two sites, despite large differences in soil drying. Annual estimates of canopy water loss were in close agreement with independent estimates of evapotranspiration using the hydrological input/output method.</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%">Valentini, R</style></author><author><style face="normal" font="default" size="100%">Scarascia Mugnozza, G</style></author><author><style face="normal" font="default" size="100%">De Angelis, P</style></author><author><style face="normal" font="default" size="100%">Matteucci, G</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Coupling water sources and carbon metabolism of natural vegetation at integrated time and space scales</style></title><secondary-title><style face="normal" font="default" size="100%">Agricultural and Forest Meteorology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">canopy conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">canopy photosynthesis (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon isotope discrimination</style></keyword><keyword><style  face="normal" font="default" size="100%">water use</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1995</style></year></dates><volume><style face="normal" font="default" size="100%">73</style></volume><pages><style face="normal" font="default" size="100%">297-306</style></pages><isbn><style face="normal" font="default" size="100%">3976135739</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The linkage between water utilization and photosynthetic processes is investigated using stable isotopes and eddy covariance techniques, allowing integration of physiological pro- cesses both at time and space scales, respectively. Using the ratio of the stable isotopes of hydrogen (hydrogen vs. deuterium) and discrimination of 13C vs. ~2C, the relationship between water sources (rain water vs. ground water) utilization and intercellular carbon dioxide con- centration is analysed for various species of two different ecosystems: an alpine forest and a Mediterranean macchia. As an example of space scale integration of water-carbon coupling, the relationship between canopy carbon dioxide assimilation and bulk stomatal conductance, measured with eddy covariance, is presented for a macchia community and a low-productivity grassland.</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%">Lillis, M</style></author><author><style face="normal" font="default" size="100%">Fontanella, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Comparative phenology and growth in different species of the Mediterranean maquis of central Italy</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Ecology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">mediterranean species</style></keyword><keyword><style  face="normal" font="default" size="100%">nutrient use</style></keyword><keyword><style  face="normal" font="default" size="100%">phenomorphology</style></keyword><keyword><style  face="normal" font="default" size="100%">water use</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1992</style></year></dates><volume><style face="normal" font="default" size="100%">99-100</style></volume><pages><style face="normal" font="default" size="100%">83-96</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A phenomorphological survey was carried out in central Italy to study the effects of increasing water stress on some characteristic species of the Mediterranean maquis. Nutrient content and leaf water potential were examined. The results show that three different groups exist which diverge in the mod- ulation of growth activity. 1) Evergreen sclerophyllous species (e.g. Pistacia lentiscus, Phillyrea media, Arbutus unedo, Ruscus aculeatus), which were supposed to be drought-tolerant, in fact limited their growth activity to a brief period before aridity increased. A similar growth pattern was exhibited by those spe- cies (e.g. Quercus ilex, Erica arborea, Smi/ax aspera) that stopped producing new leaves and branches during the driest season and that recovered after the first rain; i.e., their growth period lasted longer. 2) Drought-deciduous species (e.g. Calicotonw villosa) that adopted the drought-avoidance strategy had two vegetative periods interrupted by a phase during which they completely shed their leaves. 3) Semi- deciduous species (Cistus monspeliensis) with mesophitic leaves adopted an intermediate response. These grew even in the dry and cold season.</style></abstract></record></records></xml>