<?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></contributors><titles><title><style face="normal" font="default" size="100%">Hydraulic Lift in Cork Oak Trees in a Savannah-Type Mediterranean Ecosystem and its Contribution to the Local Water Balance</style></title><secondary-title><style face="normal" font="default" size="100%">Plant and Soil</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><volume><style face="normal" font="default" size="100%">282</style></volume><pages><style face="normal" font="default" size="100%">361-378</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The aim of this study was to identify the sources and depth of water uptake by 15-years old Quercus suber L. trees in southern Portugal under a Mediterranean climate, measuring d 18 O and dD in the soil–plantatmosphere continuum. Evidence for hydraulic lift was substantiated by the daily ﬂuctuations observed in Ys at 0.4 and 1 m depth and supported by similar d 18 O values found in tree xylem sap, soil water in the rhizosphere and groundwater. From 0.25 m down to a depth of 1 m, dD trends diﬀered according to vegetation type, showing a more depleted value in soil water collected under the evergreen trees ()47&amp;) than under dead grasses ()35&amp;). The hypothesis of a fractionation process occurring in the soil due to diﬀusion of water vapour in the dry soil is proposed to explain the more depleted soil dD signature observed under trees. Hydraulically lifted water was estimated to account for 17–81% of the water used during the following day by tree transpiration at the peak of the drought season, i.e., 0.1–14 L tree )1 day )1 . Signiﬁ- cant relationships found between xylem sap isotopic composition and leaf water potential in early September emphasized the positive impact of the redistribution of groundwater in the rhizosphere on tree water status.</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%">David, Teresa Soares</style></author><author><style face="normal" font="default" size="100%">Ferreira, Isabel</style></author><author><style face="normal" font="default" size="100%">Pereira, João Santos</style></author><author><style face="normal" font="default" size="100%">Cohen, Shabtai</style></author><author><style face="normal" font="default" size="100%">David, Jorge Soares</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Transpiração em Árvores Isoladas de um Montado de Azinho: Evolução Sazonal e Condicionantes Hidráulicas</style></title><secondary-title><style face="normal" font="default" size="100%">Silva Lusitana</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">aquifer</style></keyword><keyword><style  face="normal" font="default" size="100%">Evapotranspiration</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus rotundifolia Lam.</style></keyword><keyword><style  face="normal" font="default" size="100%">sapflow</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%">10</style></volume><pages><style face="normal" font="default" size="100%">133 - 149</style></pages><isbn><style face="normal" font="default" size="100%">0870-6352 UL - http://www.scielo.gpeari.mctes.pt/scielo.php?script=sci_arttext&amp;pid=S0870-63522002000200001&amp;nrm=iso</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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</style></abstract><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: scielopt</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Transpiração em Árvores Isoladas de um Montado de Azinho: Evolução Sazonal e Condicionantes Hidráulicas</style></title><secondary-title><style face="normal" font="default" size="100%">Silva Lusitana</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2002</style></year></dates><publisher><style face="normal" font="default" size="100%">scielopt</style></publisher><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">133-149</style></pages><isbn><style face="normal" font="default" size="100%">0870-6352 UL - http://www.scielo.gpeari.mctes.pt/scielo.php?script=sci_arttext&amp;pid=S0870-63522002000200001&amp;nrm=iso</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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</style></abstract></record></records></xml>