<?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%">Campos, Isidro</style></author><author><style face="normal" font="default" size="100%">Villodre, Julio</style></author><author><style face="normal" font="default" size="100%">Carrara, Arnaud</style></author><author><style face="normal" font="default" size="100%">Calera, Alfonso</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Remote sensing-based soil water balance to estimate mediterranean holm oak savanna (dehesa) evapotranspiration under water stress conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Hydrology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">Dual crop coefficient</style></keyword><keyword><style  face="normal" font="default" size="100%">Evapotranspiration</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean holm oak savanna</style></keyword><keyword><style  face="normal" font="default" size="100%">MODIS NDVI</style></keyword><keyword><style  face="normal" font="default" size="100%">water stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">Submitted</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0022169413003272</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Abstract This paper aims to present the use of a remote sensing-based soil water balance to estimate holm oak woodland evapotranspiration (ET). The model is based on the assimilation of MODIS reflectance-based vegetation indices in the dual crop coefficient methodology. A daily water balance was performed on the root zone soil to estimate plant water stress. The methodology was evaluated with respect to the actual ET measured by eddy covariance in Mediterranean holm oak savanna (dehesa) for five consecutive years (2004 to 2008). The model adequately reproduced the absolute values and tendencies measured at daily and weekly periods. Root mean square error (RMSE) was 0.50 mm/day for daily values and 2.70 mm/week for weekly accumulated values. The analysis demonstrated the presence of a long period of water stress during the summer and at the beginning of fall. Measured ET dropped during these periods, and the model replicated this tendency accurately, reaching a stress coefficient value close to 0.2. To be operative, the proposed method required low ground data (reference evapotranspiration and precipitation) and the results indicated a simple, robust method that can be used to map ET and water stress in the dehesa ecosystem.</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%">Dubbert, Maren</style></author><author><style face="normal" font="default" size="100%">Cuntz, Matthias</style></author><author><style face="normal" font="default" size="100%">Piayda, Arndt</style></author><author><style face="normal" font="default" size="100%">Máguas, Cristina</style></author><author><style face="normal" font="default" size="100%">Werner, Christiane</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Partitioning evapotranspiration – Testing the Craig and Gordon model with field measurements of oxygen isotope ratios of evaporative fluxes</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Hydrology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Craig and Gordon</style></keyword><keyword><style  face="normal" font="default" size="100%">evaporation</style></keyword><keyword><style  face="normal" font="default" size="100%">Evapotranspiration</style></keyword><keyword><style  face="normal" font="default" size="100%">Kinetic fractionation</style></keyword><keyword><style  face="normal" font="default" size="100%">Laser spectroscopy</style></keyword><keyword><style  face="normal" font="default" size="100%">Stable oxygen isotopes</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://www.sciencedirect.com/science/article/pii/S0022169413004083</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">496</style></volume><pages><style face="normal" font="default" size="100%">142 - 153</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">su mmary Stable oxygen isotopes of water provide a valuable tracer for water movements within ecosystems and are used to estimate the contribution of transpiration to total ecosystem evapotranspiration (ft). We tested the Craig and Gordon equation against continuous field measurements of isotopic composition of evaporation and assessed the impact for partitioning evapotranspiration. Therefore, evaporation (E) and its isotopic signature (d18OE) on bare soil plots, as well as evapotranspiration (ET) and its correspond- ing isotopic composition of (d18OET) of an herbaceous layer was measured with a cavity ring-down spec- trometer connected to a soil chamber on a field site in central Portugal. We quantified the variation in d18OE arising from uncertainties in the determination of environmental input variables to the Craig and Gordon equation: the isotope signature (d18Oe) and the temperature at the evaporating site (Te), and the kinetic fractionation factor (ak). We could hence quantify ft based on measured d18OET, modeled d18OE from observed soil water isotopic composition at the evaporating site (d18Oe), and modeled d18O of transpiration (d18OT) from observed total soil water isotopic composition. Our results demonstrate that predicting d18OE using the Craig and Gordon equation leads to good agree- ment with measured d18OE given that the temperature and 18O isotope profiles of the soil are thoroughly characterized. However, modeled d18OE is highly sensitive to changes in Te and d18Oe as well as ak. This markedly affected the partition results of transpiration and evaporation from the total ET flux: The frac- tion of transpiration (ft) varied strongly using different formulations for ak and assuming steady or non- steady state transpiration. These findings provide a first comparison of laser-based and modeled isotopic compositions of evaporation based on the Craig and Gordon equation under field conditions. This is of special interest for studies using stable isotopes to separate soil evaporation and plant transpiration fluxes and highlights the need for a thorough characterization of the micrometeorological and isotopic constitution of the upper soil layer to locate the evaporating front with a resolution of a few cm soil depths. We also call on a better characterization of the kinetic fractionation factor of soil evaporation.</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></authors></contributors><titles><title><style face="normal" font="default" size="100%">Intercepção da Precipitação em Árvores Isoladas de Quercus rotundifolia Lam</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%">Evapotranspiration</style></keyword><keyword><style  face="normal" font="default" size="100%">interception loss</style></keyword><keyword><style  face="normal" font="default" size="100%">montado</style></keyword><keyword><style  face="normal" font="default" size="100%">rainfall redistribution</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%">1 - 15</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=S0870-63522002000100001&amp;nrm=iso</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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.</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><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></records></xml>