<?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%">Pinto, Clara A.</style></author><author><style face="normal" font="default" size="100%">Nadezhdina, Nadezhda</style></author><author><style face="normal" font="default" size="100%">David, Jorge S</style></author><author><style face="normal" font="default" size="100%">Kurz-Besson, Cathy</style></author><author><style face="normal" font="default" size="100%">Caldeira, Maria C</style></author><author><style face="normal" font="default" size="100%">Henriques, Manuel O</style></author><author><style face="normal" font="default" size="100%">Monteiro, Fernando G</style></author><author><style face="normal" font="default" size="100%">Pereira, João S</style></author><author><style face="normal" font="default" size="100%">David, Teresa S</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Transpiration in Quercus suber trees under shallow water table conditions: the role of soil and groundwater</style></title><secondary-title><style face="normal" font="default" size="100%">Hydrological Processes</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cork oak</style></keyword><keyword><style  face="normal" font="default" size="100%">ecohydrology</style></keyword><keyword><style  face="normal" font="default" size="100%">sap flow radial profile</style></keyword><keyword><style  face="normal" font="default" size="100%">tree water sources</style></keyword><keyword><style  face="normal" font="default" size="100%">tree water use</style></keyword><keyword><style  face="normal" font="default" size="100%">water balance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><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%">Water is one of the major environmental factors limiting plant growth and survival in the Mediterranean region. Quercus suber L. woodlands occupy vast areas in the Iberian Peninsula, frequently under shallow water table conditions. The relative magnitude of soil and groundwater uptake to supply transpiration is not easy to evaluate under these circumstances. We recently developed a conceptual framework for the functioning of the root system in Q. suber that simulates well tree transpiration, based on two types of root behaviour: shallow connected and deep connected. Although this significantly improved knowledge on the functional traits of Mediterranean Q. suber, the approach has the limitation of requiring root sap flow data, which are seldom available. In this work, we present alternative methodologies to assess if trees are connected to groundwater and to estimate the soil and groundwater contributions to tree transpiration. We provide evidence on the tree unrestricted access to groundwater solely based on meteorological, stem sap flow and leaf water potential data. Using a soil mass balance approach, we estimated the yearly soil and groundwater contributions to tree transpiration: 69.7% and 30.3%, respectively. Groundwater uptake became dominant in the dry summer: 73.2% of tree transpiration. Results reproduce extremely well those derived from root modelling. Because of its simplicity both in formulation and data requirements, our approach is potentially liable to be adapted to other groundwater- dependent Mediterranean oak sites, where interactions between land use and water resources may be relevant.</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%">Nadezhdina, Nadezhda</style></author><author><style face="normal" font="default" size="100%">Vandegehuchte, Maurits W</style></author><author><style face="normal" font="default" size="100%">Steppe, Kathy</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Sap flux density measurements based on the heat field deformation method</style></title><secondary-title><style face="normal" font="default" size="100%">Trees</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Flow direction</style></keyword><keyword><style  face="normal" font="default" size="100%">Radial proﬁle</style></keyword><keyword><style  face="normal" font="default" size="100%">Sensor</style></keyword><keyword><style  face="normal" font="default" size="100%">Thermal gradient</style></keyword><keyword><style  face="normal" font="default" size="100%">tree water use</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><volume><style face="normal" font="default" size="100%">26</style></volume><pages><style face="normal" font="default" size="100%">1439-1448</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Accurate measurements of whole tree water use are needed in many scientiﬁc disciplines such as hydrology, ecophysiology, ecology, forestry, agronomy and climatology. Several techniques based on heat dissipation have been developed for this purpose. One of the latest developed techniques is the heat ﬁeld deformation (HFD) method, which relies on continuous heating and the combination of a symmetrical and an asymmetrical temperature measurement. However, thus far the development of this method has not been fully described in the scientiﬁc literature. An understanding of its underlying principles is nevertheless essential to fully exploit the potential of this method as well as to better understand the results. This paper therefore structures the existing, but dispersed, data on the HFD method and explains its evolution from an initial ratio of temperature differences proportional to vapor pressure deﬁcit to a fully operational and practically applicable sap ﬂux density measurement system. It stresses the importance of HFD as a method that is capable of measuring low, high and reverse ﬂows without necessitating zero ﬂow conditions and on several sapwood depths to establish a radial proﬁle. The combination of these features has not been included yet in other heat-based sap ﬂow measurement systems, making the HFD method unique of its kind.</style></abstract></record></records></xml>