TY - JOUR
T1 - Diurnal dynamics of water transport, storage and hydraulic conductivity in pine trees under seasonal drought
AU - Klein, Tamir
AU - Cohen, Shabtai
AU - Paudel, Indira
AU - Preisler, Yakir
AU - Rotenberg, Eyal
AU - Yakir, Dan
N1 - KKL-JNF; Israel ministry of Agriculture; Sussman Center; Cathy Wills and Robert Lewis Program in Environmental Science of the Weizmann Institute; Israel ministry of Science (France-Israel High Council for Research Scientific and Technological Cooperation) [3-6735]; Minerva Foundation; Israeli Science Foundation (ISF); COST FORMAN (Forest Management and the Water Cycle) program [FP0601]
PY - 2016/10
Y1 - 2016/10
N2 - The temporal dynamics of water transport and storage in plants have major implications for plant functioning and survival. In trees, stress on the conductive tissue can be moderated by water storage. Yet, trees can survive high percent loss of conductivity (PLC, up to 80%), suggesting efficient recovery. We assess the role of tree water storage and PLC recovery based on simultaneous measurements of leaf transpiration, branch hydraulic conductivity, and stem sap-flow from different seasons in three study years in mature Pinus halepensis (Miller) trees in a semi-arid forest. During the wet season the rates of transpiration (T) and sap flow (SF) peaked at high morning and through the midday. During the dry season T peaked at ~9:00 and then decreased, whereas SF lagged T and fully compensated for it only in the evening, resulting in a midday water deficit of ~5 kg tree-1, and with up to 33% of daily T derived from storage. PLC of 30-40% developed during mid-day and subsequently recovered to near zero within 2-3 hr in the dry season (May, June, and September), but not in the wet season (January). The observed temporal decoupling between leaf water loss and soil water recharge is consistent with optimization of the trees’ water and gas exchange economy, while apparently facilitating their survival in the semi-arid conditions.
AB - The temporal dynamics of water transport and storage in plants have major implications for plant functioning and survival. In trees, stress on the conductive tissue can be moderated by water storage. Yet, trees can survive high percent loss of conductivity (PLC, up to 80%), suggesting efficient recovery. We assess the role of tree water storage and PLC recovery based on simultaneous measurements of leaf transpiration, branch hydraulic conductivity, and stem sap-flow from different seasons in three study years in mature Pinus halepensis (Miller) trees in a semi-arid forest. During the wet season the rates of transpiration (T) and sap flow (SF) peaked at high morning and through the midday. During the dry season T peaked at ~9:00 and then decreased, whereas SF lagged T and fully compensated for it only in the evening, resulting in a midday water deficit of ~5 kg tree-1, and with up to 33% of daily T derived from storage. PLC of 30-40% developed during mid-day and subsequently recovered to near zero within 2-3 hr in the dry season (May, June, and September), but not in the wet season (January). The observed temporal decoupling between leaf water loss and soil water recharge is consistent with optimization of the trees’ water and gas exchange economy, while apparently facilitating their survival in the semi-arid conditions.
UR - http://www.scopus.com/inward/record.url?scp=84991676991&partnerID=8YFLogxK
U2 - 10.3832/ifor2046-009
DO - 10.3832/ifor2046-009
M3 - مقالة
SN - 1971-7458
VL - 9
SP - 710
EP - 719
JO - IFOREST-BIOGEOSCIENCES AND FORESTRY
JF - IFOREST-BIOGEOSCIENCES AND FORESTRY
IS - 5
ER -