Abstract:
Regrowth of tall, dense forests consumes more water, with the result that catchment yield may decline and even soil
desiccation occurred especially in the semi-arid Loess Plateau of China. In this study, meteorological measurements
combined with sap flow techniques provided a low-cost option to study the rates of water uptake by individual trees of
Platycladus orientalis response to environmental factors on a continuous basis. A series of environmental control
functions: vapour pressure deficit, solar radiation and air temperature were used to characterize canopy transpiration (Ec). A
Jarvis-type model, modified to directly estimate the Ec rather than canopy conductance, explained 89% of the variation
observed in Ec. Cross validation shows that this model provided good predictions of canopy transpiration for P. orientalis.
Such a methodology offers a reasonable estimation of water use in the determination of water balance for land water
resources planning, vegetation management and impact assessments of rehabilitation.
