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CANOPY TRANSPIRATION
RESPONSE TO ENVIRONMENTAL VARIATIONS IN PLATYCLADUS ORIENTALIS:
PROPERTIES AND MODELLING
LEI HAN1,2,
KANGNING HE2*, XINGBO HU2 AND DONG ZHANG2
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.
1
New Technology Application and Research Center, Ningxia University,
Yinchuan 750021, China
2 College of Soil and Water Conservation, Beijing Forestry University,
Beijing 100083, China
*Corresponding author’s E-mail：shuibaoservice@163.com;
Tel:(+86)10 62338356; Fax: (+86)10 62338356
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