热平衡茎流仪测量精度及误差来源分析

Accuracy and Error Sources of the Stem Heat Balance Method in Sap Flow Measurements

目前国内借助热平衡技术开展荒漠植物蒸腾耗水的研究已十分普遍,但涉及测量精度与误差来源的分析研究鲜有报道。本文对茎干热平衡茎流仪监测植株茎流的基本原理进行了介绍,并在此基础上论述了茎干热平衡方法在实际应用中的测量精度及误差的主要来源,为使用热平衡茎流仪监测植物,尤其是荒漠植物提供参考。水分是干旱、半干旱区植物生长的主要限制因子。明确荒漠植物的需水与耗水规律可以为荒漠区生态环境建设过程中的植被种类选择、布局及管理提供科学依据。

Currently,it has been very popular that using the heat balance technique to estimate transpiring water-consumption of desert plants in domestic.However,researches on accuracy and error sources of the stem heat balance method were rarely reported.This paper firstly introduced the theory of stem heat balance technique,and then according to research results about application of heat balance stem flow gauge,pointed out accuracy and error sources of stem heat balance in practical application.Finally,several suggestions were put forward for sap flow measurement of desert plants,including controlling effect of environment temperature on stem temperature,reasonably determining value of Ksh,clearing the changing processes of dT and Qs.Water is a main limiting factor for plant growth in arid and semi-arid region.Understanding water requirement and consumption regulation of desert vegetation could provide scientific basis for the category selection,distribution and management of vegetation in the process of ecological environment construction.