关键词：
热平衡技术;多枝柽柳;茎干液流;叶干重;尺度转换
摘 要：
为了确定无灌溉多枝柽柳(Tamarix ramosissima Ledeb)人工林的耗水特性,运用热平衡茎流仪,监测了景泰县退耕还林地柽柳群落的枝干液流动态.同时,测定了柽柳冠幅、株高,分枝叶干重、基径、枝条长度和数量.结果表明:(1)柽柳茎干液流与叶干重极显著相关,在P<0.001水平上相关度R2达0.965,经叶干重标准化处理后可以很好地消除不同径级茎干液流间的差异.(2)以冠幅周长与株高建立的单株柽柳叶片总干重模型的平均精度达89.43%.在建立模型时依据灌木体积分级构建,可提高模型精度.(3)基于叶干重建立的柽柳单株耗水模型模拟值与实测值的平均误差为11.657%,可望准确估算柽柳耗水量.基于模型估算研究区柽柳生长季5-10月的累计耗水量约124.2 mm.
作 者：
LI Shuang;DU Jian-kuo;School of History and Tourism,Shaanxi University of Technology;
单 位：
LI Shuang%DU Jian-kuo%School of History and Tourism,Shaanxi University of Technology
关键词：
heat balance method;;Tamarix ramosissima Ledeb;;stem sap flow;;leaf dry weight;;scaling-up
摘 要：
In order to determine the transpiration characteristics of Tamarix Ramosissima Ledeb under no-irrigation condition in an arid environment,the Flow 32 heat balance gauge was used to monitor the sap flow of T. ramosissima Ledeb branches during growing season of2013 and 2014 in the transition zone between the Loess Plateau and the Tengger Desert. The plant biological parameters were also measured( e.g. leaf dry weight,crown perimeter,plant height,and so on). The results show that:(1) the stem sap flow is extremely proportional to its leaf dry height,and the relationship reaches a high significant level( P<0.001) with large determination coefficients( R2= 0.965). The sap flow difference of different stems can be eliminated well after standardized treatment by leaf dry weight.(2) Total leaf dry weight of individual shrub can be well measured through the crown perimeter and the plant height with a higher prediction accuracy of 89.43%. The precision of the model can be improved when considering the crown volume.(3) The average differences between measuring value and simulation value of the model is about 11.657%,suggesting that the scaling procedure can be used to provide reliable estimate of transpiration of the shrub T.ramosissima Ledeb. Moreover. Based on the estimating model,the mean water consumption of T. ramosissima Ledeb is about 124. 2 mm during a growing season.
