作　　者： ; ; ; ;

机构地区： 韶关学院英东农业科学与工程学院

出　　处： 《生态环境》 2008年第3期1107-1111,共5页

摘　　要： 森林生态系统蒸散作为生态系统中的重要生态过程,联系着生态系统的水分平衡和能量平衡,并与养分循环密切相关。以雷州半岛桉树人工林纪家、河头林场为研究样地,在样地调查的基础上,对林地有关气象因子、土壤水文生态因子作了近4a的定位观测。选取TURC公式、Penman-Monteith方程(PM)和周国逸公式作为代表,三者分别以温度为指标、以辐射与能量转换为驱动因子和以物理过程为主导的蒸散量理论计算方法。并将理论计算结果同水量平衡法估算结果进行比较。结果表明,尽管各种计算方法的结果均存在一定的波动性,但是其波动的原因是不一样的。对于PM方程而言,结果对所选参数有一定的依赖性。对于周国逸公式来说,在计算较小时间尺度(≤1a)蒸散量时可能会出现一定的波动,波动的原因可能在于参数的时间尺度匹配问题。对于TURC公式,计算结果波动的根本原因在于其公式的经验局限性。理论计算值同水量平衡估算结果比较说明,三者均可以在一定程度上反映系统的年蒸散量。比较而言,周国逸公式计算结果的波动性范围较小,较适用于热带、亚热带森林生态系统蒸散量的计算。 Evapotranspiration, a major component in terrestrial water balance and net primary productivity models, is difficult to measure and predict. This study compared three equations of potential evapotranspiration applied to the eucalypt forest plantations on Leizhou Peninsula in southern China. The evapotranspiration models ranged frorn simple ternperature and solar radiation-driven equations to physically-based combination approaches, represented by Turc formula, Penman-Monteith equation and Zhou equation. Each calculation of evapotranspiration was compared with estimation from water balance budget equation （WB）. The deviation rate between calculations by the three equations and WB yielded coefficients of variation of-2.5% to 34.0%, -19.3% to 9.2%, -4.0% to 19.1% for Turc formula, Penman-Monteith equation, and Zhou equation, respectively. Fluctuations in overall estimated result from complex changes of climatic parameters and in situ conditions. The reason of fluctuations for the three models was different from each other. The parameter-dependant sensitivity may result in fluctuation for Penman-Monteith equation, while the time scale matching may be a major factor in fluctuation for Zhou＇s equation. And the fluctuation for Turc formula may result from extra emphasis on temperature factor, not accounting for any local factors such as precipitation patterns and soil hydro-physical properties, which may be a limitation of empirically-based model. The calculations from each model are in good agreement with the annual evapotranspiraton of the eucalypt plantations estimated from water balance budget equation to some extent. By comparison, the fluctuation from Zhou＇s equation was less than those from the other two equations, which indicated the Zbou＇s equation was more suitable alternative for Penman-Monteith equation for the determination of evapotranspiration of forest ecosystems in the subtropics of south China.

关 键 词： 雷州半岛 桉树人工林 蒸散量 理论计算

领　　域： [生物学]