广西杉木人工林生产力水热优化模型

以１９７９～１９９２年研究资料为基础，根据限制因子作用律建立广西杉木林生产力水热优化模型。模型表明，杉木生长最佳水热系数为２，３～２．６，广西杉木林生产力的宏观分布格局主要由温暖指数（即温度条件）所决定。采用主成分分析技术把广西杉木人工林生产力按不同水热组合环境划分为五大类型区，据此提出杉木速生高产林区的水热指标，并根据水热优化模型绘制了一系列广西不同海拔地带杉木林产量分布图，全面而定量地揭示了广西杉木林生产力三向地带性宏观格局。

THE HYDRO-THERMAL OPTIMUM MODEL OF THE PRODUCTIVITY OF THE CHINESE-FIR PLANTATION IN GUANGXI

This paper is written on the basis of 14 years' (1972-1992) research data. According to the functional rule of limiting factors, the hydro-thermal optimum models of productivity of the Chinese-fir plantation in Guangxi are set up as follows:The models indicate that the optimum hydro-thermal coefficient of Chinese-fir growth is from 2.3 to 2.6 and that the distribution pattern of Chinese-fir productivity in Guangxi is decided mainly by the warmth index (temperature condition) . Meanwhile, by using the principal component analysis, five groups of the productivity types of the Chinese-fir plantation in Guangxi are classified, according to the hydro-thermal combination environment. Then the hydro-thermal indexes of the fast-growth and high-yield Chinese-fir forest are proposed as follows: the yearly mean air temperature is 14.5-19.5℃, the monthly mean air temperature in July 20-28℃, the≥10℃ yearly accumulated temperature 5000-6700℃, and the yearly precipitation 1300-2000mm. This results are essentially the same as those reported by previous researchers. Finally, a series of Chinese-fir productivity distribution maps in different altitude zones in Guangxi are drawn according to the optimum models. These maps completely and quantitatively show the macro-patterns of three-direction zonation of the Chinese-fir productivity.