关键词: 杉木, 生产力, 水热因子, 优化模型, 主成分分析

Abstract: 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.

Key words: Chinese-fir, productivity, hydro-thermal factors, optimum model, principal component analysis