[Objective]Diameter and height class structure distribution of Parashorea chinensis Wang Hsie. plantations in different slope directions was analyzed to reveal the growth and development laws of P. chinensis,and provide reference for the selection of site conditions and the estimation on tree height of P. chinensis.[Method]Representative sample plots of P. chinensis plantations were respectively selected from north and south slope directions and every tree was measured. The upper limit exclusive method was used to divide the diameter and height class,and analyze the diameter and height class structure distribution in north and south slope directions. Six models including linear function,logarithmic function,quadratic function,power function,exponential function and Logistic model were used to fit the diameter at breast height(D)-plant height(H)curve.[Result]The differences of diameter class distribution of P. chinensis plantations were not obvious between the north and south slopes. Ⅵ diameter class on both north and south directions had the most numerous trees(32.00 cm≤D<36.00 cm),which accounted for 32.26% and 35.09% of the total respectively. As a whole,the distribution was normal distribution. The tree number was small in low and high diameter classes,and tree number was large in medium diameter class. The height class structure distribution in north slope of P. chinensis plantations presented normal distribution and the peak of height class distribution appeared at Ⅴ class(27.00 m≤H<30.00 m). While right-deviated normal distribution appeared in height class structure of P. chinensis plantations in south slope,with the peak of height class structure distribution at Ⅶ class(33.00 m≤H<36.00 m). It was obviously higher than the peak of height class in north slope. Power function H=3.096D0.656(R2=0.809)was the optimal equation to fit D-H of P. chinensis plantations in north and south slopes.[Conclusion]South slope has certain promoting effects on the plant height growth of P. chinensis plantations.The power function H=3.096D0.656(R2=0.809)can be used as D-H growth curve of P. chinensis plantations,which is used to select afforestation site and estimate plant height.%[目的]分析不同坡向望天树人工林的径级和高度级结构分布,揭示其生长发育规律,为望天树人工造林立地条件选择和树高估测提供参考依据.[方法]在北坡向和南坡向分别选取具有代表性的望天树人工林样地进行每木检尺,采用上限排外法划分径级和高度级,分析两个坡向的径级和高度级结构分布;使用线性函数、对数函数、二次函数、幂函数、指数函数和Logistic等6种模型拟合胸径(D)—树高(H)生长曲线.[结果]北坡向和南坡向望天树人工林的径级结构分布差异不明显,均在第Ⅵ径(32.00 cm≤D<36.00 cm)分布株数最多,分别占各坡向总株数的32.26%和35.09%,总体上呈正态分布,低、高径级株数较少,中等径级株数相对较多.北坡向望天树人工林高度级结构呈正态分布,在第Ⅴ高度级(27.00m≤H<30.00 m)出现峰值;南坡向望天树人工林高度级结构呈右偏正态分布,在第Ⅶ高度级(33.00 m≤H<36.00 m)出现峰值,且明显高于北坡向高度级峰值.对两坡向的望天树人工林胸径—树高曲线进行拟合,最优的是幂函数,其方程为H=3.096D0.656(R2=0.809).[结论]南坡向对望天树人工林树高生长具有一定的促进作用,幂函数H=3.096D0.656(R2=0.809)可作为望天树人工林树高—胸径生长曲线,用于树高估测和造林立地选择.
展开▼
