萌生杉木林空间结构的二元分布特征

【目的】了解萌生杉木林林分整体的空间结构特征,为促进其结构优化提供理论参考。【方法】以浙江龙泉萌生杉木林为研究对象,采用空间结构参数二元分布分析林分及其优势树种杉木和木荷的空间结构特征。【结果】① 林分呈弱度混交向中度混交演变状态,空间格局为随机分布,不同大小比数等级的林木株数大致相等。随机分布状态的少数林木处于中庸状态,且劣态的林木株数多于优势木株数。② 杉木个体大多处于中低度混交状态,只有极少数处于高度混交状态。在同一混交等级上,不同优劣等级的林木株数差异较显著。③ 木荷的分布格局为随机分布,个体大多处于中庸和劣势木状态。【结论】研究区萌生杉木林分整体的混交度低,应进行密度控制,补植乡土树种,调整林分的格局为随机分布状态。

Bivariate distribution of spatial structure of a Cunninghamia lanceolate coppice forest

Objective] Explore the spatial structure characteristics of a Cunninghamia lanceolate coppice forest plot in Longquan City,Zhejiang Province,and to provide a theoretical basis for optimizing spatial structure of the study plot.Method] We conducted field investigations in the plot and used bivariate distribution of structural parameters to examine the spatial structure of C.lanceolate and Schima superbain this plot.Result] The results showed that:① The most tree individuals in this plot were randomly distributed and belonged to weak or moderate mingling degrees,trees with different neighbourhood comparison were approximately equal in number.Only a few trees in medium-sized state were randomly distributed.Moreover,the number of relatived disadvantaged trees was more than that of the advantaged trees.② Almost all the C.lanceolata trees were in moderate mingling degree,which indicated a very few individuals of the C.lanceolata were mixed with other species in the plot.On the same mingling degree,the trees in different dominance status have significant difference in number.③ S.superba was randomly distributed in the plot,and the most individuals were in the medium or disadvantaged status.Conclusion] These features revealed that the most tree individuals were lowly mixed in the study plot,to improve C.lanceolatae coppice forest toward random distribution and ideal structure,the stand density and the native tree species need to be adjusted through thinning and replanting.