檫树群落主要树种分布格局及其动态分析

Analyses of spatial distribution patterns and their dynamics of dominant trees in Sassafras tsumu community

采用7种聚集度指标测定方法研究了天然更新檫树〔Sassafrastsumu(Hemsl.)Hemsl.〕群落4个主要树种在不同取样尺度上的空间分布格局。研究结果表明,4个优势树种的空间分布主要呈聚集分布。在研究种群分布格局时,檫树种群的最适样方面积为100m2;丝栗栲(CastanopsisfargesiiFranch.)和拟赤杨〔Alniphyllumfortunei(Hemsl.)Makino〕种群的最适样方面积为50m2;光皮桦(BetulaluminiferaH.Winkl.)的最适样方面积为25m2。檫树和光皮桦种群在幼树、中树和大树阶段均为聚集分布;丝栗栲和拟赤杨在幼树及中树阶段为聚集分布,但聚集强度渐弱,到大树阶段即为随机分布。上述结果为调查研究中取样技术的确定提供了理论依据。

Using 7 aggregated indices to measure the spatial distribution pattern at different sample scales of 4 dominant populations in Sassafras tsumu (Hemsl.) Hemsl. community in natural regeneration forest. The results showed that the pattern of four dominant trees in S. tsumu community was mainly aggregated pattern. And when studing the spatial distribution pattern of population, the best sample area of S. tsumu population, Castanopsis fargesii Franch. population, Alniphyllum fortunei (Hemsl.) Makino population and Betula luminifera H. Winkl. population are 100, 50, 50 and 25 m2 respectively. The spatial distribution patterns of S. tsumu population and B. luminifera population at sapling tree, median tree and large tree stages are cluster; the patterns of C. fargesii population and A. fortunei population at sapling and median tree are cluster, and at large tree stage are random. While analyzing the effect of sampling factors on measured results, it offers the theoretical basis for sampling technique of forest survey.