林分空间结构指标研究进展

Research Progress on Indicators of the Stand Spatial Structure

林分空间结构指标是定量描述林分空间结构特征的指标,是林分空间结构研究的热点和难点问题。在分析林分空间结构单元研究现状的基础上,从林分树种隔离程度、林木竞争、林木空间分布格局、垂直结构4个方面综述了林分空间结构指数的研究动态,并指出目前采用n=4或普通Voronoi图构成的空间结构单元计算林分的空间结构指数的两种方法都存在缺陷,而将林木的胸径、树高和冠幅作为综合权重,生成加权Voronoi图确定空间结构单元能弥补前述两种方法的缺陷;采用单个林分空间结构参数来分析林分的空间结构某个特征或某个树种的整体特征,无法表达具有某类共同特征的林木微观结构。将空间结构参数两两联合后形成的联合概率分布,以三维空间形式展示林分空间结构将是未来林分空间结构分析的趋势。

Stand spatial structure indicators are defined as indexes to describe the features of forest spatial structure,which not only plays an important role in analyzing and controlling the forest structure and func-tion relationship,but also is the focus and difficult point in the research of stand spatial structure. The arti-cle was based on the analysis of the research status of stand spatial structure unit,summed up the research trends of stand spatial structure indicators from the spatial isolation of trees,tree competition,tree spatial pattern,stand vertical structure. Currently,the two methods used to calculate the forest stand spatial struc-ture index by using 4 or ordinary Voronoi diagram to constitute a space structural unit have some disadantages. But these disadantages can be offset when we generate a weighted Voronoi diagram with the diameter at breast height,tree height,and crown as comprehensive weight. Meanwhile,using a single stand spatial structure parameters to analyze a feature of the forest stand spatial structure or overall characteristics of a tree cannot express trees’microstructur if they have certain common characteristics. So it will be a future trend in stand spatial structure analysis,which will display stand spatial structure in three dimnsional space by using the joint probability distribution of the space structure parameters available together.