树种多样性计算方法的比较

Comparison of Tree Species Diversity Calculated

采用5种常用的物种多样性指数和基于相邻木空间关系的树种空间多样性指数(TSS),计算2类12种具有不同混交度的模拟林分和甘肃小陇山林区12种不同森林群落类型的树种多样性。结果表明:运用物种丰富度和相对多度的结合计算物种多样性,不同模型会得出不同的结论,调查数据的数目与群落中种的分布比例直接影响多样性计算结果,且Shannon-Wiener指数(H')和Simpson指数对稀少种并不敏感;基于相邻木空间关系的树种空间多样性指数(TSS)具有多样性随物种丰富度增大而增大的一般属性,不受调查株数和样地大小的影响,对稀少种敏感,且该指数能够正确表达出具有相同物种数量群落的树种空间隔离程度的大小,是一种良好的测度树种多样性的指数。

The five kinds of commonly used species diversity and the tree species spatial diversity based on the analysis of tree neighborhoods（TSS） were used to calculate the tree species diversity of the fictitious stand and empirical dataset.The fictitious stand used 2 kinds of 12 specifically designed patterns of spatial species mingling.The empirical dataset includes 3 field observations with known tree coordinates and 9 sample surveys from Xiaolongshan forest area.The results showed that the different models produced different conclusions by using species diversity calculated with species richness and relative abundance combination.The number of survey data and species distribution proportion in community directly influenced the calculated diversity.The Shannon-Wiener index and the Simpson index were not sensitive to the rare species.The value of the tree species spatial diversity（TSS） increased with increasing tree species richness,it was not subjected to the number of investigated trees and the size of plots,and was sensitive to rare species.TSS can properly express the size of the species spatial isolation in the communities with the same number of species,and is a good index measuring plant species diversity.