主成分分析法和稳定度指数法评价森林群落稳定性比较

Comparison of the analysis methods for forest community stability using principal component analysis and stability degree index methods

基于森林群落稳定性评价理论,以宝天曼国家级自然保护区内的栎类天然次生林群落为研究对象,选择反映森林群落抵抗力、恢复力、持久性的评价指标(共15个),构建主成分分析和稳定度指数评价模型,计算相应的综合评价值和稳定度指数,以此分别评价了群落稳定性,并对所得的结果进行了比较分析.结果表明,宝天曼地区栎类天然次生林群落总体处于稳定状态;对群落稳定性影响较大的指标为幼苗数量、林分密度和乔木物种多样性;两种模型评价结果都符合当地的森林群落发育情况,且在总体趋势上是一致的,但主成分分析法还可对评价指标的权重及其相互关系进行分析,评价过程可操作性强,具有较好的推广应用价值.

The forest community stability was evaluated by calculating comprehensive evaluation value and stability degree index based on forest community stability evaluation theory, choosing fifteen indices that describe community resistance, resilience and endurance and building principal component analysis and stability degree index evaluation model in oka natural secondary forest community of Baotianman nature reserve. The results showed that the oka natural secondary forest community was under stable condition in general in Baotianman area and the indices that influenced community stability more greatly was seedling numbers, stand density and arbor species diversity. The result of the two model evaluation was consistent with reality of local forest community and the gross trends, but principal component analysis method can also analyze the evaluation index weights and their mutual relationship. Whole process of evaluation in this model was easy to operate. Therefore, this model is worth extending its application in forest community stability judgment.