长白山典型天然林不同演替阶段物种多样性和结构多样性对生产力影响

Effects of species diversity and structural diversity on productivity in different succession stages of typical natural forest in Changbai Mountains of northeastern China

【目的】深入探讨物种多样性和结构多样性与生产力关系是科学提高森林生物多样性和生产力的重要前提,对森林经营具有一定的理论指导意义。本研究以长白山3块典型森林群落为研究对象,试图分析处于不同演替阶段的森林群落物种多样性和结构多样性与生产力之间的关系。【方法】利用长白山次生杨桦林、次生针阔混交林和原始椴树红松林代表群落演替的早、中、晚期,分别构建多元线性回归模型比较各个多样性指标与生产力的相关性,在此基础上选择表示物种多样性和结构多样性的最优指标,进而建立结构方程模型比较物种多样性和结构多样性对生产力影响的相对重要性。【结果】研究结果表明:演替早期,物种丰富度和胸径均匀度与生产力关系最为显著,二者对生产力的影响作用近似,但作用力不强;在演替中期,物种丰富度和胸径香农指数与生产力关系最为显著,二者均对生产力具有促进作用,且物种多样性对生产力的作用比结构多样性更强;演替晚期,物种多样性和结构多样性均与生产力没有显著的相关关系。【结论】长白山天然林群落物种多样性和结构多样性与生产力之间的关系与演替阶段有关,演替中期生态位互补作用显著,通过物种多样化组合和结构优化有助于促进群落生产力提升。

[Objective]Thoroughly exploring the relationship between species and structural diversity and productivity is an important prerequisite for the improvement of both forest biodiversity and productivity,and is of great significance for forest scientific management.In this study,three typical forest communities in Changbai Mountains of northeastern China were selected as the research object to analyze the relationship between species and structural diversity and productivity in different succession stages.The early,middle and late stages of communities were represented by the secondary poplar-birch forest,coniferous-broadleaved mixed forest and broadleaved Korean pine forest.[Method]Multiple regression models were built for the comparison of the correlations between different diversity indices and productivity,based on the regression results,the best index was determined to represent for species and structural diversity,and then the structural equation model was built to compare the relative importance of species and structural diversity on productivity.[Result]In the early succession stage,the relationship between species richness,DBH evenness and productivity was the most significant and the effects of these two diversity indices on productivity were similar but not strong.In the middle succession stage,the relationship between species richness,DBH Shannon index and productivity was the most significant,they both had positive effects on productivity,and the effects of species diversity on productivity was stronger than that of structural diversity.In the late stage of succession,there was no significant correlation between species diversity as well as structural diversity and productivity.[Conclusion]The relationship between species diversity as well as structural diversity and productivity of Changbai Mountains natural forest community is related to the succession stage,and the niche complementary effect is significant in the middle succession stage.Species diversity and structure optimization can improve community productivity.