秦岭西部山地次生林和人工林大型土壤动物群落结构特征

人类对次生林生态系统的长期扰动必然会对地下生态过程产生深刻影响,而土壤动物群落结构和功能多样性对地下生态过程的演变有重要的指示意义.本文以小陇山林区恢复近30年的次生林和栽植近30年的油松、日本落叶松、欧洲云杉和粗枝云杉林为对象,通过对5种林型土壤动物群落密度调查,采用PCA排序和方差分析等方法,探讨了不同林型土壤动物群落结构特征和营养结构.结果表明:油松林和日本落叶松林土壤动物群落密度是次生林的3.0和2.1倍；油松和日本落叶松人工林土壤动物群落中消费者/分解者比值明显高于次生林,油松林和日本落叶松林消费者/分解者的比值显著高于欧洲云杉林和粗枝云杉林；不同人工林土壤动物群落结构存在明显差异,油松林和日本落叶松林土壤动物群落密度是粗枝云杉林的4.5和3.1倍,而油松林土壤动物群落类群丰富度是欧洲云杉林和粗枝云杉林的1.5倍.

Characteristics of soil macrofaunal community structure in secondary forest and forest plantations in western Qinling Mountains of Northwest China

Long-term disturbance of human beings on secondary forest ecosystem would have profound impacts on belowground ecological processes,whereas the community structure and functional diversity of soil fauna would be sensitive to the changes of belowground ecological processes,with significance as an indicator of the changes.In this study,the method of hand-sorting was adopted to investigate the density of soil macrofaunal community in a secondary forest and the Pinus tabulaeformis,Larix kaempferi,Picea abie,and Picea asperata plantations of nearly 30 years old in Xiaolongshan forest area of western Qinling Mountains,and the PCA ordination and one-way ANOVA analysis were applied to analyze the community structure and trophic group composition of soil macrofauna in the five forest types.In the P.tabulaeformis and L.kaempferi plantations,the density of soil macrofaunal community was 3.0 and 2.1 times of that in the secondary forest,respectively,and the consumers/decomposers ratio of the community was obviously higher than that in the secondary forest.Among the plantations,P.tabulaeformis and L.kaempferi plantations had a significantly higher consumers/decomposers ratio of soil macrofaunal community than P.abies and P.asperata plantations.There was an obvious difference in community structure of soil macrofauna among the four plantations.The density of soil macrofaunal community in P.tabulaeformis and L.kaempferi plantations was 3.5 and 2.1 times higher than that in P.asperata plantation,respectively,whereas the group richness of soil macrofaunal community in P.tabulaeformis plantation was 1.5 times of that in P.abies and P.asperata plantations.