中国长白山北坡土壤中小型土壤动物沿海拔梯度的群落组成及其空间分布

Composition and spatial distribution of soil mesofauna along an elevation gradient on the north slope of the Changbai Mountains, China

The Changbai Mountains, located in northeastern China, show clear vertical zonation of vegetation types. Six different habitats, namely Pinus koraiensis mixed broad-leaved forest, Pinus koraiensis-Picea forest, spruce-fir forest, Betula ermanii forest, alpine meadow and alpine semi-desert, at elevations ranging from 780 to 2 480 m, covering almost all ecosystems on the north slope of the Changbai Mountains, were investigated to determine: i) whether or not the community composition of soil mesofauna varied significantly at different elevations; ii) if different soil mesofauna groups would respond differently to elevation and iii) which factors influenced the spatial distribution of soil mesofauna along elevation. Soil mesofauna were collected from each habitat in spring (May), summer (July) and autumn (September) of 2009. The soil mesofauna communities were comprised of at least 44 groups and were dominated by Acari and Collembola, followed by Coleoptera, Diptera larvae and Enchytraeidae. The composition, diversity and abundance of soil mesofauna varied among the six habitats. Meanwhile, significant seasonal variations were observed in the composition, abundance and diversity of the soil mesofauna in each habitat. The taxonomic richness and Shannon index were affected by elevation and soil properties, while the abundance was only significantly affected by soil properties. With regard to taxa, the habitats and seasons had significant effects on almost all the abundances of the major taxonomic groups. The abundance of more taxonomic groups was significantly influenced by the soil properties, while those of Geophilomorpha, Araneae and other taxa were affected by elevation. It is concluded that the composition and spatial distribution of the soil mesofauna varied along the elevation gradient on the north slope of the Changbai Mountains, which might be largely related to the variations of the plant community, soil properties and climate change resulting from the elevation gradient.