Characteristics Of Soil Faunal Community Among Zonal Vegetation Types On The Northern Slope Of Changbai Mountains

Changbai Mountain is the beginning area of studying soil fauna in our conuntry,but the studying progress is slow. In July 2009 we studied soil fauna and related environmental factors of 6 vegetation types (Alpine semi-desert , Alpine tundra , Betula ermanii , Fir-spruce coniferous forest , Pinus fir-spruce coniferous forest and Mixed coniferous broad leaved forest) of Changbai Mountains, in order to reveal the community characteristics and distribution of soil fauna at different altitudes and its influencing factors.On north-facing slope of Changbai Mountain we got 41 groups total 10077, belonging to 2 phyla, 6 classes, 15 orders and 41 families. The dominant groups were Oribatida, Isotomidae and Pseudachorutidae, the common groups were Enchytraeidae, Gamasida, Actinedida and Hypogastruridae. The remaining 34 groups were rare groups. Dominant groups and the common groups take accounted for 93.91% of soil fauna. These groups distribute widely, have a strong ability to adapt to environmental change, form the major component of soil fauna in the northern slope of Changbai Mountains.There were some differences between the compositions of soil fauna communities in different vegetation types. The dominant group of macro-soil fauna in 6 vegetation types was Enchytraeidae, Isotomidae was the only dominant group of micro-soil fauna that 6 vegetation types all has. The composition of common and rare groups in different vegetation types was quite different. The general trend was the number of individuals and groups reduces, the complexity of community structure reduces, the dominance reduces while evenness increases, with altitude increasing. Shannon-Wiener index, Pielou index and Margalef index of Mixed coniferous broad leaved forest were high; Shannon-Wiener index and Margalef index of Alpine semi-desert and Alpine tundra were low, while Simpson index was high.Vertical distribution of soil fauna on northern slope of the Changbai Mountain compliance to this law that individuals and groups diminishing with the soil depth increasing. Groups of all 6 vegetation types were richer in litter layer and the 0-5cm layer, of which the most abundant macro-soil fauna was mixed coniferous , while sub-alpine tundra was lowest. Mixed coniferous broad leaved forest and Fir-spruce coniferous forest have the most abundant micro-soil fauna, while sub-alpine tundra was lowest. This indicates that the soil fauna in the low altitude has the phenomenon of surface accumulation, while in the high altitude areas soil fauna tend to distribute in deep soil layers.The results of Pearson correlation shows that, the individuals of soil fauna shows a significant positive correlation with the soil total nitrogen, soil total phosphorus and soil organic matter content,while groups has less relationship with soil factors. The individuals and groups of soil fauna have a positive correlation with the soil total nitrogen and soil organic matter content, have less relationship with soil total phosphorus. All soil fauna show no positive correlation with the soil Ph. Specific to each vegetation types, the correlation between soil fauna and soil factors was varied. Overall, the differences between habitats has more obvious impact on macro-soil fauna than the micro-soil animals.