Relationship of soil fauna and N cycling and its response to N deposition
土壤动物与N素循环及对N沉降的响应

This paper reviews based on available scientific knowledge the importance of soil fauna for N cycling and its response to N deposition. The functioning of terrestrial ecosystems depend highly on soil fauna biodiversity, which have characteristic impacts on ecosystem processes. N is usually a limited nutrient element for plant growth, and is also the quantitatively most important mineral element absorbed by plants from the soil. But the supply of N by turnover in the ecosystem fully depends on biological soil processes. The diversity of soil fauna is large and has important impact on this N turnover. It is suggested that 30 percent of N mineralization is due to the action of soil fauna, and the percentage is even higher under the action of macrofauna. Many soil fauna, such as earthworm, termite and enchytraeid can accelerate N mineralization rate significantly. The diversity of functional groups is important in the research of the effect of soil fauna community on N mineralization, but taxonomic diversity's effects are not significant. It is also recovered that soil fauna can enhance the efficiency of N absorption by plants, however, the mechanism of which is not known yet. N deposition is a serious environment problem globally. It changes soil physical and chemical characteristics, the quality of food, the mutual role of community, and even kill soil life forms directly. As a result, the diversity of soil fauna and its function in the ecosystem is affected by N deposition. The research methods used in studying soil fauna and N turnover, the impact and its mechanism of soil fauna on N turnover, and the responses of soil fauna to N deposition is discussed in this paper. The demands for soil fauna research in the tropic of N turnover and impact N deposition is outlined. .