The Functional Space Characteristics Of Soil Microbial Of Forest Ecosystem In Northeast China

As the decomposer and consumer in nature, soil microorganism can be the driving force of the substance conversion and nutrient cycling in ecosystem, being the constituent part of the soil ecosystem. The distribution of soil microorganism is the response to the integrated effects of environmental factors including botany, soil and climate, at the same time the biological activity and species characteristics of them also can reflect the fertility of soil and the nutriture of plant. Therefore, soil microorganism can be the sensitive index of the change of the ecological environment, significantly contributing to the way of forest culture and management selection and the evaluation of the forest health. Focused on16soil sampling points in6nature reserve in the forest ecosystem of Eastern Chinese, this paper analyzed the species richness and the Shannon’s diversity index of plants and the total biomass of the plants and litters, and exploring the characteristics of soil physical and chemical properties and the spatial distribution of the functional genes of soil microorganisms with discussing the impacts of botany factor on the soil microorganisms. The main results are showed as follows:(1) The species richness of plants of the forests ecosystems in the Eastern China is high in South and low in North between the range from2to17, it was significant negative correlation with the latitude between41°31’-53°46’and the phosphorus content of soil, and was significant positive correlation with the relative water content of soil, soil organic carbon, organic matter, total nitrogen and Alkaline hydrolysis nitrogen, especially the mean annual temperature.(2) There are no obvious rules for the spatial characteristics of physical and chemical properties of soil based on the all kinds of index value from sample plots. However, the indexes of sample plots with high organic matter are higher, and vice versa.(3) The gene abundance and diversity index of macro genome of soil microorganism of the forest ecosystems in Eastern areas was significant positive correlation with latitude between41°31’-53°46’. The Shannon’s diversity index of macro genome of soil microorganism and functional gene (except the functional gene for nitrogen cycling) also were significant positive correlation with latitude. Besides, most of the secondary functional genes abundance and Shannon’s diversity index which involve with biochemical reaction were significant positive correlation with latitude.(4) The variation of relationship between the Soil microbial functional genes and plant factors can be explained respectively by the plant species richness(9.4%) and phytomass(8.2%) among all plant factors. The variation of relationship between the Soil microbial functional genes and edaphic factors can be explained respectively by the soil phosphorus content (6.1%) and Alkaline hydrolysis nitrogen content (3.2%) among all edaphic factors. The variation of relationship between the Soil microbial functional genes and climatic factors can be explained respectively by the annual precipitation(9.7%) and climatic factors (9.4%) among all climatic factors. Finally, there are some variations (40.1%) can not be explained.(5) According to the analysis of variance decomposition, the structural variation of functional gene of soil microorganism can be explained by plant factors(21.1%), edaphic factors(18.5%) and climatic factors(27.4%) respectively, and it also can be explained by the interaction of plant factors and edaphic factors(-3.75%), the plant factors and climatic factors(-0.7%), the edaphic factors and climatic factors(-0.8%) and the interaction of these three kinds of factors(--1.95%) respectively.(6) According to the analysis of Mantel correlation analysis, the functional gene of soil microorganism was significant positive correlation with the plant factors, the edaphic factors and the climatic factors.(7) According to the analysis of correlation analysis, the Shannon’s diversity index of macro genome of soil microorganism was significant negative correlation with the Plant species richness, total nitrogen content, alkaline hydrolysis nitrogen content and relative water content of soil, and the mean annual temperature. And it also was significant positive correlation with phosphorus content of soil and no significant correlation with the phytomass and annual precipitation.In total, the spatial distribution of soil microorganism is the result of the integrated impacts of the plant factors, the edaphic factors and the climatic factors It is quite complicated for the process of this impact. The final results indicate that there exits desynchrony between the diversity of functional genes of soil microorganism and those of plants.