Study On Community Structure And Species Deversity Of Picea Mongolica Mixed Forest In Duolun County

Based on investigation data of three transects of the Picea mongolia mixed forest in Duolun County, the authors measured the physical and chemical properties of the different soil depth (0～10cm,10～20cm,20～40cm,40～60cm,60～80cm,80～100cm) inside and outside of Picea mongolia mixed fores, studied the species composition, the age structure of dominant arbor population, diameter structure, height structure and spatial pattern of Picea mongolia and Betula platyphylla, analyzed and compared the species diversity of the communities of the Picea mongolia mixed forest. There is important ecological significance for understanding the soil nutrient deficiency, the development trend of the community of Picea mongolia mixed forest, the protection of biology diversity and ecological environment, also provided the reference for further study Picea mongolica mixed forest.The results showed that:1) The plant species of the Picea mongolia mixed forest was very rich in Duolun County, which were71kinds of plants in tree layer, shrub layer and herbaceous layer. The community vertical stratification structure was obvious.2) The content of soil organic matter, total N, total P and total K is mainly concentrated in the0～10cm soil depth; quickacting N, the content of quickacting P and quickacting K in0～20cm soil depth1inside of Picea mongolia mixed forest, while soil nutrient variation outside of Picea mongolia mixed forest is not obvious.3) The variation of the content of soil water content, organic matter, quickacting P of different slope inside of Picea mongolia mixed forest:the middle slope> the lower slope>the upper slope; the content of total N, total P, total K is mainly concentrated in the0～10cm soil depth, the variation of the content of total N, total P, total K:the middle slope>the upper slope>the lower slope; the variation of the content of quickacting K:the upper slope> the middle slope> the lower slope. The soil nutrient changes mixed forest showed a decreasing trend with increasing soil depth inside of the Picea mongolia, revealing the stand soil nutrients showed a declining trend.4) The stand diameter (height) structural distribution gradually reduced with the increased number of trees of diameter class (high class) in three transects of Picea mongolia mixed forest; The relationship of the Picea mongolia and Betula platyphylla between age and diameter at breast height was a positive correlation, compared with the diameter growth, the relationship between age and height variation is not obvious. The distribution pattern of arbor population and the dominant shrub population of three transects were clump.5) The species diversity of the Picea mongolia and Betula platyphylla mixed forest in Duolun County was rich, the gradient in the community, the community Ⅰ was52species, community Ⅱ was45species, community Ⅲ> was47species. The order of species index richness was that community Ⅰ>community Ⅲ>community Ⅱ.The index change of species diversity in the community was the same roughly, that was, herbaceous layer> shrub layer> tree layer. Species evenness index of tree layer in the community was the largest, shrub layer was smaller and herbaceous layer was the smallest.