Xuzhou City, Secondary Forest Species Diversity And Niche Research

This paper researched the diversity and niche of secondary forest communities with mathematical method in limestone mountain areas in Xuzhou, Jiangsu Province.(1)This paper researched the diversity and niche of generated plants with mathematical method in limestone mountain areas in Xuzhou, Jiangsu Province.(2)The major 43 plant species in the ebinur belonged to 36genera,25 families,most plants blongs to ULMACEAE,MORACEAE,OLEACEAE,but more single species family in the layers.( 3 ) From all levels within the forest species composition,the oriental arborvitae trees in the layer still holds significant advantages,but in the shrub layer and layer of Seedlings and Saplings or missing,or the number of the very few on its natural regeneration more difficult.(4)Community diversity research showed that: there was a competitive relationship between the tree layer and bush layer, while there showed no competitive relationship between the bush layer and the sapling layer, which proved that the space utilization isn't saturated there, and the community succession is at prometaphase.( 5) The analysis of niche showed: Resource-niche which significantly influenced the species distribution of tree layer were pH value and available K content; for the bush layer the significantly influenced resource-niche is only the pH value; for the seedling and young tree layer the significantly influenced resource-niche is K content and hydrolysable nitrogen content. Broussonetia papyrifera, robinia pseucdoacacia, Acer buergerianum Miq and Morus alba L.got bigger niche breadth, which were suitable for the afforestation. The Koelrenteria Paniculata. ligustrum lucidum, pistacia chinensis, Grewia biloba G., Robinia pseudoacacia and Cortex Ulmi Parvifoliae can also be chosen as afforestation tree species.(6)Fallowing the results of the vertical structure of community divide,The analysis on niche breath of soil nutrients and soil moisture,this result has explained that the niche overlap of species are small ,but they can symbiosis and make an important role of species diversity restoration,which the latter utilize the resources discrepant in some degree.