Research On Plant Species Diversity Of Water Conservation Forest And Its Relationship Withsoil Nutrients In Liaodong Mountains

Using the method of space substititing for time, the plant species diversity of plant communities in different recovery stages and its relationship with soil nutrients were studied in Laotudingzi national nature reserve of Liaoning province. The species diversity at herbaceous layer, shrub layer and tree layer and the overall were analyzed useing indices of Patrick, Shannon-Wiener, Pielou and Simpson. The niche breadths and niche overlaps of main species of communities were computed according to Shannon-Wiener coefficients (H) and similarity percentage. Moreover, the correlations beween pH, organic matter, total nitrogen and available nitrogen of soil and the plant species diversity were dicussed. The results showed:1. The species diversity showed that herb layer> shrub layer> tree layer. The largest plant diversities appearedin the herb layer of the Adenophora divaricata and Glycine soja community in the shrub layer of Populus Davidiana forest and in the tree layer of Populus Davidiana-Quercus mongolica community. Taking all plant species together, The largest plant diversity appeared inthe Populus Davidiana-Quercus mongolica communityand the smallest plant diversity appeared in the highest community stage.2. Ecological niche breadths and overlap of Quercus mongolica, Acer pseudo-sieboldianum, Populus davidiana and Acer mono in tree layers were high. The species ecological niche breadths of shrub layers and herb layers were generally greater than0.1and the species with high niche breadth have high ecological niche overlap among them.3. In the vegetation restoration process of water conservation forest in Liaodong mountain near riparian, soil organic matter, total nitrogen and available nitrogen decreased with increase of the soil depth, while the soil pH increased with increase of the soil depth. Soil pH of each soil layer of Betula platyphylla-Populus Davidiana was highest than other communities, and was a slight acid. Soil organic matter, total nitrogen and available nitrogen were the highest in Acer-Queens mongolic forest.4. Patrick and Shannon-Wiener indices had positive correlation with soil nutrients indexes, the correlations between Patrick index and topsoil organic matter, total nitrogen of suface layer were sigrrficant (p<0.05), plant species dominance and evenness had negative correlation with pH and had positive correlation with other soil nutrients indexes.