Influence factors of species diversity of Picea crassifolia forest in Dongdahe forest area

Species diversity is an important index of forest community structure, composition and spatial feature. In the present study, the influence factors of species diversity of Picea crassifolia forest in Dongdahe forest area were analyzed with vegetation survey, species diversity analysis and correlation analysis. There were total 6 factors influence species diversity of P. crassifolia forest and their importance decreased in the following order: aspect, bryophyte coverage, soil bulk density and soil porosity, community types, canopy coverage. These factors had different ways to influence species diversity, for examples, the community characteristic directly affected the species diversity whereas the aspect indirectly affected species diversity by affecting the forest environment, soil type and characters. Bryophyte- P. crassifolia forest, higher canopy coverage, bryophyte coverage, soil porosity were not favor to increase species diversity. P. crassifolia forest had higher species diversity with 0.73~0.77 g·cm-3 soil bulk density, 68%~70% soil porosity, 0.6~0.7 canopy coverage and 14%～40% bryophyte coverage. For the different forest community types, species diversity of herb-P. creassifolia forest was higher than shrub-P. creassifolia forest and bryophyte-P. creassifolia forest. The multivariable regression model has been established for preliminary calculation of species diversity and the influence factor.