Variation Law Of Plant Species Diversity In Xiaoxing'an Mountains Based On Spatiotemporal Dynamics

This study selected 5 small Xingan Mountain Forest National Nature Reserve,alpha and beta diversity of grass,birch,larch forest type diversity three latitude changes based on gradient based on the differences between the diversity of 5 National Nature Reserve in the succession of changes in forest type.Based on the quantitative evaluation method of species conservation value,the community structure and species composition of Nature Reserve were systematically analyzed,and the value of species conservation was evaluated scientifically.The results showed that:(1)with the increase of latitude,the Shannon Wiener index and Margalef index of grassland,birch forest and larch forest showed a decreasing trend.Dazhanhe protected areas of grassland,birch forest,larch forest relative to the other four latitude from north to south,Jaccard index and Sorenson index showed a decreasing trend,Cody index showed an increasing trend.The Jaccard index and Sorenson index showed peaks in the friendly area,and the species similarity was higher,indicating that the friendly region might be the ecotone of the small Xingan mountains.(2)5 National Nature Reserve from early successional to succession in the late Shannon Wiener index and Margalef index increased in later reached the maximum late succession began to decline,showed a single peak model,consistent with the mid species richness hypothesis.Reduce the Jaccard index and Sorenson index of Dazhanhe protected areas and protected areas of red pine forest friendly compared to the other 5 forest types were increased,indicating that there is a big difference between species composition and habitat environment of Pinus koraiensis and other forest types.(3)in the community were investigated in typical plant species in 76 families,205 genera and 371 species,the protection,the rare and endangered plants of 25 families 36 genera and 44species,community structure has the characteristics of monotonous,uniform characteristics and northeast flora,species with low degree of differentiation,mainly focus on the advantages of species.(4)friendly Forest National Nature Reserve T_P and T_Z index were higher in the first place,species conservation value,the protection of wild plants value red,Wuyiling nature reserve,although lower than the red star,Dazhanhe nature reserve,but the protection value of the rare species is higher than that of the latter,the protection of valuable rare species.