Classification And Analysis Of Soil Factor For Aeluropus Littoralis Var. Sinensis Community In Songnen Grassland

Soil is an are important ecological factor in ecosystem.The physical and chemical properties difference of soil will greatly affect the growth of plants,and consequently affect the species composition and spacial distribution of plant community.Based on the investigation data of the Aeluropus littoralis var.sinensis community from Songnen Grassland and the five soils factor:organic matter,available phosphorus,available nitrogen,pH values and electric conductivity,the dissertation studied the correlation between environment factors and Aeluropus littoralis population phenotypic characteristics,and classified the Aeluropus littoralis community.The results provide useful references for deeply understanding of the ecology mechanism that soil heterogeneity affect plants community characteristics in Songnen Grassland.Based on sampling in field and analyzing in laboratory,the Aeluropus littoralis community were classified with cluster analysis method,the influence of soil factors on Aeluropus littoralis community distribution were analyzed by DCA and CCA ordination methods,the changing trends of Aeluropus littoralis community species density changing with soils factors were studied by trend-surface analysis method which combined DCA and GAM model.The investigation conclusions are as followings:Based on heterogeneity of soils factors,Aeluropus littoralis community can be classified into four types:Aeluropus littoralis and Leymus chinensis community, Aeluropus littoralis and Phragmites australis community,Aeluropus littoralis and Artemiaia anethiflia community,Aeluropus littoralis and ruderal community.The results of DCA and CCA ordination methods are approximately the same. Organic matter and comprehensive effects of available phosphorus and available nitrogen are main soils factors that influence Aeluropus littoralis community distribution,While pH electric and conductivity rate have small influence on it.On the base of ordination methods,the trend surface Aeluropus littoralis conducted with GAM model.Contour maps were presented which reflected each species changes with the two ordination axis,and expressed the changing trend of species density affected by the two main environment factors.The results showed:(1)With increasing of organic matter contents in soils,the density of Aeluropus littoralis and Suaeda salsa decreased gradually,but the density of Leymus chinensi and Scirpus planiculmis increased.(2)With enhancing of comprehensive effects of available phosphorus and available nitrogen,the density of Phragmites australis and Setria viridis increased at first and then decreased, the density of Chloris virgata,Polygonum sibiririm and Limonium bicolo showed the trends of increasing,and the density of Artemisia anethoicle and Artemiaia anethiflia decrease all the time.