Comparison on composition and flora of shrubs between North and South of Xinjiang

Based on consulting of document and specimen,and field investigation,differences in species,composition and areal type of shrubs between North and South of Xinjiang were compared,similarity of shrubs between two regions was analyzed.The results show that there are 462 species of wild shrubs belonging to 127 genera of 39 families in Xinjiang,in which there are 350 species belonging to 104 genera of 37 families in North of Xinjiang and there are 160 species belonging to 63 genera of 28families in South of Xinjiang.The family number including 2-10 species is the most in shrubs of North and South of Xinjiang with 59.5% and 60.7% of total family number,respectively.And the common dominant families are Compositae,Leguminosae and Chenopodiaceae.The genera containing 1 or 2-10species predominate at genus level.The areal type of family of shrubs in both North and South of Xinjiang is mainly Cosmopolitan and N.Temp.types,in which number of family of these two areal types accounts for 43.2% and 32.4% of total family number of shrubs in North of Xinjiang and 50.0% and 28.6% of total family number of shrubs in South of Xinjiang,respectively.The areal type of genus of shrubs in both North and South of Xinjiang is mainly Mediterranea,W.Asia to C.Asia and N.Temp.types,in which number of genus of these two areal types accounts for 26.9% and 22.1% of total genus number of shrubs in North of Xinjiang and 31.7% and 27.0% of total genus number of shrubs in South of Xinjiang,respectively.Shrubs in North and South of Xinjiang contain 15 and 8 endemic species,respectively and moreover,contain some rare and endangered species and ancient relict species.Similarity coefficient of shrub flora between North and South of Xinjiang at family,genus and species levels is 86.1%,69.4%and 40.8%,respectively,showing that relationship of shrub flora at family and genus levels between two districts is closer.It is suggested that shrub species of North and South of Xinjiang are different in species composition,areal type,endemic number,etc.,while all have obvious temperate characteristics and form a series of survival strategy adapting to local ecological environment.