Abstract:Paixichong watershed,a developed watershed in Deqing County,Zhejiang Province,was selected as a case to study the distribution characteristics of weed species richness in a watershed ecosystem in southern China‘s hilly area by using grid sampling method and combining GIS(Geographic Information System) technology.The results show that different land use patterns have a great impact on weed species composition and species richness distribution.The ecotone of paddy field and sloping land has the largest number...