Abstract: Abstract：Soil enzyme is an important driving force for metabolic process of soil ecosystem,its change among soil layers and among plant communities can help us to understand the material cycle and energy conversion of soil ecosystem. In this study,four typical plant communities,i.e.Populus euphratica,Haloxylon persicum,Tamarix chinensis and [WTBX]Halocnemum strobilaceum communities,were set as the research subjects,and subsequently the variations of soil enzyme activities,i.e. catalase,urease,phosphatase and invertase,and the soil physicochemical properties and community quantity characteristics were investigated so as to reveal the relationships among them. The results are as follows: ① Soil enzyme activities were not significantly different among soil layers of 0-15,15-30 and 30-50 cm in depth in the four typical communities (P>0.05); ② There were no significant changes of activities of catalase and phosphatase among the four typical communities at the same soil depth (P>0.05), whereas the urease and invertase activities were opposite (P<0.05); ③ The results of multivariate linear stepwise regression revealed that there were little relations between the activities and community quantity characteristics for other soil enzymes except for the variation of catalase activity influenced by community quantity characteristics. In conclusion,soil physicochemical properties and community quantity characteristics can affect the changes of soil enzymes activity across soil layers and plant communities,however,the essential factors affecting soil enzyme activity was related to soil type.

Key words: soil enzyme activity, soil physicochemical property, community quantity, typical plant community, nature reserve, Ebinur Lake wetland