The impact of grazing on the activities of soil enzymes and soil environmental factors in alpine Kobresia pygmaea meadow

In order to determine the impacts of grazing on the soil enzyme activities and other environmental factors in alpine Kobresia pygmaea meadow,we investigated the activities of cellulase,polyphenol oxidase,urease,protease,alkali phosphatase,invertase and catalase,and the soil environmental factors.The results showed as follows: ①The vegetation coverage,above-ground biomass,soil organic matter,total nitrogen,NO3--N,total phosphorous,available phosphorous,water content decreased,while the underground biomass,bulk density,pH and root/soil ratio increased with grazing intensity.② The activities of most soil enzymes decreased with grazing intensity,while the catalase was higher in lightly grazing treatment than other treatments.③ The soil water content,underground biomass,root/soil ratio,soil organic matter and soil nitrogen and phosphorus decreased,while bulk density and pH increased with soil depth(P0.05). ④ Except for catalase and polyphenol oxidase,the activities of the other soil enzymes decreased obviously with soil depth.⑤The analysis of variance indicated that the characters of plant community,soil physical and chemical properties showed significant differences(P0.05),while only certain soil enzyme activities showed differences among different grazing intensity treatments.