Relationships between soil enzyme activities in Kobresia humilis alpine meadow and soil properties.

The soil enzyme activities in Kobresia humilis alpine meadow was studied,and the relationships between soil properties and enzymes were analyzed.The results showed that from surface layer to 20cm in deepth,organic matter,total N,available N,total P,available P,available K and CEC decreased significantly while bulk density,pH,and total K increased.The activity of catalase,urease,protease,cellulase,invertase,and alkaline phosphatase decreased obviously along deepening of soil depth while polyphenol oxidase increased.The correlation analysis indicated that organic matter and available K were significantly negative with polyphenol oxidase,and significantly positive with the other enzymes measured in the study.Total N,available P,CEC showed obvious correlations with six enzymes except invertase.Available N,total K were significantly correlated with cellulase,alkaline phosphatase,etc.However,pH and total P did not show close relation with any enzymes.Polyphenol oxidase and invertase showed correlations with some of enzymes,while there were significant correlations between the other enzymes.Path analysis indicated that enzyme activities were controlled by interaction of soil enzymes and soil environmental factors through direct or indirect way.