Change of Soil Enzyme Activity during the Process of Karst Forest Degradation in Central Region of Guizhou

The change of soil enzyme activity and relationship between enzyme activity and soil nutrient content during the process of forest degradation were studied to provide the theoretical basis for revegetation in Karst region with the frail ecosystem. The results showed that the soil pH was from neutrality to slightly alkalinity during the process degradation of Karst forest from original forest to secondary forest to bush forest to bush-grass land, and soil organic matter, alkalysis N, available P and activity of soil urease, peroxidase and alkalin phosphatase decreased obviously but the activity of proteinase and invertase was no difference. The activity of urease, peroxidase and alkalin phosphatase in low-growing bush soil decreased by 60%, 38% and 43% compared with virgin forest.