Abstract: We analyzed the effects of hydrological management measures on soil enzyme activities (0-10 cm) and their driving factors during peatland restoration across natural peatland, restored peatland under different hydrological managements (high water level, alternating high-low water level, and low water level) and the degenerated peatland (abandoned land) in Changbai Mountains. The results showed that the activities of β-1,4-glucosidase and β-1,4-N-acetyl-glucosaminidase decreased from natural peatlands to restored peatlands to degraded peatlands. The activity of acid phosphatase in degraded peatlands was significantly lower than that in natural and restored peatlands, while the activity of polyphenol oxidase was the lowest in natural peatlands. In the restored peatlands, the activities of soil β-1,4-glucosidase, β-1,4-N-acetyl-glucosaminidase and acid phosphatase decreased gradually with the decreasing water level. However, the activity of soil polyphenol oxidase was the lowest in the restored peatlands under the hydrological management with alternating high-low water level. The activities of β-1,4-glucosidase andβ-1,4-N-acetylglucosaminidase were positively correlated with soil organic carbon content, water content, water level and total nitrogen content, and negatively correlated with pH and total phosphorus content. Soil acid phosphatase activity was positively correlated with soil water level, and negatively correlated with pH and total phosphorus content. Soil polyphenol oxidase activity was negatively correlated with soil organic carbon content, water content and total nitrogen content. Results of redundancy analysis showed that environmental factors explained 81.2% of the total variation in soil enzyme activities. Water level and soil organic carbon content were the main factors controlling soil enzyme activities. Our results indicate that appropriate hydrological management can effectively improve the contents of soil organic carbon, nitrogen and other nutrient elements and soil microbial enzyme activities of thedegraded peatlands, enhance soil ecological function, and accelerate the recovery of ecosystem function in peatlands.

Key words: Changbai Mountains, peatland restoration, soil enzyme activity, soil physicochemical property.