Effects of Re-vegetation on Soil Enzyme Activities and Soil Physio-chemical Properties on Sloping-land with Purple Soils in Hengyang City

[Objective]Study the effects of re-vegetation on soil enzyme activities and physio-chemical properties on sloping-lands with purple soils in Hengyang City,in order to reveal the change of soil property in different re-vegetation phases and the mechanism of recovery/degeneration of soil ecology.[Methods]Successional stages were postulated as those communities with different physiognomy,and in which soil samples of0—10cm,10—20cm and 20—40cm in plots of grassland(Ⅰ),frutex and grassplot(Ⅱ),frutex(Ⅲ),arbor and frutex community(Ⅳ)were collected.Some soil enzyme activities and physio-chemical properties in the postulated stages of re-vegetation were assayed and illustrated.[Results](1)Patrick richness index(R),Shannon—Wiener index(H)were followed the order as:ⅣⅡⅠ,Simpson index(D):ⅠⅡⅣⅢ,Evenness index(E):ⅣⅢⅡⅠ.The above and under-ground biomass significantly increased along revegetation;(2)SWC(soil water content),SOM(soil organic matter),TN(total nitrogen),TP(total phosphorus),NO-3—N(nitrate-nitrogen)and AP(available phosphorus)significantly increased along revegetation,whereas SBD(soil bulk density),pH values and R/Sratio(root/soil ratio)gradually decreased.Withthe increase of soil depth,SWC,R/Sratio,SOM,N and P significantly decreased,SBD and pH values gradually increased;(3)The activities of URE(Urease),PRO(protease),APE(alk-phosphatase),INV(invertase),CEL(cellulase)and PPO(polyphenol oxidase)significantly increased,and the activities of CAT(catalase)was the highest in Ⅲ.With the increase of soil depth,except for PPO and CAT,the activities of the other soil enzyme activities decreased obviously.[Conclusion]Re-vegetation could improve soil physiochemical properties and increase soil enzyme activities.