In order to reveal the difference of soil quality in different forest slope positions from the biological view,this study investigated the seasonal changes of soil enzyme activities and microbial biomass at different slope positions of apple grove in Chunhua county on the Loess plateau.The results indicated that soil enzyme activities,microbial biomass were significantly affected by slope positions(P<0.05).The urease,invertase and alkaline phosphatase activities were in the order:lower slope> upper slope>mi...