Abstract:Soil enzyme is a crucial indicator of microbial metabolic activity and soil quality monitoring, playing an important role in the soil carbon and nutrient cycle. Global change could alter tree species composition, leading the transfer of dominant mycorrhizal at the individual or ecosystem level. In order to investigate the effect of mycorrhizal types on soil extracellular enzyme activity, four stands with percentage of different mycorrhizal type (the percentage of ECM trees was <25%, 25%-50%, 50%-75% and >75%, respectively) were set up in pure Cunninghamia lanceolata stand, pure Quercus acutissima stand, and the two species mixed forest. We measured the soil hydrolase activities[β-glucosidase (BG), β-N-acetylglucosaminidase (NAG), leucine aminopeptidase (LAP), acid phosphatase (AP)], and soil peroxidase (PER) activity and analyzed the pattern of hydrolase and oxidase activities along the gradient of mycorrhizal types using one-way ANOVA and multiple comparisons. The results showed that:① the regression slope of the ratio of lnBG to ln(NAG+LAP) and to lnAP were less than 1, indicating that AP activity was much higher than that of BG and NAG+LAP. This indicated that forest soil microorganisms were more severely restricted by phosphorus (P). The increase of ECM-associated tree species relieved the limitation of C and P for microorganisms. ② Soil organic carbon (SOC) increased as the proportion of ECM-associated tree species increased. While ECM-dominated forests had higher total soil nitrogen (TN) and total soil phosphorus (TP) contents than AM-dominated forests. ③ With the increase in the proportion of ECM-associated tree species in the forest, activities of BG, AP, and NAG+LAP showed a gradual increase trend (P<0.05)except for soil oxidase activity. ④ Soil hydrolase activity exhibited a significant correlation with ammonium nitrogen, nitrate-ammonium ratio, TN, TP, and SOC, while the oxidase activity only exhibited a significant correlation with the content of soil moisture (SM). These results support the theory of resource allocation, verify that the activity of soil extracellular enzymes changes gradually with the percent of AM-associated and ECM-associated tree species, and confirm the applicability of the mycorrhizal-associated nutrient economy pattern. The results also strengthen the predictability of the soil physical and chemical properties as well enzyme activities in the forest with different percentages of AM-associated and ECM-associated tree species, and thus contributing to the improvement of biogeochemical cycle model.