[Characterizations of soil enzyme activities and stoichiometry in three subtropical forest stands].

We conducted in a common garden experiment to explore the differences in soil enzyme activity, stoichiometry, and their influencing factors among a secondary forest, 10-year-old plantation, and plantation. The results showed that compared to the secondary forest, the soil organic carbon, total nitrogen, and dissolved organic carbon significantly decreased by 42.6%, 47.4%, and 60.9% in plantation, and by 42.9%, 36.7%, and 61.1% in plantation. Soil microbial biomass C, microbial biomass N (MBN), and microbial biomass phosphorus decreased significantly by 40.6%, 35.5%, and 45.9% in plantation, and by 53.7%、56.4%, and 61.7% in plantation. Compared to the secondary forest, soil enzymes activities in plantation did not change significantly, but in plantation, the activities of β-1,4-glucosidase and cellobiohydrolase significantly decreased by 51.2% and 59.8%, β--acetyl glucosaminidase and acid phosphatase decreased significantly by 41.0% and 29.8%, and enzymatic C:N acquisition ratio and enzymatic C:P acquisition ratio significantly decreased by 11.3% and 7.7%, respectively. Results of redundancy analysis indicated that MBN and NO-N were the primary factors influencing soil enzyme activity and enzymic stoichiometry. Collectively, there were significant differences in soil enzyme activity and microbial nutrient demands among different forest stands. Compared to secondary forests, the establishment of plantations would intensify nutrient competition between plants and microbes, and exacerbate the N and P limitations for microbes.