Seasonal dynamics in soil microbial biomass C, N and P in a mixed-oak forest ecosystem of Manipur, North-east India

The soil microbial biomass C, N and P were studied in two stands of mixed-oak forest ecosystem of Manipur, North-east India to assess the influence of abiotic variables and difference in forest stand on the seasonal variation in soil microbial biomass. Microbial biomass C, N and P were highest during rainy season and lowest during winter in both the forest stands with the exception of microbial N which was lowest in summer in stand II. Microbial biomass C and P showed a positive significant correlation with abiotic variables, i.e. soil moisture, soil temperature, rainfall, mean air temperature and relative humidity in both the stands. Whereas the microbial N exhibited a positive significant correlation with abiotic variables in stand I, but showed a significant correlation only with soil moisture in stand II. The contribution of microbial C, N and P to total soil organic C, total N and P indicates that microbial biomass is immobilized more in forest stand I in comparison to forest stand II.