SEASONAL DYNAMICS OF MICROBIAL BIOMASS-C, BIOMASS-N AND BIOMASS-P DURING REGROWTH OF A DISTURBED SUBTROPICAL HUMID FOREST IN NORTHEAST INDIA

Seasonal dynamics of microbial biomass C, N and P were studied in 7-, 13- and 16-year-old regrowths of a disturbed subtropical humid forest in north-east India. Microbial biomass C, N and P were highest during the winter and lowest during the rainy season at both the 0-10 and 10- 20 cm sample depths. The surface soil layer (0-10 cm) had significantl y higher microbial biomass C, N and P than the subsurface layer (10-20 cm). Microbial biomass C, N and P were highest in the 16-year-old reg rowth and lowest in the 7-year-old regrowth, coinciding with highest a nd lowest clay content and nutrient status of the soil in the 16- and 7-year-old regrowths, respectively. The C/N and C/P ratios in microbia l biomass showed a similar trend. Microbial biomass was negatively cor related with soil temperature and pH in all three regrowths.