THE IMPACT OF DISTURBANCE ON DETRITAL DYNAMICS AND SOIL MICROBIAL BIOMASS OF A PINUS-KESIYA FOREST IN NORTHEAST INDIA

Detrital dynamics and microbial nutrient flux due to disturbances such as treefall and tree cutting were studied in a subtropical Pinus kesi ya Royle Ex. Gordon forest in north-east India. Disturbance has substa ntially altered community structure, and therefore soil nutrient statu s. Natural gap formation has not resulted in significant changes in dr y matter, C and N accumulation in litter and fine roots, or in microbi al nutrient concentrations. However, there was a significant reduction in all functional parameters in the selectively logged site and soil heap. Soil microbial C, N and P were maximum in the understorey and mi nimum in the heap. Fine roots and microbial biomass contributed more t o nutrient recycling in the ecosystem. N-mineralization was generally higher in the disturbed sites.