Fire and Nutrient Cycling in Seral Grasslands of Cherrapunji in North-Eastern India

Abstract

Nutrient cycling under four grassland types of Charrapunji, one of the wettest spots of the world in north-eastern India, representing varied stages of arrested succession arising out of fire events was studied. More frequent fire reduced elemental quantities in the aboveground biomass than in the belowground parts. Under frequent burning, nutrient contents in the soil declined sharply and reached very low levels characteristic of highly desertified sites. Grasslands subjected to frequent fire had higher elemental turnover rates in the vegetation but lower rates in the soil. Under extreme desertification, the annual turnover rates for elements in the impoverished grassland was generally low. It is concluded that the initial perturbation impact on the forest ecosystem resulting in these arrested seral grasslands under exceptionally high rainfall is further exaggerated by fire effects on nutrient cycling properties.