Seasonal behaviour of carbon mineralisation kinetics, microbial biomass carbon and enzyme activities in three natural ecosystems of Kaziranga National Park, Assam, North East India

Abstract

Abstract Soil acts as an important source and sink for atmospheric carbon due to the activities of soil microorganisms. Any change on soil carbon cycle has a greater impact on the concentration of atmospheric carbon. These necessities the importance of soil biological parameters to predict the role of an ecosystem on carbon storage. However, there is dearth of information on seasonal dynamics of soil microbial properties and carbon mineralisation kinetics of semi-evergreen forests of North-east India that occupies about 25% of the countries forest cover. In this study, we collected soils from three natural ecosystems (grassland, forestland and wetland) of the Kaziranga National Park during pre-monsoon, monsoon and post-monsoon season for two consecutive years. In grassland and forestland ecosystem, soils were collected at two depths (0–15 cm) and (15–30 cm). The collected soils were analysed for soil microbial biomass carbon, extracellular enzyme activities and carbon mineralisation kinetics. The studied soil parameters significantly varied with season and ecosystem. However, this variation decreased with increasing soil depth. Conclusively, our findings documented that soil properties, microbial biomass carbon, extracellular enzyme activities, and carbon mineralisation kinetics significantly differ across the seasons and ecosystems of Kaziranga National Park. Further research is needed to explore the composition and function of soil microbial communities in different ecosystems over the seasons to accentuate our mechanistic comprehension of soil carbon dynamics of the studied ecosystems of Kaziranga National Park under changing climatic scenarios.