Research Projects

Widespread land use and land cover (LULC) changes across the world have led to large-scale conversion of forests and grasslands to human-dominated ecosystems such as agricultural lands, grazing lands, and urban areas. Such a rapid transformation of land, in particular of vegetation and soils, is expected to have wide-ranging impacts, including significant changes to the terrestrial carbon cycle, biodiversity loss of most taxa, and the decline of ecosystem services. Here we focus on a unique ecoregion in the Indian subcontinent, called the Terai-Duar Savanna and Grasslands ecoregion (henceforth TDSG), which occurs as a narrow belt (25 km North-South width) across almost the entire East-West range at the base of the Himalayas. It is a region of high ecological and economic importance, forms an important buffer between the Himalayan ranges to the north and the great plains to the south, and hosts diverse ecosystems including forests, savanna, and grasslands. Increasing areas of natural ecosystems are being transformed into agricultural lands and other human-dominated land uses, leaving very few intact habitats (~20% of land area) for the numerous endemic and habitat specialist species of flora and fauna. Here we consider the largest relevant east-west extent of this ecoregion (Fig. 1) and aim to understand the LULC changes that have taken place in the last 40 years (based on satellite data availability), and to study the consequences of these changes for terrestrial carbon cycling, plant biodiversity and vegetation structure. We quantify LULC changes using extensive remote-sensing data, examine the environmental and socioeconomic drivers of the these changes using rigorous land use change models. We also examine potential future trajectories of LULC changes. Next, we will study terrestrial carbon cycling by quantifying aboveground and belowground plant biomass, soil organic carbon (SOC), and the important SOC physical fractions of particulate and mineral-associated carbon forms. Sampling for plant diversity, plant biomass, and SOC in four clusters of sites across the region, we will carry out our work using combinations of field methods, laboratory analyses, and landscape ecological modelling. Finally, we will study how plant diversity is affected by LULC changes, and how these changes in plant diversity and vegetation structure are linked to terrestrial carbon cycling. We will develop plant diversity distributions for the region by combining primary field sampling with extensive published secondary data and using correlations with environmental variables. We propose to develop a precise method to detect and quantify subtle transitions between forest, savanna, and grasslands and study the drivers of these transitions, which is an important attribute of this region. This proposed work will involve rigorous work in three domains – field ecological sampling, laboratory analyses, and landscape ecological modelling.