Research Projects

Tropical grassy biomes (TGB) host a rich diversity of flora and fauna including several endemic species, store 10-30% of the world’s soil carbon, contribute to 30% of the global net primary production and support one-fifth of the human population. But increasing frequency and intensity of extreme events like drought due to anthropogenic climate change and nutrient deposition due to human activities can alter the dynamics and distribution of grassy ecosystems and cause a decline in diversity, carbon uptake, plant productivity, soil retention and forage availability. However, most of our understanding of the ecological processes involved in community assembly and functioning of grasslands and their response to drought and nutrient deposition comes from temperate and alpine grasslands. TGBs differ from the temperate grasslands in terms of their evolutionary history and the factors shaping their community composition and function such as edaphic factors, climate and other disturbances. Although TGBs cover around 10% of India's land surface area, support multiple endemics, provide ecosystem services and support human livelihood, the impact of drought and nutrient deposition on grassy biomes remains poorly understood in Indian grasslands. Here I propose to test the effects of drought and nutrient deposition on the grasslands structure and function in the Deccan Peninsula across a rainfall gradient. As observed from earlier studies, drought and nutrient deposition are independently known to affect community structure and function in grasslands. However, their interactive effects are less well understood and can vary among sites, eg. Studies have shown that drought can cause a decline in annual net primary production (ANPP) whereas nutrient addition can increase ANPP but it can also increase sensitivity to drought causing a decline in ANPP. These factors also interact with local climate and disturbances and lead to differences in response in terms of structure and function among sites. I hypothesise that drought will result in a decrease in diversity and production and nutrient addition will decrease diversity and increase production in grasslands and both drought and nutrient addition will cause a functional shift in the grassland communities. I propose to set up a multi-site grassland experiment to study the effects of drought and nutrient addition in grasslands. I will use rainout shelters and add nitrogen and phosphorus fertilizers in a controlled amount in a randomised factorial design in multiple grassland sites varying in mean annual precipitation in the Deccan Peninsula region of Maharashtra for two growing seasons. Species richness, cover, functional traits and ANPP will be monitored in each treatment at each site annually. This study will give much-needed insights into the impact of these threats in the tropical grasslands of India and inform management practices in these grasslands.