Unraveling the Vulnerability of Dry Tropical Grassland to Climate Change: A Case Study from an Asymmetrical Warming Experiment

Abstract

Tropical grasslands are vital ecosystems that support biodiversity, carbon balance, and food security. However, these ecosystems are thought to be increasingly vulnerable to climate change, particularly the asymmetric pattern of global warming, where day and night temperatures rise at different rates. This study explores the effects of nighttime warming (NW) and daytime warming (DW) on dry tropical grasslands due to limited studies. The response of DW and NW on aboveground processes has been reported from temperate or alpine ecosystems and is rare on belowground processes. Still, none of the studies are occurring in tropical ecosystems, especially in grasslands, that decipher how they change the belowground processes, specifically soil microbial communities and their functional attributes such as extracellular enzymatic activities. Therefore, we investigated the short-term effects of asymmetrical warming patterns (+0.9°C during daytime and +1.5°C during nighttime temperature treatment compared to the control) on soil microbial composition and their functional attributes through a controlled field experiment designed at the Botanical Garden of Banaras Hindu University campus, Varanasi. The present study showed that NW treatment caused more adaptable conditions for microbes than DW treatment, affecting nutrient dynamics, which might be a reason for differential shifts in microbial communities due to asymmetrical warming. These findings highlighted the consideration of asymmetric warming in climate models for better predictions of tropical grassland responses to climate change. This short-term study may be effective in developing conservation and management strategies and adaptive practices to mitigate global climate change impacts on belowground processes via microbial composition and their functional attributes in dry tropical grasslands. © 2026 selection and editorial matter, Sk Ajim Ali, Quoc Bao Pham, and Yunqing Xuan; individual chapters, the contributors.