Ritam Dutta

Soil nematodes are among the most abundant and functionally important components of belowground biodiversity, regulating microbial dynamics, nutrient mineralization, carbon turnover, and soil food-web stability. However, the global consequences of climate and land-use change on nematode distributions and associated ecosystem vulnerability remain poorly understood. Here, we developed a global ensemble species distribution modelling framework integrating climatic, land-use, edaphic, topographic, and anthropogenic predictors to quantify present and future redistribution patterns of soil nematodes under coupled environmental change scenarios. A total of 6,685 occurrence records were compiled globally and spatially filtered to 1,772 independent locations. Ensemble models combining Random Forest, MaxEnt, and Generalized Linear Models demonstrated high predictive performance (ROC up to 0.93).,Our results identified mean temperature of the coldest quarter, thermal stability, and human footprint as dominant drivers shaping global nematode distributions. Temperate broadleaf and mixed forests consistently emerged as climatic refugia maintaining high suitability across future scenarios, whereas tropical moist forests and mangroves exhibited the highest ecosystem vulnerability, with Global Ecosystem Risk Index values ranging from 0.82-0.95 under SSP8.5 scenarios. Mangroves showed persistently elevated risk values (>0.90) across both future periods, indicating potential ecosystem tipping points. Tropical and subtropical moist broadleaf forests also exhibited high vulnerability (risk index 0.73-0.87), particularly across Amazonian, Central African, and Southeast Asian regions. In contrast, tundra and boreal systems exhibited severe projected ecosystem functional declines, with carbon losses reaching -177% and nitrogen mineralization declines up to -149% under combined climate and land-use scenarios.,The elasticity-based ecosystem risk analyses indicate that climate-driven redistribution of soil nematodes may substantially destabilize nutrient cycling and soil ecosystem functioning at planetary scales. Our findings highlight the urgent need to integrate belowground biodiversity into Earth system assessments, biodiversity forecasting, and climate-resilient land management strategies under accelerating global change.

Despite being considered one of the biodiversity hotspots, the mountainous region of Eastern Himalaya remains poorly studied due to difficult terrain, limited accessibility, and harsh climatic conditions. The present study used 50 camera traps for assessing the mammalian diversity in Tawang district of Arunachal Pradesh from September 2024 to June 2025. Among 50 camera traps, a single capture of the rare and elusive Clouded Leopard was recorded in a broadleaf forest at an elevation of 2,080 m on 28 January 2025, with additional records later obtained from two other camera locations in Tawang. This detection suggests a possible range extension of this globally vulnerable species in Tawang, Arunachal Pradesh, and corroborates earlier records from high-altitude areas of the state. Hence, the present study provides the baseline information on clouded leopard presence from the district. We suggest long-term monitoring and intensive camera trapping for the conservation and management of this threatened species.