Subham Banerjee

The decline of grasslands and savanna due to woodland encroachment is a matter of global concern. In the Terai-Duar Savanna and Grassland ecoregion (hereafter terai), located at the base of the Himalayas in the Indian subcontinent, there are indications that grasslands and savanna are being lost, with unknown consequences for biodiversity and ecosystem function. We assessed large-scale vegetation changes in terai eight large protected terai habitats over three decades (1989-2019) and quantified the environmental and anthropogenic drivers of the observed changes using Bayesian Conditional Autoregressive spatial models. Notably, very little grasslands remain and the initial extent of 1417 km2 declined to 923 km2 (34.4%) in 30 years. Woodland area increased from 3235 km2 to 3516 km2 (8.7%). Dry season grass fire had the strongest influence on grassland persistence, followed by anthropogenic impacts. Terai ecosystems also experience significant threats from climatic changes and increasing human footprint, particularly in India.

Conserving landscape connections among favorable habitats is a widely used strategy to maintain populations in an increasingly fragmented world. A species can then exist as a metapopulation consisting of several subpopulations connected by dispersal. Our study focuses on the importance of human–wildlife coexistence areas in maintaining connectivity among primary habitats of small ungulates within and outside protected areas in a large landscape in central India. We used geospatial information and species presence data to model the suitable habitats, core habitats, and connectivity corridors for four antelope species in an ~89,000 km² landscape. We found that about 63% of the core habitats, integrated across the four species, lie outside the protected areas. We then measured connectivity in two scenarios: the present setting, and a hypothetical future setting—where habitats outside protected areas are lost. We also modelled the areas with a high risk of human-influenced antelope mortality using eco-geographical variables and wildlife mortality records. Overall, we found that the habitats in multiple-use forests play a central role in maintaining the connectivity network for antelopes. Sizable expanses of privately held farmlands and plantations also contribute to the essential movement corridors. Some perilous patches with greater mortality risk for species require mitigation measures such as underpasses, overpasses, and fences. Greater conservation efforts are needed in the spaces of human–wildlife coexistence to conserve the habitat network of small ungulates.