Western Ghats Biodiversity Atlas Published After Decade-Long Field Survey

Landmark Atlas Published After Ten-Year Survey

The Zoological Survey of India and the Botanical Survey of India jointly released the Western Ghats Biodiversity Atlas today, a six-volume publication representing the most exhaustive scientific inventory of one of the world's eight hottest biodiversity hotspots. The atlas, produced by 340 field researchers from 22 Indian research institutions over ten years of continuous fieldwork, documents 9,400 species spanning mammals, birds, reptiles, amphibians, freshwater fishes, vascular plants, and select invertebrate groups.

Among the atlas's most significant findings is the formal documentation of 18 vertebrate species new to science — five freshwater fish species from the Periyar and Chaliyar river systems, seven amphibians from high-altitude shola grassland patches in the Nilgiris and Anamalai hills, three lizard species, and three small mammals from the montane evergreen forests of northern Kerala.

Threat Assessment: 34 Per Cent of Range Under Pressure

Beyond taxonomic documentation, the atlas contains a geospatial threat assessment indicating that approximately 34 per cent of the Western Ghats' ecologically sensitive range faces moderate to high anthropogenic pressure from agricultural encroachment, plantation expansion, linear infrastructure projects, and human settlement growth. The assessment uses satellite imagery from 2013 and 2023, giving researchers a precise decade-long comparison of canopy cover and land-use change.

Hotspots of concern include the connectivity corridors between the Anamalai Tiger Reserve and the Parambikulam Landscape in Kerala-Tamil Nadu, where road widening projects have created movement barriers for elephants and large felids, and the northern section of the Sahyadri mountain range, where rapid urbanisation around Pune and Nashik has fragmented historically contiguous forest patches.

Policy Implications

The Gadgil Committee had famously recommended in 2011 that the entire ecologically sensitive zone of the Western Ghats receive the highest level of protection, a recommendation that was subsequently diluted and controversially revised by the Kasturirangan Committee. Researchers involved in the atlas have called on the government to use the new dataset to revisit the ESZ mapping, particularly for areas where the new atlas data reveals previously undocumented species concentration.

The atlas is available as an open-access digital resource, with interactive species distribution maps and downloadable data layers, enabling state forest departments, academic researchers, and environmental planners to integrate the findings directly into environmental clearance evaluations and wildlife corridor planning. The Union Ministry of Environment, Forests and Climate Change described the atlas as an invaluable foundation for science-based conservation planning in the region.