Understanding the processes that influence spatial patterns in species richness and composition is central to ecology. A wide range of mechanisms have been proposed but the struggle to find a universal explanation for these patterns continues. The wet evergreen forests of the Western Ghats provide an ideal setting to test the drivers of large scale variation in species richness. We collected primary data comprising 20,400 occurrences of 450 species of woody plants, and built a biome-wide species database, to examine patterns of richness and composition along the entire latitudinal extent of the Western Ghats. This study uses a macroecological approach with a focus on species geographic range to uncover the mechanisms that shape the diversity and distribution of woody plants in the Western Ghats. We then use spatial, edaphic, topographic and climatic variables to test the relative importance of niche based and dispersal based processes in structuring spatial variation in species composition. Finally, using the primary data collected on species occurrence and range size, we establish for the first time, baseline data on the status and distribution of woody plants and, following the IUCN criteria, carry out
species assessments for 250 species of endemic woody plants of the Western
Ghats.