Patterns of butterfly, bird and tree diversity in the Western Ghats

We censused butterfly assemblages of the Western Ghats of India in 15 localities and 8 vegetation types during 67 transects, each 600 m long, and traversed in one hour. The natural vegetation types had relatively high diversities compared to human impacted vegetation types such as scrub/savanna and grasslands. The home gardens and paddy fields had very distinctive species composition, coupled with very low levels of beta diversity. Their constituent species were more widespread. Comparison of these patterns with those found amongst trees and birds reported in similar studies threw up interesting parallels as well as contrasts. Species dissimilarity in evergreen vegetation types was high for trees and butterflies, but low for birds. Bird and butterfly assemblages in monoculture tree plantations had low species richness, less distinctiveness and high levels of dissimilarity, being comprised of rather widespread species. However, on the whole there was little relation between taxonomic groups and vegetation types across diversity parameters. There could be important implications of these patterns of diversity dispersion and their co-variation across taxonomic groups for assigning conservation priorities. We emphasize the need for classifying the landscape, both natural and manmade, on the basis of structural vegetation types, followed by stratified sampling of multiple groups of organisms for monitoring the status of and designing conservation strategy for biodiversity.