Quantitative analysis of the community structure of tropical amphibian assemblages and its significance to conservation

Amphibian community structure in five tropical sites was studied using dominance, diversity, evenness indices, niche breadth and overlapping scores and association analysis. Ten species of amphibians with average density/ha varying from 8 to 49 in different sites were collected.Rana limnocharis andBufo melanostictus were respectively the dominant amphibia in paddy fields and other sites. Niche breadth scores indicatedRana limnocharis, Bufo melanostictus andRana cyanophlyctis as habitat generalists indicating wide tolerance to environmental gradients. Five frog speciesi.e. Rana tigerina, Microhyla ornata, Ramanella variegata, Uperedon systoma andPolypedates maculatus were considered habitat specialists indicating narrow tolerance to environmental gradients. Niche breadth scores were found to be a function of the cumulative relative abundance value of different species. The niches ofRana limnocharis andRana cyanophlyctis, Bufo melanostictus andBufo stomaticus showed maximum overlapping.Rana tigerina showed maximum niche overlapping withRana variegata in paddy fields and withMicrohyla ornata when all sites were taken together. The coefficient of community index was maximum between the paddy fields and minimum between the paddy fields and forest site.Rana tigerina occurred very sparsely and analysis of data indicates that its population are threatened and require conservation measure.