Structure and composition of amphibian communities in human modified landscape at Gianyar regency, Bali

Abstract

Landscape modification has affected amphibian communities which then accommodate specialist or generalist species. This research aimed to observe the response of amphibian communities along a gradient habitat of human modified landscapes (settlements, rice fields, farmland/cropland, and monoculture stands) in Gianyar Regency, Bali. Observations were carried out in July-October 2014 using the standard Visual Encountered Survey method. In addition, the body condition of generalist species were also assessed. Eleven amphibian species (n=751 individuals) consisting of 5 families were found. Amphibian species were dominated by Duttaphrynus melanostictus (31.8%), Microhylla palmipes (21.84%), and Fejervarya limnocharis (17.84%). The amphibian community could be found in three separate habitats i.e. settlements-farmland/cropland, monoculture stands, and rice fields. Non-aquatic species in monoculture stands have the highest diversity (Shannon-Wiener index H’ 1.12), with lowest found in residential areas (H’ 0.31). The diversity of amphibian tend to increases when (1) close to water sources, (2) vegetation cover increased, and (3) anthropogenic disturbance factor decreased. Occidozyga lima was a specialist, as it was only found in specific habitat type (rice fields), whereas D. melanostictus was a generalist as it was found in all habitat types with high encountered rates. Further observations on the body condition of the generalist (D. melanostictus) showed that landscape modification in human modified landscape tend to increase abundance of the species but decrease its body size.