Species diversity and community structure of amphibians of selected agroecosystems in Thrissur, Kerala

Abstract

The research work entitled “Species diversity and community structure of amphibians of selected agroecosystems in Thrissur, Kerala” was carried out in the agroecosystems such as Cashew Plantation, Coconut Plantation, Homegarden, Rubber Plantation, Wetlands and in Botanical Garden from January 2017 to May 2017. The main objective of the study was to find out the species diversity and community structure of amphibians of selected agroecosystems and its association with various habitat parameters. A total effort of 225 man hours were spent in the field during night. The methods adopted for the study include Quadrat Sampling, Visual Encounter Survey along with the Opportunistic Sampling. A total of 14 anurans were recorded from the study locations. Species richness was found to be highest in Rubber plantation with eight species. Encounter of amphibians was more in Wetlands followed by Rubber Plantation. All the sampling units in Homegarden and Wetlands (25 quadrats each) had the presence of amphibians. The research found significant difference in amphibian diversity among the different agroecosystems. Visual encounter survey combined with opportunistic sampling was found to be an efficient methodology to assess the amphibian species richness of an agroecosystem. The study found an inverse relation between the presence of amphibians and reptiles in the sampling units. The microhabitat variables such as soil moisture, soil pH, litter depth, maximum air temperature, and minimum air temperature has a positive influence on the presence of Pseudophilautus wynaadensis while shrub density, soil temperature at 5 cm depth and evaporation had significant inverse relation. The present work recorded two Western Ghats endemic species Indosylvirana sreeni and Pseudophilautus wynaadensis, from the agroecosystems of Thrissur while the latter was a threatened one with Endangered status as per IUCN Red List. Both the reports of Pseudophilautus wynaadensis and Indosylvirana sreeni are of interest, as they are reported from a lower altitude (50m) than the already known lowest altitude range (900m and 100m respectively) of these species. Thus, the study highlights the importance of the agroecosystems in acting as important habitats for the amphibian fauna in Kerala.