Amphibian and reptile communities of upland and riparian sites across Indonesian oil palm, rubber and forest

Abstract

Indonesia is the largest producer of oil palm and the second largest exporter of rubber worldwide; a significant part of the country's rainforests have been converted to agriculture. Conservation measures are needed to assess and reduce the impact of agricultural intensification on the vertebrate fauna, but limited effort has been put so far in understanding the effects of habitat conversion on reptiles and amphibians. Here we study community composition, species richness and abundance of the herpetofauna of the densely farmed Jambi province, central Sumatra (Indonesia). We compared reptile and amphibian communities of upland and riparian sites of lowland rainforest as well as upland and riparian sites of oil palm and rubber plantations through visual-aural encounter surveys and pitfall trappings. Plantations tended to have lower amphibian abundance when compared to riparian forest, but not compared to upland forest. There is a trend for higher amphibian numbers and species in riparian sites of all habitat types. Rare amphibians were much more abundant in riparian forest and common amphibians were more prevalent in plantations, especially oil palm. Surprisingly, reptile richness and abundance was higher in oil palm plantations than all other habitats. Plantations comprise mostly common reptile and amphibian species of low conservation interest, and communities were markedly different between plantations and forests. Several species were recorded for the first time in the sampled region. We conclude that in our region, riparian sites appear to be important for maintaining amphibian populations, but forest is doubtlessly irreplaceable to conserve rare amphibians. Nevertheless, in our study oil palm monocultures harbored a relatively high reptile density and richness.