SUBTERRANEAN TERMITE FAUNA ON A PEATLAND: A PRELIMINARY ASSESSMENT OF THE SPECIES DIVERSITY AND BIOMASS UNDER DIFFERENT LAND USE TYPES

Abstract

Owing to their wet nature, peatlands in their original conditions may not be favorable habitats for most ground-dwelling organisms. Apart from being acidic, peat is water saturated most of the times, making it unlikely habitatble for such organisms. After the construction of drainage system, however, substantial amount of water can be drawn out from the peat, resulting the drop of water table. We hypothesized that the alteration of this fundamental feature of peatlands might promote the proliferation ground-dwelling organisms in peatland habitats and/or colonization by non-native ones. We tested our hypothesis by surveying termite species richness and biomass under different land use systems that reflected a gradient of water table alteration (from shallower than 20 cm to deeper than 100 cm below the surface). The study has been carried out under peat swamp forest, rubber jungle, rubber plantation, oil palm plantation, homegarden, and acacia plantation forest in Bukit Batu area, Riau, Sumatra. We encountered a total 18 spp of subterranean termites with the average of only 6.2 spp found under each land use type. The average subterranean termite biomass was 0.29 gr/m2. Our data did not support our hypothesis in a way that subterranean termites were even most diverse (9 spp) and demonstrated largest biomass (0.53 gr/m2) under peat swamp forest, where the water table was never deeper than 20 cm and the peat was almost always watersaturated. However, the striking differences in species composition between peat swamp forest assemblage and those under other land use types suggest that the conversion of peatland might have significantly reduced the number of species native to this ecosystem, while inviting nonnative ones