MOUND-BUILDING TERMITES AND SOIL MICROBIAL BIOMASS - AN INTERACTION INFLUENCING TERMITE ABUNDANCE

Termites are more abundant in the warmer lower latitudinal regions of the earth. Within these broad geographic regions, however, the precise nature of the factors influencing termite abundance is poorly underst ood. In this paper I have examined the abundance of detritivorous, mou nd-building termites and certain aspects of the climate, soils and veg etation at 14 sites in tropical northeastern Australia. No relationshi p between termite mound density and the particle-size characteristics of surface soil horizons, plant available phosphorous or rainfall was found. Microbial biomass carbon level of the surface soil was found to have a strong negative relationship with termite mound numbers. The n egative interaction between the soil microbial population and termites may be due to the limiting effect of the organic matter processing ca pacity of the soil microbial population on the success of termites in occupying the decomposer niche in any particular area. Microbial bioma ss may therefore be a major factor influencing termite abundance in tr opical Australian landscapes and elsewhere.