Termite ecology in a dry evergreen forest in Thailand in terms of stable (δ13C and δ15N) and radio (14C, 137Cs and 210Pb) isotopes

Abstract

Stable (δ13C and δ15N) and radio‐ (14C, 137Cs and 210Pb) isotopes were determined for termites that have been sampled from a dry evergreen forest in Thailand. A wood‐feeding termite, Microcerotermes crassus, was separated from soil‐feeders: Termes propinquus, Termes comis and Dicuspiditermes makhamensis by δ13C and δ15N values. The Termes group in Thailand had less diverse values in δ13C and δ15N than those in Australia, where the feeding habits of the ‘Termes’ group are more diverse. Other soil‐feeding termites produced similar δ13C values, but a larger range in δ15N values. 14C‐percent modern carbon (pMC) values suggest that the soil‐feeding termites used younger carbon than the wood‐feeding termites, and this was consistent with the termites from Cameroon, central Africa. Values of δ13C and 14C‐pMC indicate that surface soil was used by a soil‐feeding termite, D. makhamensis, in making the nest mounds, and deeper soil (10–30 cm) by a fungus‐growing termite, Macrotermes carbonarius. 210Pb and 137Cs were scarcely incorporated into the termites, although 214Pb was recovered from the workers. The results suggest that stable‐ and radioisotopes are useful in the study of detritivorous animals, organic matter decomposition and ecosystem engineering.