Effects of termite exclusion on decay of a high-density wood in tropical rain forests of Peninsular Malaysia

The effect of excluding termites on wood decay was evaluated in two tropical lowland rain forests in West Malaysia. Billets from the tree, Paranephelium macrophyllum King (Sapindaceae), were placed in either of two designs of lidless stainless-steel trays on the forest floor. The control trays had openings at the bottom and lower sides while the trays designed to exclude termites had the openings covered with stainless-steel mesh. The loss rates of carbon, nitrogen and phosphorus, and the ratios of carbon/nitrogen and carbon/phosphorus, were compared for wood samples from which termites had or had not been excluded. Comparisons were made at yearly intervals over a period of three years. C, N and P were lost over two or three years. The C/N ratio declined over the experimental period, indicating a slower loss of N compared with C. There was a significant difference in the C/N ratios of the wood samples between the two types of trays for one of the forest sites; the ratio was greater when termites were not excluded, indicating that the termites had enhanced nitrogen release from the decaying wood. The advantage of the present termite exclusion method over other methods is discussed.