We examined the role of subterranean termites in decomposition of cattle dung, various herbaceous plant species and wood in a Chihuahuan desert ecosystem. From July-September, termites removed dung at a rate of 0.63 g day-1 accounting for a percent mass loss of 19.5-100%. During the autumn subterranean termites consumed more than 50% of the leaves of the shrub Larrea tridentata, the grass Erioneuron pulchellum and annual plant Lepidium lasiocarpum and Baileya multiradiata but used very little of two other annuals Eriastrum diffusum and Eriogonum trichopes. Yucca inflorescence stalks on plots with termites lost 23% of their original mass in 30 months while those on termite free soils lost 11%. Elimination of termites resulted in reduction of fluff grass, Erioneuron pulchellum biomass, thereby affecting the structure of the ecosystem.