Since significant quantities of plant litter are buried by wind and water in this desert, we designed studies to address the following questions: What are the relative contributions of bacteria, fungi, and microarthropods to litter decomposition? Is there a pattern of microarthropods succession related to the stage of litter decomposition? What are the differences in buried and surface litter decomposition? The initial stages of buried litter decomposition appears to be via bacteria, which are grazed upon by nematodes. Removal of the nematode predator apparently allowed nematodes to overgraze the bacteria, reducing their population size and reducing decomposition. Without predators, grazers appear to be detrimental to decomposition, as has been suggested by Hanlon and Anderson (1979). Thus, in desert ecosystems, microarthropods affect litter decomposition by a heretofore undescribed mode: preying on free-living nematodes.