LITTER DECOMPOSITION IN A CHIHUAHUAN DESERT PLAYA

Mass loss rates were compared for several types of litter in a flooded desert ephemeral playa. Most nonwoody types of organic matter, including black grama grass, creosotebush leaves and rabbit feces decomposed rapidly. Creosotebush twigs and wood decomposed slowly. About 25% of thc mass was lost due to abiotic leaching. Predater exclusion significantly increased decomposition of creosotebush leaves, but reduced mass loss rate of creosotebush twigs and black grama grass. Decomposition rates were within the range of those found in lakes, and much lower than rates typical of streams. Our data suggest that organisms have little effect on mass loss of debris transported into a desert playa.