A comparison of surface and buried Larrea tridentata leaf litter decomposition in North American hot deserts.

Mass losses from surface Larrea tridentata leaf litter bags ranked highest to lowest: Chihuahuan Desert, Sonoran Desert, Mojave Desert, Coloradan Desert. Mass losses from buried litter bags were essentially equal, c40%, in each of the deserts for bags buried from March-October. There was low correlation between rainfall and mass loss of buried litter and surface litter. Mass losses from insecticide-treated buried bags were lower than from untreated bags. There was a greater abundance of nematodes in insecticide-treated bags than in untreated bags. Tarsonemid mites were found only in litter bags from the Chihuahuan desert. The most abundant microarthropods in buried leaf litter in the other deserts were predatory raphignathids, tydeids and arctacarids. Decomposition (litter disappearance) was highly correlated with long-term rainfall patterns, which have presumably served as the selective agents for the soil biota active in the decomposition process. Thus, litter disappearance does not respond to annual fluctuations in rainfall amounts.-from Authors