Effects of Initial Litter Accumulation and Climate on Litter Disappearance in a Desert Ecosystem

We examined monthly litter disappearance from initial concentrations of 50g, lOOg, 150g and 200g * m2. Approximately 35%-50% of the litter disappeared each month from May-September. In March and April litterfall input exceeded litter loss. Litter loss was consistently higher in the lOOg * m-2 accumulation than from the other concentrations. Stepwise regression analysis showed that litter loss varied as a function of soil temperature at 15 cm (r2 = 0.40) and that initial litter quantity was the second most important variable (increased r2 to 0.45). Monthly litter disappearance was apparently independent of monthly rainfall. Abiotic variables gave an r2 of 0.48, suggesting that much of the seasonal variation in litter disappearance is attributable to the soil biota. Suppression of microarthropods by treating the soil with chlordane insecticide resulted in marked reduction in litter disappearance.