Litter Dynamics of Three Subalpine Forests in Western Sichuan

Litter production, components and dynamics were investigated and forest floor litter was quantified throughout a whole year in three subalpine forests, dominated by tree species of spruce (SF), fir (FF) and birch (BF), in Western Sichuan, China, in order to understand the key factors that influenced litter production and dynamics. Litterfall in the three forests consisted mainly of leaves, woody litter, reproductive organs and moss. Contribution of leaf litter to the total litterfall was significantly (P < 0.05) greater than that of woody litter, reproductive organs or moss. Regardless of the stands, litterfall exhibited a marked monthly variation with the maximum litterfall peaks occurring in October, with smaller peaks occurring in February for SF and FF, and May for BF. The analysis indicated that tree species, stand density, leaf area index (LAI), stand basal area and stand age were the key factors determining litter production. Meanwhile tree species and phenology controlled the litter dynamics, with wind and snow modifying the litter components and dynamics.