TWENTY YEARS OF LITTER FALL DYNAMICS IN SUBTROPICAL EVERGREEN BROAD-LEAVED FORESTS AT THE DINGHUSHAN FOREST ECOSYSTEM RESEARCH STATION

Abstract

In this paper, we summarize 20 years of observations and measurements on the production, composition, and seasonal dynamics of litter and leaf litter production of dominant species in the southern subtropical evergreen broad-leaved forests at the Dinghushan Forest Ecosystem Research Station. Annual litter production ranged from 6.39 t·hm -2 to 11.04 t·hm -2 with an average of 8.45 t·hm -2. The variation in the annual litter fall was remarkable. Total litter production decreased over the past 20 years reflecting changes in the compositional characteristics and successional stages of the forest. There were two litter fall peaks each year: one at the beginning of the rainy season (April and May) and the other at the end of the rainy season (August and September). The different components of litter production showed a consistent annual temporal sequence in the following order: leaves; flowers and other mixed-materials; branches. The mean annual leaf litter production of Castanopsis chinensis, Schima superba, Cryptocarya chinensis and Cryptocarya concinna was 1.86, 0.50, 0.26 and 0.40 t·hm -2, respectively, which accounted for about 70% of the total leaf litter production. Leaf litter production of the dominant species greatly influenced the dynamics of total litter production, and, to some degree, the dynamics of litter production reflected changes in the forest biomass and community composition over the past 20 years.