磨盘山天然次生林凋落物数量及动态研究

Abstract

This study investigated the composition and spatiotemporal dynamics of litterfall at the community scale,on the basis of 144 square traps distributed uniformly in a 5.76 hm2permanent plot located in the deciduous broad-leaved forest of Mopan Mountain. The litterfall samples were collected monthly from April to November in 2006. The results showed that the annual litter production was 3039.6 kg / hm2. The proportion of leaves( 2499.2 kg / hm2) was 82.22%,and that of branches was 9.92%. The combination of flowers,fruits and barks was less than 5%. The leaf litters were from 42 tree species, accounting for 91.30% of the total number( 46) of the tree species in the plot. The main sources of leaf litterfall were Fraxinus rhynchophylla,Juglans mandshurica and Quercus mongolica,accounting for 82.97% of the overall amount. The litterfall exhibited evident spatial heterogeneity,with 200—400g litters in 99 traps and 600g litters in 2 traps. Some traps collected as many as 19 species,but most( 29 traps) did only 12 species. A single-peaked curve described the dynamic of monthly litterfall,and 69. 78% of litterfall occurred in September and October. Leaf litterfall peaked in autumn andexhibited the same temporal trend as the overall litterfall. However,different species peaked in a different manner,with Juglans mandshurica at August and September,Ulmus japonica at September and October,Acer mono at October,and Quercus mongolica at October and November,respectively.