梵净山冷杉林与珙桐凋落物现存量动态特征 The Dynamics of Litter Accumulation of Fir and Davidia involucrate in Fanjing Mountain

对梵净山冷杉和珙桐分别设置样地，研究该地区该群落类凋落物的年产量、月动态变化以及组成特征。结果表明：梵净山冷杉林与珙桐林年凋落量分别为5.68 t∙hm−2和4.67 t∙hm−2，梵净山冷杉凋落量月动态变化为双峰形，珙桐的月落量在12月~到8月份起伏不大，在秋季达到最大凋落量；净山冷杉林的凋落物组成比较丰富，2种森林群落落叶和落枝占有较大比重，群落内部和外部环境的变化都会对凋落物组成和产量产生影响，胸径、立木密度、郁闭度对凋落物产量和组分有显著影响。 Soil about fir and Davidia involucrate was sampled to research annual output, monthly dynamics, and composition of litter in Fanjing Mountain. The result showed that the annual litter of fir and Davidia involucrate was 5.68 t∙hm−2 and 4.67 t∙hm−2 respectively. The monthly dynamics of litter of fir took on double peak. The monthly litter of Davidia involucrate had little change from December to August in the following year, and reached its maximum amount in the fall. The composition of fir forest was rather abundance. There was a large proportion of defoliation and cladoptosis in these two kinds of forest community. The change of community and environment would influence the composition and output of litter. Diameter at breast height (DBH), stem density and canopy density had a great influence on output of litter.