为探讨台风干扰对亚热带常绿阔叶林凋落物总量、组成和时间动态变化的影响,对浙江天童山2种常绿阔叶林类型——栲树(Castanopsis知rgesii)群落和木荷(Schimasuperb)群落的凋落物进行了为期5年(2008-2012)的观测研究.结果显示:天童栲树林和木荷林的年平均凋落物量分别为6.465t·hm-2和6.947t·hm-2台风影响年的年凋落量和台风季节月均凋落量均高于无台风影响年.两种群落类型的总凋落物组成比例皆为叶〉枝〉碎屑〉花〉果〉树皮,其中叶比例约占70%,枝比例约占17%;台风影响年与无台风影响年相比,叶比例有所下降,枝条比例明显上升.台风影响年与无台风影响年的凋落量时间动态不同,无台风影响年两种群落类型的凋落高峰发生在春季(4—5月)和秋末(10—11月),均为双峰型;台风影响年凋落模式为三峰型,凋落高峰发生在春季、台风季和秋季.两种群落的叶凋落时间动态在不同台风影响年份有所区别,在台风干扰较弱的年份(2008、2009和2011年)栲树林叶凋落动态为双峰型、木荷林为三峰型;在台风干扰强度较大的年份(2012年),两种群落类型的叶凋落动态均为三峰型,这说明台风干扰能改变亚热带常绿阔叶林的时间动态,且台风强度对不同森林群落的干扰程度存在差异.
To understand the effects of typhoon disturbance on the production, composition, temporal dynamics of litter in subtropical evergreen broad-leaved forest, a 5-year study from January 2008 to December 2012 on two types of evergreen forests, C. fargesii community and S. superba community, in Tiantong, Zhejiang, was carried out. Average annual litterfall are 6. 465 t · hm-2 and 6. 947 t · hm-2 in C. fargesii community and S. superba community,respectively. Annual litter production and monthly litterfall in typhoon season were both signifi- cantly higher in typhoon years than that in normal years. Orders of proportions of different sorts litterfall in the two types of communities are leaves 〉 twigs 〉detritus 〉flowers 〉barks. The total leaves production accounted for about 70~ of total litter. Proportion of twigs reached about 17 ~. Proportion of leaves declined from typhoon years to normal years, while the proportion of twigs had an opposite trend. The dynamics of monthly litter production in both communities fol- lowed a bimodal distribution (with peaks in April-May and October-November) in normal years, and trimodal distribution (with an extra peak in typhoon season. ) in typhoon years. The dynam ic of monthly leaves production was different between the two types of communities in different typhoon years. It had two peaks in C. fargesii community and had three peaks in S. superba community in the years (2008, 2009 and 2011 ) with weak typhoon disturbance. However, it showed three peaks in both communities in the year (2012) with strong typhoon disturbance. These results suggested that typhoon disturbance can change the dynamics of litterfall in sub- tropical evergreen forest, and these impactions may various in different types of communities un- der different strengths of typhoon.