长白山区次生阔叶林采伐林隙更新研究

Study on Logging Gaps Regeneration in Secondary Broad-leaved Forest in Changbai Mountain

从林隙大小和林隙年龄两个方面研究了以椴树、色木槭和蒙古栎为主的次生阔叶林经营采伐形成的林隙及其更新特征。结果表明:冠林隙面积<20 m2的林隙占42.8%,20～40 m2的林隙占23.8%,40～60 m2的林隙占33.4%。38.1%的林隙呈圆形,61.9%的林隙呈椭圆形,其中38.5%为南-北方向,46.2%为东-西方向,15.3%为东北-西南方向。林隙一般由3～4株采伐木形成,采伐木主要由椴树、蒙古栎和山槐组成。非林隙林分更新中灌木占优势,林隙更新中乔木占优势,且随林隙面积和形成年龄增加而增强。林隙内的树种多样性和更新密度明显高于非林隙林分。综合多样性随林隙面积和年龄的增加而下降。不同大小级林隙内的优势种不同,以阳性树种占大多数。

The regeneration trait of logging gaps in relation to sizes and ages in secondary broad-leaved forest which was predominated by Tilia amurensis, Acer mono and Quercus mongolica in Changbai Mountain was studied. The research result showed that there were 42.8% （canopy gaps area 〈 20 m^2） ,23.8% （20 - 40 m^2）, 33.4% （40 - 60 m^2） in the proportion of gap size. 38.1% of gaps shape were rotundity and 61.9% were oval. 38.5% of the oval gaps lay in N-S direction, 46.2% in W-E direction and 15.3% in N-E to S-W direction. These gaps were usually formed after 3 - 4 trees logged which were mainly composed of Tilia amurensis, Quercus mongolica and Maackia amurensis. The regeneration layer was dominated by the shrub in non-gap stands but arbor in the gaps. Moreover, the dominance would rise with increasing sizes and ages of gaps. The species diversity and density were obviously more in gaps than in non-gap stands. The synthesis diversity had a tendency to decline with increasing sizes and ages of gaps. The dominance species were different in gaps of different sizes, but were mainly composed of intolerant species.