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采用样线法调查研究区内林隙分布,共获得36个林隙,大小不同林隙内植物种类组成表现出一定差异,大林隙(300~400m2)乔木树种18种,灌木、草本植物28种;小林隙(<100m2)乔木树种13种,中林隙(100~200m2)11种,两者灌木及草本植物均21种。大、中林隙内乔木树种以江南桤木居多,小林隙中暖木和甜槠占优势;3个林隙中灌木均以青栲幼苗占绝对优势,表明青栲将有可能进入林冠层而逐渐成为优势树种。林隙内乔木树种种数、丰富度指数均大于非林隙,均匀度小于非林隙;灌木、草本植物具有同样规律。乔木树种物种多样性以大林隙最高、中林隙最低;不同面积林隙SW多样性指数、均匀度指数依次为:大林隙>中林隙>小林隙;生态优势度为:中林隙>大林隙>小林隙。灌木、草本植物物种数、丰富度指数表现出300~400m2面积的大林隙内达最大值,并随林隙面积的减小而减小,灌、草层植物多样性最大值也出现在大林隙中;生态优势度指数中林隙最大,小林隙最小。
A total of 36 forest gaps were obtained by using the sample-line method to study the distribution of forest gaps in the study area. The species composition of the gaps was different in different sizes of gaps. There were 18 species of arbor species with large gaps (300 ~ 400m2), 28 species of shrubs and herbs There were 13 species of tree species in the small gap (<100m2) and 11 species of medium gap (100-200m2), both of which had 21 species of shrubs and herbs. Among the large and middle groves, the arbor species mostly came from southern Alnus crest and the warm wood and sweet cloble dominated the small gap; the shrubs in the gap were dominated by the young barley seedlings, which indicated that the barley would probably enter the canopy Gradually become the dominant tree species. The species number and abundance index of tree species in the gaps were all larger than those in non-gaps and the evenness was less than that in non-gaps. The shrubs and herbs had the same pattern. The species diversity of tree species was the highest in the gaps with the largest gaps and the lowest in the gaps. The SW diversity index and evenness index of the gaps in the gaps were as follows: large gap> middle gap> small gap; ecological dominance: middle gap> Gaps> Small gaps. The species diversity and richness index of shrubs and herbaceous plants showed the maximum value within the range of 300-400m2 and decreased with the decrease of the gap area. The maximum value of plant diversity also appeared in the gaps In the ecological dominance index, the gap was the largest and the smallest was the small gap.