【摘要】 在亚高山岷江冷杉林中选取≤50m2、50~150m2和>150m2的林窗,每种类型内都包含3种华西箭竹盖度(≤20%、20%~50%和>50%),共调查林窗9个。通过野外群落学调查,研究林窗内岷江冷杉、糙皮桦和川滇长尾槭这3种主要乔木树种幼苗的结构和分布格局。结果表明:1)在华西箭竹盖度大的林窗中,3个树种的各高度级幼苗都不多,林窗形成后,绝大多数林窗被华西箭竹植株定居,竹盖度对主要树种幼苗总密度以及岷江冷杉幼苗密度的影响显著(p<0·05);2)华西箭竹盖度对岷江冷杉幼苗密度的影响最明显,主要是由于3个树种的生态学特性存在差异,岷江冷杉在没有华西箭竹分布或箭竹盖度小的地方优先更新;3)3种幼苗在9个林窗几乎全为聚集分布,这主要取决于幼苗生物学特性及林窗环境。林窗大小和华西箭竹盖度的综合作用对优势树种幼苗的结构和分布格局产生影响。更多还原

【Abstract】 The effects of gap size and coverage of dwarf bamboo, Fargesia nitida, on structure and spatial pattern of the seedlings of Abies faxoniana,Betula utili and Acer caudatum var.prattii in gaps of Abies faxoniana forest were examined in Wolong Giant Panda Nature Reserve, Sichuan Province. The gaps (≤50 m~2,50～150 m~2 and >150 m~2) were selected, there are 3 F. nitida coverage(20%, 20%～50%and >50%) in each gap area type. The results showed: 1) The seedlings of the three dominant species were few in gaps with highest coverage of bamboo. After gap formed, F. nitida inhabited the most gaps, there were significant differences in number of seedlings of all and A. faxoniana among the gaps with different bamboo coverage (p<0.05); 2) The influence of bamboo coverage on seedlings density of A. faxoniana was more obvious than those of B. utilis and A. caudatum var. prattii for the reason of different ecological characters among the three species. A. faxoniana is shade_tolerant species, which firstly regenerated on the area with no or few bamboo existence; 3) The spatial analyses revealed that all seedlings in different gaps were nearly clumped at varied spatial scales, which was caused by not only the biological characters of different tree seedling but also gap environment. We concluded that the combined effect of gap size and bamboo cover would influence the density, structure and spatial pattern of the tree seedlings.更多还原