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2009—2011年,在广西大明山常绿阔叶林一个典型坡面的上坡、中坡和下坡分别建立24个20 m×20 m的固定样地,测定不同林冠层次(上层、中层和下层冠高分别为:>8、4~8和0~4 m)的覆盖度并监测林下植物的更新,研究林冠垂直结构的动态变化及其对林下植物更新的影响.结果表明:随着2008年特大冰冻灾害后森林的恢复,林冠总覆盖度显著增加,从2009年的54.0%提高到2011年的67.4%,不同冠层覆盖度和恢复增长存在显著差异,上层林冠覆盖度显著高于中、下层,而中、下层林冠的恢复增长显著优于上层林冠.林下更新的木本植物共55种,优势科和优势种与现有群落的基本一致.同一年份不同坡位林下更新植物的物种多样性指数差异不显著,但同一坡位不同年份间存在显著差异.不同冠层的覆盖度与更新植物的物种丰富度和多度相关性不显著;中层、下层和林冠总覆盖度与林下更新植物的Shannon指数、Simpson指数和Pielou均匀度指数呈显著负相关,表明冠层覆盖度显著影响着林下更新,中、下层林冠对林下更新植物多样性的作用更明显.
From 2009 to 2011, twenty-four 20 m × 20 m fixed plots were established on the uphill, mid-slope and downhill of a typical slope in the evergreen broad-leaved forest in Daming Mountain, Guangxi. The coverage of the lower crown were> 8, 4 ~ 8 and 0 ~ 4 m, and the plant undergrowth was monitored to study the dynamic changes of canopy vertical structure and its effect on plant regeneration.The results showed that With the restoration of forests after the 2008 super-freezing disaster, the total canopy cover increased significantly from 54.0% in 2009 to 67.4% in 2011, with significant differences in canopy coverage and restoration growth, and significantly higher canopy cover at the upper levels In the middle and lower layers, the middle and lower canopy restoration was significantly better than that of the upper canopy.Among 55 new species of woody plants, the dominant families and dominant species were basically the same as those of the existing community. There was no significant difference in the index of species diversity of the updated plants, but there were significant differences in different years of the same slope.The correlation between the coverage of different canopy and species richness and abundance of the regenerated plants was insignificant. The total coverage of middle, lower and canopy Degree and undergrowth of the plant Shannon index, Simpson index and Pielou evenness index showed a significant negative correlation, indicating that canopy cover significantly affected the regeneration of the forest, the middle and lower canopy regeneration plant diversity more obvious role.