【摘要】 对18年生落叶松人工纯林采用不同大小的林隙间伐,辅以不同的整地措施进行近自然化改造,同时以相同强度的常规均匀间伐处理为对照,分析改造后第1年和第2年林下植物多样性的变化。结果表明:与对照相比,改造后第1年和第2年林下草本植物种数、密度、盖度、平均高和多样性指数(Simpson指数、Shannon-Wiener指数和Pielou均匀度指数)均有较大幅度增加,改造后第2年差异达到显著水平(均匀度指数除外)(P<0.05);近自然化改造林下草本植物优势种中喜湿植物明显增加;无论是改造后第1年还是改造后第2年,不同大小林隙处理间林下草本植物种数、密度、盖度、平均高和多样性指数均无显著差异(P>0.05);改造后第1年,经整地的大林隙、中林隙和小林隙林下草本植物密度、盖度和平均高均显著高于不整地(P<0.05),第2年,整地措施对草本植物的影响效果下降;与对照相比,改造后第1年和第2年林下木本植物种数、密度、盖度、平均高和多样性指数均未发现显著差异(P>0.05)。近自然化改造有利于林下草本植物的发育和草本植物多样性的提高,但对林下木本植物的影响还有待深入研究。更多还原

【Abstract】 Changes in the understory plant species diversity in Larix gmelinii pure plantations were investigated after carrying on a close-to-nature stand transformation with different gap sizes and various soil disturbances,with conventional uniform thinning as the control.Increases in species number,quantity,coverage,mean height and diversity indexes (Simpson’s diversity index,Shannon-Wiener index,Pielou’s evenness index) of herbaceous species were detected in the transformed stands in the 1st and 2nd year;and significant differences (P < 0.05) were detected for all the indices except for evenness index in the 2nd year.Among the dominant herbaceous species,hygrophilous ones increased dramatically in the gaps of the transformed stands.No significant differences were found in species number,quantity,coverage,mean height and diversity index of herbaceous species with different gap size.In the 1st year after transformation supplemented with scratching the floor,the herbaceous species had significantly greater quantity,coverage and mean height in comparison to that without scratching the floor;but the differences diminished in the 2nd year.No significant differences in species number,quantity,coverage,mean height and diversity indexes of woody species were detected between the close- to-nature transformation and the ordinary uniform thinning.Our results suggest that the close-to-nature transformation favors the development of understory herbs,and promotes the diversity.However,more work should be done to determine the influence of the transformation and soil disturbances on the development of woody species.更多还原