辽西油松人工林不同宽度带状混交改造后混交带内植物多样性的短期变化

摘要

为了确定辽西油松人工林带状混交改造适宜的混交宽度并进一步为油松人工林的可持续经营提供理论参考,采用样方法对辽西地区(朝阳建平)41a生油松人工林5 m、10m、15 m、20 m、25 m、30 m带状混交改造4 a后混交带内灌木及草本植物的种类、平均高、平均盖度、多样性指数变化情况进行对比研究.结果表明:阴坡、半阳坡混交带内植物种类数量分别比对照油松保留带提高130.0％、83.3％,主要以草本植物种类增加为主,阴坡、半阳坡草本植物种类分别平均增加12种、8种,而阴坡灌木种类只平均增加了1种,半阳坡灌木种类更是没有明显变化;混交带内灌木、草本植物高度分别较对照平均提高31.0％、40.4％,盖度分别平均提高184.5％、107.5％,阴坡灌木的平均盖度和半阳坡草本的平均高度均碍到了极大提高,混交带内灌木、草本的平均高和平均盖度均随混交宽度的增加而增大,混交宽度超过25 m,灌木、草本的平均高和平均盖度无显著增长;阴坡5 m混交带、半阳坡6种宽度混交带灌木的各项多样性指数均为0,阴坡25 m混交带的灌木多样性指数最高,除半阳坡均匀度指数外,无论是阴坡还是半阳坡,30 m混交带的草本多样性指数均最大.%In order to determine the best mixed belt width of transformation and to further provide theoretical reference for the sustainable development of Pinus tabulaeformis plantation,41-year-old Pinus tabulaeformis plantations in western Liaoning (Chaoyang Jianping) were belt-mixing transformed with different widths (5 m,10 m,15 m,20 m,25 m,30 m),and the shrub and herb varieties,average height,average coverage and diversity indexes in mixed belts after 4 years of transformation were researched and compared in this study.The results showed:compared with the pine reserve belt,the plant species numbers in mixed belts in shady slope and semi sunny slope increased 130.0 ％ and 88.3 ％,respectively,and were mainly dominated by herb species.The herb species numbers in mixed belts in shady slope increased 12,and that increased 8 in semi sunny slope.However,shrub species numbers in mixed belts in shady slope only increased 1 and in semi sunny slope that even didin't change.The shrub and herb heights in mixed belts increased 31.0 ％ and 40.4 ％,and their coverages increased 184.5 ％ and 107.5 ％,respectively.The average heights and coverages of shrubs and herbs increased with the increase of mixed belt widths,but there was no significant effect when the mixed belt width was larger than 25 meters.The shrub diversity indexes in 5 meters mixed belt in shady slope and all mixed belts in semi sunny slope were all 0,but it reached the maximum in the 25 meters mixed belt in shady slope.Except the evenness indexes in semi sunny slope,in both shady slope and semi sunny slope,the indexes of herb diversity all reached the maximum.