间伐强度对红松人工林下草本植物多样性及其组成的影响

Effect of thinning intensities on species diversity of undergrowth herbage of Pinus koraiensis plantation

通过测定和比较红松人工林下光照条件的差异，植被组成及多样性的变化，研究5种不同间伐强度对红松林群落组成的影响。结果表明：随间伐强度增大，林内散射光强度增大，单子叶植物科的数量增多，双子叶植物减少。间伐强度不同，红松林内草本建群种不同。间伐可改变群落的植物多样性、均匀度和丰富度，其中以弱度区最明显。运用关联度分析得出：不同间伐强度红松林下的无截取散射光量对植物多样性各指标影响的大小顺序为丰富度指数〉均匀度指数〉多样性指数〉优势度指数。综合分析认为，合理间伐红松林，使其密度维持在1000～1600株·hm^-2最有利于维护红松林的稳定。

According to the investigation and comparison of illuminance, the composition and the diversity of undergrowth herbage of Pinus koraiensis forced by 5 different thinning intensities, the effects of thinning intensities on the stability of P. koraiensis were studied. The results showed： the dispersion light in undergrowth herbage improved by enhancing the thinning intensity; the species of monocotyledon increased, but the dicotyledon decreased; the composition of the dominant species of the undergrowth herbage varied greatly with the different thinning intensities. Thinning can improve the species diversity, evenness and abundance of communities, especially the weak thinning. The analysis of association study shows that the order of dispersion light intensity influencing diversity index was： abundance 〉 evenness 〉 diversity 〉 ascendency. It can be concluded that reasonable thinning intensity 1 600 - 1 000 trees· hm^- 2 was benefit to the stability of P. Koraiensis plantation.