中文摘要：

为探索适宜间伐强度的抚育措施,在川中丘陵区高密度的柏木人工纯林中,选择抚育间伐形成的不同柏木密度样地36个,采用样方法,调查光热环境、植物生长和多样性随间伐强度的变化规律。结果表明：间伐后,林内光合有效辐射和气温显著（P〈0.05,下同）升高,空气湿度和土壤相对含水量显著降低,间伐强度越大变化幅度越大。间伐后,林下更新层乔木胸径、冠幅和郁闭度,灌木层盖度和高度,草本层盖度,枯落物层厚度较非间伐样地均显著增加,且随间伐强度增加增值越大;更新层乔木高度在各间伐和对照样地之间差异不显著;间伐显著提高了单株柏木材积,但单位面积内柏木蓄积量显著降低。间伐后,林内植物种数、属数和科数增多,乔木、灌木和草本种数增加;间伐林内植物物种丰富度和多样性Shannon-Wiener指数显著提高,均匀度Pielou指数和优势度Simpson指数变化不明显。间伐和非间伐样地之间共有种为4~9种,相似系数介于16.67%~50.00%。抚育间伐改变了林内光热环境,促进了林下植物的生长更新,丰富了林内植物多样性,强度间伐影响效果更为明显。

英文摘要：

In order to explore appropriate thinning intensity,choosing 36 thinning plots with different cypress density from the pure cypress plantation with high-density in the hilly region of central Sichuan. The variation of ecological factors,plant growth and diversity in different thinning intensity was investigated by sampling method. The results showed that PAR and air temperature were significantly（ P 0. 05 the same below） elevated,while air humidity and soil moisture evidently decreased in the forest after thinning,the change was more obvious when thinning intensity is greater. After thinning,the DBH,crown width and shade density of arbor in the renewal layers were significantly increased. The height and coverage of shrub,litter layer thickness were significantly increased after thinning. The increase value was bigger when thinning intensity is greater. The height of arbor in the renewal layers had no significant difference between the plots. Volume per cypress was significantly increased while cypress volume in unit area was significantly decreased after thinning. The quantity of species,genus and families has elevated after thinning as well as trees,shrubs and herbaceous. Species richness and Shannon- Wiener index significantly increased while the Evenness Pielou index and Domination degree Simpson index had no significant change. Between thinning and non-thinning plot,the common species and similarity coefficient were 4 - 9 and 16. 67% -50. 00% respectively. Thinning changed the thermal environment,promoted the growth of understory plants and enriched the plant diversity. Meanwhile,effect of thinning intensity is more obvious.