人为干扰(间伐)对红松人工林林下植物多样性的影响

The effects of anthropogenic disturbances (thinning) on plant species diversity of Pinus koreansis plantations

根据对辽宁东部地区红松人工林林下高等维管植物调查资料，采用Simpson指数（SP），Shannon-Wiener指数（SW）和Pielou均匀度指数（PI）等进行α多样性测度分析，探讨人为干扰（不同间伐强度）对红松人工林下植物多样性的影响。结果表明：人为干扰改变林下光照环境，促进植物生长，对红松人工林下高等维管植物的物种多样性产生较大影响。随着干扰（间伐）强度增加，红松人工林下植物种类、数量明显增加；不同干扰强度区林下植物种类高于对照区200％～400％；不同干扰强度红松人工林下植物种类的丰富度和多样性明显高于对照区；人为经营干扰改变了红松人工林下植物组成，随干扰强度增加．共有物种增加．且人为干扰林分的共有种和相似系数明显高于对照区。

In this paper, we studied the influence of anthropogenic disturbances （thinning management） on the species diversity of understory plants in Pinus koreansis plantations in eastern Liaoning province. Investigations were conducted by establishing sample-plot in the experimental sites （20 m × 30 m）. Production of trees was estimated by measuring tree height, DBH and canopy width in the experimental sites under different thinning intensities. Diversity of understory vegetation was surveyed by sample plots method in Spring （the middle ten-day in May） and Summer （the last ten-day in July）. Two sample plots （1m × 10m） were established in each experimental site along the hillside for surveying the plant species, height, abundance and coverage. Based on the calculations of a-diversity such as Simpson index （ SP）, Shannon-Wiener index （SW） and Pielou index （ PI）, we analyzed the species diversity of understory plants in Pinus koreanis plantations. The results showed that anthropogenic disturbances had altered the understory light conditions, improved the growth of vegetation, and impacted obviously the species diversity of higher vascular plants. The more the disturbance density enhanced, the more plant species and quantity increased. There were 2 4 times species in all of the thinned plantations mote than those of in the control plantations. The richness and diversity of plant species were significantly higher in Pinus koreansis plantations with different disturbances than those in the control plantations. Anthropogenic disturbances changed the composition of understory plants, and the mutual plant species increased with the disturbance intensity enhanced. In addition, both the mutual plant species and analogical coefficient in disturbance plots were higher than those of the control plots. Overall, the results suggested that anthropogenic disturbances not only improved the biodiversity of understory plants, but kept on the forest ecological benefits （e. g., water conservation）, and possibly promoted positive succession of Pinus koreansis forests as well.