论文部分内容阅读
分别对黄龙山林区近自然经营间伐强度为15%(弱度间伐)、30%(中度间伐)和45%(强度间伐)的油松人工林进行样地调查,以未间伐林为对照,研究间伐7年后油松人工林幼苗更新、林分生长、物种多样性和土壤特性等指标的变化,评价间伐抚育的效果.结果表明:随着间伐强度的增加,1～7年生油松幼苗的数量和各项生长指标均增加,而生长指标的年均增长率表现出先增大后减小的趋势,且以中度间伐最大;与对照相比,弱度、中度和强度间伐使油松单株材积分别提高了20.9%、32.1%和52.6%,单位面积蓄积量分别减少了4.4%、15.1%和25.3%,但蓄积量的年均增长率却增加了28.6%、46.2%和82.0%;间伐样地内的物种多样性和土壤特性得到改善,表现为强度间伐>中度间伐>弱度间伐>未间伐.本试验条件下,间伐强度45%更适宜黄土高原地区油松人工林的抚育管理.
The sampling plots of Pinus tabulaeformis plantation near natural management in Huanglongshan forest area were 15% (thinning), 30% (moderate thinning) and 45% (intensive thinning) respectively. The effects of thinning and tending on the growth of seedlings of Pinus tabulaeformis plantation in seven years after the thinning were studied.The results showed that with the increase of thinning intensity, The number and the growth index increased, while the annual growth rate of the growth index showed the trend of first increasing and then decreasing, and the middle thinning the largest; compared with the control, the weak, moderate and intensive thinning oil The single volume of Pinus massoniana increased by 20.9%, 32.1% and 52.6%, respectively, and the volume per unit area decreased by 4.4%, 15.1% and 25.3% respectively, but the average annual growth rate of the accumulation increased by 28.6%, 46.2% and 82.0% %. The species diversity and soil characteristics of thinning plots were improved, which showed that the thinning intensity> middle thinning> thinning thinning> non-thinning.In this experiment, the thinning strength of 45% is more suitable for the Pinus tabulaeformis plantation in the Loess Plateau Tending management.