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通过对沙兰杨密度调整的7年试验表明,合理的初植密度是杨树速生丰产的最佳技术措施之一;密植林虽可通过抚育间伐调整其密度,以提高林分产量,但由于密度效应的影响而不能获得理想效果;初植密度为1 667株/ha的密植林分经间伐后,其蓄积虽比417株/ha的稀植林分多4m~3/ha,但后者的20cm以上径阶的株数是前者的164.5%,檩材出材量是前者的4.37倍,其经济效益差异显著。分析认为,对密植林分抚育间伐的时间要早,强度要大,一次间开。
Seven-year experiments on the density adjustment of Sallaria yunnanensis showed that reasonable initial planting density was one of the best technical measures for poplar fast-growing and high yielding. Although the density of dense-planting forest could be adjusted by raising the density to improve the stand yield, Density effect and can not get the desired effect. The density of the plantation density of 1 667 plants / ha after thinning, although the accumulation of more than 417 plants / ha sparsely-planted 4m ~ 3 / ha, but the latter The number of orders of diameter above 20cm is 164.5% of the former, and the output of lumber is 4.37 times that of the former, and the difference in economic benefits is significant. Analysis shows that the close planting tending thinning of the time earlier, the intensity should be large, open one time.