不同立地及间伐强度对杉木人工林生长的影响

为探明不同立地及间伐强度对杉木人工林生长影响，在浙江庆元林场3个林区分别开展了不同间伐强度(10%～15%、16%～30%、31%～40%)对杉木（隆宫林区杉木19年生，卢峰和白领头两个林区20年生）人工林生长影响的研究。结果表明：间伐3 a后，隆宫和卢峰林区胸径、单株材积都随间伐强度加大而增加，3个林区16%～30%和31%～40%间伐强度胸径平均连年生长量、单株材积平均连年生长量都要显著高于10%～15%间伐强度，而16%～30%和31%～40%间伐强度之间差异不显著，相同林区不同间伐强度的树高平均连年生长量差异都不显著，3个林区31%～40%间伐强度的平均林分蓄积都较小，隆宫和白领头林区不同间伐强度的林分蓄积平均连年生长量之间都存在显著差异，卢峰林区16%～30%和31%～40%间伐强度林分蓄积平均连年生长量之间差异不显著，但都显著高于10%～15%间伐强度。本研究通过综合林分因子分析得出隆宫和白领头林区的最佳间伐强度16%～30%，而卢峰林区的最佳间伐强度为31%～40%。

Effects of different site and intermediate cutting intensities on growth of planted young Cunninghamia lanceolata forests

In order to verify the effects of different sites and thinning intensities on the growth of the Cunninghamia lanceolata plantations, study was conducted on effect of the thinning intensities (10% to15%、16% to 30%、31% to 40%) of the forest in Qingyuan Forest Farm, Zhejiang Province. The result showed that DBH, single tree volume increased with increasing thinning intensities on Longgong and Lufeng forest area after thinning intensities three years, DBH mean current annual increment, mean single tree volume increment of 16% to 30% and 31% to 40% thinning intensities was significantly higher than the 10% to 15% thinning intensity on three forest, but 16% to 30% and 31% to 40% thinning intensity was not significant, height mean current annual increment of different thinning intensities was not significant on the same forest, mean stand volume of 31% to 40% thinning intensity were lower on the forest zone, mean stand volume current annual in crement of different thinning intensities was significant on Lufeng and Bailingtou forest area, mean stand volume current annual in crement of 16% to 30% and 31% to 40% thinning intensities was not significant, but higher than 10% to 15% thinning intensity. By analyzing the comprehensive stand factor, the best thinning intensity of Longgong and Bailingtou forest area was 16%to 30%and Lufeng forest areawas 31%to 40%.