论文部分内容阅读
通过对马尾松人工模拟剪叶,在30%以上时,对当年和翌年材积生长量都有影响。剪叶越多,影响越大,平均生长率减少4.7%,影响达2年。瑞安市马尾松毛虫3级以上虫灾危害松林一次,平均每年每公顷损失木材蓄积量0.7762m~3(第1年0.4374m~3,第2年0.3389m~3)、松针重量7.086吨,损失价值541.58元。本试验为制订防治指标和科学管理提供依据。
Through artificial simulation of Pinus massoniana cut leaves, when more than 30%, on the volume growth of the current year and the following year have an impact. The more leaves are cut, the greater the impact is, the average growth rate is reduced by 4.7% and the impact is up to 2 years. In the pine forest of Ruian City, pests affected more than 1 grade, the average annual loss of timber per hectare was 0.7762m ~ 3 (0.4374m ~ 3 in the first year and 0.3389m ~ 3 in the second year), the weight of loose needles was 7.086 tons, the loss value 541.58 yuan. This experiment provides the basis for formulating prevention and control index and scientific management.