白龙江林区油松林分因子对中华松针蚧危害的影响

目的 通过研究油松林分因子对中华松针蚧(Matsucoccus sinensis Chen)发生不同危害程度之间的影响，为白龙江林区中华松针蚧的防控技术提供理论指导。 方法 在白龙江林区选取林龄相对一致(约25年)的油松纯林为研究对象，调查样地内草本盖度、林分密度、郁闭度、枝下高、树高、冠幅及胸径7个林分因子及中华松针蚧的虫情指数，依据样地内虫情指数的分组，分析不同林分因子与样地内虫情指数的关系。 结果 表明，草本盖度、林分密度、树高、枝下高、胸径及冠幅6个林分因子对中华松针蚧发生危害程度有显著影响，郁闭度无显著影响。通过多重回归分析及逐步回归分析筛选出影响中华松针蚧发生危害程度的关键林分因子为草本盖度、林分密度及枝下高。草本盖度对中华松针蚧虫情指数影响极显著(P < 0.01)，相关性分析得出二者变化具有相反的趋势，随着草本盖度的增加，虫情指数降低。林分密度对中华松针蚧虫情指数的影响达到极显著水平(P < 0.01)，其低密度林分(381～763株·hm−2)受中华松针蚧的危害加重，林分密度(> 763株·hm−2)的油松林受其危害程度较轻。不同枝下高对中华松针蚧虫情指数的影响差异极显著(P < 0.01)，枝下高较高(3.5～4.4 m)的油松受中华松针蚧危害严重，枝下高较低(1.1～3.5 m)的油松林受危害程度低。 结论 油松纯林的林分因子与中华松针蚧发生危害关系密切，其中草本盖度、林分密度及枝下高3个林分因子影响中华松针蚧发生危害最为显著。建议在中华松针蚧的防治工作中，可通过调整林分因子进行合理的修枝、间伐等营林措施以达到控制危害发生。

Effects of Stand Factors of Pinus tabulaeformis Stand on Damage of Matsucoccus sinensis in Bailongjiang Forest Area

Objective To study the effects of stand factors of Pinus tabulaeformis stand on the damage severity of Matsucoccus sinensis, so as to provide reference for the prevention and control of M. sinensis in Bailongjiang forest area. Method Pure P. tabulaeformis stands with relatively uniform age structure (about 25 years-old) were selected as the object in Bailongjiang forest area, and seven stand factors, including herb coverage, stand density, canopy density, tree height, height under branch, DBH and crown width, and the pest severity index of M. sinensis were investigated in the sample plots. The relationship between stand factors and pest severity index in the plot was analyzed. Result The results showed that six stand factors, i.e. herb coverage, stand density, tree height, height underbranch, DBH and crown width, had significant effect on the damage severity of pure P. tabulaeformis stand, but the canopy density showed less effect. Through multiple regression analysis and stepwise regression analysis, the key stand factors affecting the damage severity of M. sinensis were found to be herb coverage, stand density and height under branch. Herb coverage had a significant effect on the pest severity index of M. sinensis (P < 0.01). The correlation analysis showed that with the increase of herb coverage, the pest severity index decreased. The effect of stand density on the pest severity index of M. sinensis was very significant (P < 0.01), and the damage of low density stand (381~763 trees·hm−2) was aggravated by M. sinensis, the stand density (>763 trees·hm−2) of P. tabulaeformis stand was less damaged. There was a significant difference in the effect of height under branch on the pest severity index (P < 0.01), the stand with the height under branch of 3.5~4.4 m was seriously damaged by M. sinensis, while the stand with lower height under branch (1.1~3.5 m) was less damaged. Conclusion The stand factors of pure P. tabulaeformis stand are closely related to the occurrence and damage of M. sinensis, and the three stand factors (herb coverage, stand density and the height under branch) have the most significant effect on the occurrence and damage of M. sinensis. It is suggested that adjusting the stand factors, pruning and thinning are effective in preventing and controlling the damage of M. sinensis.