云南松林分状况与松纵坑切梢小蠹危害的关系

Relationship between Stand Status of Pinus yunnanensis and Damage of Tomicus piniperda

通过对云南省 3个蠹害区的观测研究 ,证实云南松林分自身状况与松纵坑切梢小蠹危害关系密切。就云南松个体而言 ,根据林木生长分级标准 ,松小蠹主要危害被压木及濒死木 ,很少危害优势木及亚优势木 ;就林分整体而言 ,同一山体的东坡和南坡林分的蠹害程度重 ,西坡和北坡林分的蠹害程度轻。林缘蠹害程度明显高于林内 ;林分郁闭度与蠹害指数呈负相关 ,郁闭度越低蠹害越严重。研究证实 ,松小蠹有明显的趋光行为 ,即阳坡林分、林缘。

According to the study at three damage regions of pine shoot beetle, Tomicus piniperda in Yunnan, it verifies that the damage of T. piniperda closely relates to the stand status of Pinus yunnanensis. For individuals of P. yunnanensis, the beetle mainly attacks pressured and dying pines, and seldom attacks dominant and sub-dominant pines according to the growth levels of pines. For stands in a mountain, the damage in stands located on eastward and southward slopes is heavier than that in stands on westward and northward slopes, and the damage at the border of a forest is severer than that at the inside of a forest. There is a negative correlation between damage index and canopy density, that is to say the lower the canopy density is, the severer the damage is. The field investigation proves that the beetle has a relative remarkable phototaxis, so the beetle easily attacks sunny side stands, the border of forest and the stands with lower canopy density.