兴安落叶松林龄与耐害性关系的研究

STUDY ON THE RELATIONSHIP BETWEEN AGE AND TOLERANCE OF LARCH TO DENDROLIMUS SUPEASNS

分析兴安落叶松林龄及落叶松林木与落叶松毛虫耐害性的关系，提出了以林木材积连年生长量损失的百分数作为度量林木耐害性的指标。通过灰色关联分析，得出了在一定年龄范围内（１５～４５ａ），兴安落叶松林木对落叶松毛虫的耐害性随林龄的增加而增强，并且这种作用在高失叶率下更明显的结论；同时也指出了造成这种情况的原因，即在这一年龄段兴安落叶松林木的材积连年生长量随林龄增加而迅速增高。落叶松林木年龄越大，抗落叶松毛虫干扰的能力越强。因此，林龄增大，防治指标应提高。

The paper put forward an index-the damaged percentage of current annual increment of volume,with which the tolerance of Larch to D. superans(Bulter) can be measured. Using Grey Relative Analysis,the authors found that within the scope of given age (15～45a) the tolerance of Larch to D.superans increase with age increase, and the effect is more obvious in heavy defoliation,and also pointed out that the cause is the quick increase of the current annual increment of volume with age increase.Thus the index of control should increase with age increase.