马尾松毛虫灾变发生类型与地貌及植被特征间对应分析

Correspondence analysis between occurrence type of Dendrolimus punctatus and topographical and vegetative features.

The relationship between the occurrence type of Dendrolimus punctatus and the geographical and vegetative features in subcompartments was analyzed using correspondence anaysis and shown by a figure of cluster. The results showed that the majority subcompartments in which D. punctatus occurred frequently were at low elevation and low slope,and distributed among low hills or middle hills,while the subcompartments at high elevation or high slopes,or in low mountains or middle mountains were safe-type. The subcompartments with only one dominant species,especially Pinus elliottii ,were easily attacked by D.punctatus . The subcompartments in conifer and broadleaf mixed forest had less insect pests than those in conifer mixed forest.