MATURE TREE EFFECT OF ACER MONO ON SEEDLING MORTALITY DUE TO INSECT HERBIVORY

Mature tree effects on the mortality and herbivory of current-year see dlings were investigated in a common subcanopy species, Acer mono Maxi m., in a cool temperate mixed forest. The mortality of natural seedlin gs under the canopy with A. mono layers was greater than that under th e canopy without them. Also, the mortality of seedlings in planters lo cated under the crown of an A. mono tree was at least 1.8 rimes greate r than that of those in planters about 5 m away from the crown edge. P yrrhalta fuscipennis (Coleoptera: Chrysomelidae) and other specialist insects, having probably dropped from A. mono crowns, were more freque ntly observed in planters under A. mono crowns than in those far from the crowns. Leaf area loss due to specialist herbivores was probably t he main cause of increase in the mortality of A. mono seedlings close to conspecific adults. It is implied that seedling predation by specia list herbivores coming from parent trees is a substantial factor promo ting local seed dispersal of A. mono.