Black bear habitats follow the distribution of beech and oak forests in northeastern Honshu Island. Black bears forage almost exclusively beech seed in a mast year. Therefore, appropriate bear population capacity would be calculated from the distribution of beech seed production. Beech crown can be easily identified by leaf flushing using the aerial photographs taken in early spring.

In this study, to draw beech crown map accurately, we propose a method to assess the optimum timing of beginning leaf expansion using monitoring photo data at fixed points in four different latitudes. We obtained the linear regression equation by the relationship between latitude and accumulated temperature. Furthermore, using the relationship between beech crown cover area and actual seed production, we construct an estimation model of seed production.