The effect of neighboring tree size and distance on mortality of trees in Tadasu-No-Mori Forest

Abstract

We measured all woody stems 10 cm D_BH in the whole area(9.08 ha)of Tadasu-No-Mori Forest in 1991 and 2002.and examined the effect of neighboring tree size and distance on mortality rate of trees during 11 years. Small size class trees with 10-15 cm D_BH at 5-10 m distance from their nearest upper trees had higher mortality rates than those at 0-5 m distance. Large size class trees with larger than 30 cm D_BH had lower mortality rates when they were over 10 m distant from their nearest upper trees. Medium size class trees with 15-30 cm D_BH of Celtis sinensis and Zelkova serrata were much influenced by their nearest upper trees. This result suggested these species required the space with low density of the upper trees in order to reach the canopy layer.