The crown shape of an evergreen oak,Quercus glauca, in a hardwood community

The spatial pattern of the crown spread ofQuercus glauca in a hardwood community was investigated in order to consider the effect of the patterns on its survival in a secondary hardwood community. The shape of a crown was defined by the spatial spread of the leaves (PCM crown), and by the spread of their branches (elliptic cylinder crown). The stem volume growth rate of a tree was strongly correlated with the corresponding total leaf area, which was then significantly correlated with the defined crown volume. This indicated that the stem volume growth depended on the crown volume as well as the total leaf area. An increase in leaf area was largely attained by the spatial volume of the crown, not by an increase in the leaf area density. The leaves inside the crown began to spread horizontally relative to the crown size as the total leaf area and tree size increased. On the other hand, for the crowns representing the branch spread, the crown shape (crown width/depth ratio) did not differ by internal leaf area and tree size. Such a spatial pattern was likely to be adaptive for a species that dominates at a mid-stage of secondary sere.