Leaf Structure and Photosynthetic Performance as Related to the Forest Succession of Deciduous Broad‐Leaved Trees 1

Photosynthetic response to light intensity and leaf anatomy was measured in trees of 30 seral deciduous broad‐leaved species native to the northern part of Japan. Early successional species showed high photosynthetic rates at high light saturation, while late successional species displayed low photosynthetic rates at high light saturation. The photosynthetic characteristics of mid‐successional or gap phase species were intermediate. After reaching the maximum photosynthetic rates, the initial decline in early successional species was faster than late successional species. There was a negative correlation between the leaf stable period and saturated photosynthetic rates. Early successional species have thicker leaves with a smaller cuticle ratio (i.e., ratio of cuticle width to leaf thickness) than late successional species. There was a positive correlation between cuticle ratio and leaf longevity. The percentage of air space in leaves of early successional species was larger than that in late successional species. A positive correlation was observed between the mesophyll surface area per unit area and saturated photosynthetic rates. In gap phase species, leaf sizes and maximum photosynthetic rates were smaller in seedlings than in saplings. However, these differences between seedlings and saplings were less frequently observed than in early and late successional species. The ecological importance of leaf structure and photosynthetic characteristics is discussed in relation to forest succession.