生育光条件を異にするシラカシ幼樹の冬季の光合成・蒸散特性
1985 年 35 巻 1 号 p. 123-131
詳細
1985 年 35 巻 1 号 p. 123-131
ENDO, Akio and OIKAWA, Takehisa (Inst. of Biol. Sci., Univ. of Tsukuba, Ibaraki). 1985. Effects of winter coldness on photosynthesis and transpiration of Quercus myrsinaefolia seedlings grown under different light levels. Jap. J. Ecol., 35 : 123-131. As the first step in the analysis of forest succession in the northern district of the Kanto plain, the characteristics of photosynthesis and transpiration of Quercus myrsinaefolia Blume (a kind of evergreen oaks) were investigated in winter using seedlings grown under the following four levels of light transmissibilities : 100%, 45%, 15% and 5%. Some light adaptive responses were clearly observed in the light-photosynthesis curve for the seedlings grown under relatively shaded conditions, especially under the 5% plot. The net photosynthesis rate at the equivalent light intensity, however, was lower under shaded conditions (5% and 15%) than under bright conditions (45% and 100%). The seedlings in all plots suffered from winter coldness which reduced the light-saturated maximum photosynthesis rate, but under the most shaded growth condition (5%), the reduction was postponed and its degree was minimized. These were regarded as a protection effect of the shading. Such an effect is expected on a forest floor under a dense canopy.
