Growth, Net Photosynthetic Rate, Nutrient Status and Secondary Xylem Anatomical Characteristics of Fagus crenata Seedlings Grown in Brown Forest Soil Acidified with H2SO4 Solution

Dry matter production, net photosynthetic rate, leaf nutrient status and trunk anatomical characteristics of Fagus crenata seedlings grown in brown forest soil acidified by adding H₂SO₄ solution were investigated. The soil acidification leaded to decreased (Ca+Mg+K)/Al molar ratio in the soil solution. Dry mass per plant of the seedlings grown in the soil treated with H+ at 120 mg.L-1 was significantly reduced compared with the control value at 0 mg-L-1. When net photosynthetic rate was reduced in the seedlings grown in the soil treated with H+ at 120 mg-L-1, the carboxylation efficiency and maximum net photosynthetic rate at saturated CO₂-concentration were lower than the control values. The addition of H+ to the soil at 120 mg-L-1 induced a reduction in the concentration of Ca in the leaf. By contrast, the concentration of Al in the leaf was increased with increasing the amount of FT added to the soil. The annual ring formed in the seedlings grown in the soil treated with H+ at 120 mg-L-1 was significantly narrower than that at 0 (control), 10, 30, 60 or 90 mg-L-1. Based on the results obtained in the present study, we conclude that Fagus crenata is relatively sensitive to a reduction in the (Ca+Mg+K)/Al molar ratio of soil solution compared with Picea abies.