Quantitative Evaluation and Modeling about ForestFloor Effects on Soil Acidification Induced by Acid Precipitation

在六高山和厚田神社进行了土壤酸化的实地调查。并探讨了土壤酸化与林木衰退的相关性。对于厚田神社，土壤采样点2，其中一些树木下降，只有酸化的四个采样点。但铝的溶出量低于鹫宫神社土壤，pH值与点2几乎相同。在六谷山，在12个地点收集了土壤样本。所有样品都被强烈酸化。我们按照土壤酸化程度对这些地点进行了排序。在12个样地中，这一等级与树木衰退程度几乎相关。通过浸灰，O层土壤和A层土壤的盐基饱和度（BS）都得到了恢复。在试验柱中，添加的钙主要吸附在O层土壤上，然后才到达O层土壤下面的A层土壤。浸灰使土壤中吸附的镁离子被淋溶，但穿透溶液中的pH保持其流入值。建立了评价石灰浸灰效果的数学模型。模拟结果与实验数据吻合较好，模拟结果较好地再现了上述现象，特别是O层土壤对钙的吸附和土柱流出液的pH无变化。

Field surveys about soil acidification were carried out at Rokko Mountains and Atsuta Shrine. And the relevancy between soil acidification and tree decline was discussed. For Atsuta Shrine, soil sampled at site 2, where some trees were declined, was only acidified among four sampling sites. But aluminum desolution was less than soil sampled at Washinomiya Shrine, pH which was almost as same as that at point 2. For Rokko Mountains, soil samples were collected at twelve sites. All samples were storongly acidified. We ranked these sites in order of the degree of soil acidification. This rank was almost correlated with the degree of tree decline at 12 sites.The liming effect was discussed experimentally by using the acidified soil in the Rokko Mountains. By the limning, the base saturation(BS) in both O layer soil and A layer soil were recovered. The added calcium was sorbed mainly on the O layer soil before reaching to the A layer soil set under the O layer soil in the experimental column. The liming leached out the magnesium ion previously absorbed in the soil, but the pH in the breakthrough solution kept its influent value. We developed the mathematical model for evaluation of liming effect. The simulation results fit well with the experimental data: those phenomena mentioned above was well reproduced especially on the calcium sorption in O layer soil and no change in pH in soil column effluent.The study for two years was summarized and published as the book-style report.