Abstract
Grassland, which is maintained by human activities, grazing or burning, occupied more than 12% of the land of Japan in 1850's. However, most of the grassland area shifted to coniferous plantation forest or secondary broad-leaved forest. The purpose of this study is to evaluate the magnitude and spatial variation of soil acidity change due to the land use change. Soil chemical analysis found that pedons with forest use history or gentle slope have higher soil acidity and higher carbon content. The criterion of soil acidity was determined by using attributes of land use and slope gradient. From the soil acidity evaluation map, the relatively high soil acidity areas, Class 4 and Class 3, were estimated, to account for 9.6% and 17.3% of Nakaizu-town, respectively.
