Relation between tree decline of Kojii and Arakashi, and soil pH in shrine forest in Osaka Prefecture

Abstract

A precious forest of Migukurumitama shrine occupying Kojii (Castanopsis cuspidate) and Arakashi (Quercus glauca) in southern part of Osaka Prefecture have been protected for many years. The forest is registered in one hundred selections in forests of Osaka. However, survey at the site showed tree decline of both species. Soil chemical analysis revealed low soil pH value. In addition, strong statistical correlation (Pearson correlation coefficient, rp = -0.719, Spearman rank correlation coefficient, rs=-0.730) was found between the decline score and the soil pH around Kojii trees.