Tree Decline and Soil Acidification in the Japanese Cypress (Chamaecyparis obtusa) Grove at the Awaga Shrine in Hyogo, Japan

Abstract

Japan’s Buddhist temples and Shinto shrines have long histories. Many are surrounded by sizable groves that have been carefully preserved and are regarded today as sacred. We investigated whether soil acidification might be causing tree decline at the Awaga Shrine (Hyogo, Kansai, Japan). The shrine site is more than 1000 years old and has a large sacred grove of Japanese cypress (Chamaecyparis obtusa). This species has extremely durable wood, and some buildings built with it have stood for more than 1000 years. We found serious to severe tree decline in the Awaga cypress grove. The shrine’s soils have undergone acidification, which was significantly correlated with cypress decline. Chemical analysis of the shrine’s soils suggests that their nutritional status has declined relative to the national average. This suggests that soil acidification may be related to the cypress decline.