Impact of volcanic activity in the Showa crater since June 2006 on growth of Japanese black pines on Sakurajima Volcano, Japan

Abstract

To study the impact of volcanic activity in the Showa crater since June 2006 on growth of Japanese black pines on Sakurajima Volcano, we conducted investigations of growth rings of Japanese black pines and of soil pH and volcanic ash deposition during 2003 and 2010. We established three experimental sites at 330 m, 70 m and 20 m above sea level, respectively. These experimental sites are most influenced by volcanic activity from the Showa crater. The annual average volcanic ash thickness at the experimental sites during the period of heightened volcanic activity (2008 to 2010) was greater than that during the period of low activity (2003 to 2007). Moreover, the growth ring width index of Japanese black pines during the period of low activity was greater than that during the period of heightened volcanic activity. It is clear that volcanic activity in the Showa crater since 2008 has affected the growth environment of Japanese black pines.