火山活動が桜島の周辺斜面における森林の遷移と土壌浸透能に及ぼす影響
キーワード:
Volcanic activity,
Peripheral slopes of Sakurajima Volcano,
Succession of woody vegetation,
Water infiltration rate
2018 年 23 巻 2 号 p. 35-41
詳細
2018 年 23 巻 2 号 p. 35-41
We clarify the effect of volcanic activity on the succession of woody vegetation in relation to the growth environment and the effect on water infiltration rates on the peripheral slopes of Sakurajima Volcano, Japan. We selected ten plots (25 m2) on the peripheral slopes of the volcano located 7-15 km from the Minami-dake crater and conducted a field study. The results showed that the maximum tree height and diameter at breast height, the number of trees and tree species, breast height cross-sectional area, Fisher-Williams index of diversity, forest soil thickness, and water infiltration rate all increased with distance from Minami-dake. However, the thickness of the volcanic ash layer deposited since the 1914 Taisho eruption decreased with distance. The succession of woody vegetation and the water infiltration rate in these plots were not at the level of a climax forest. Overall, plots further from the crater had a better environment for vegetation growth. To prevent a decrease in the water infiltration rate from the volcanic activity of Sakurajima, it is essential to promote soil development by planting trees resistant to volcanic activity.
