Acid deposition on pine needles in Mt. Gokurakuji, Hiroshima Prefecture, Japan

Abstract

Acid deposition of atmospheric constituent influence on the vicinity of the exhaust source. In this study, acid deposition on pine needles was investigated at the point of 150m a.s.l. on the south-facing slope (polluted area) and at 550m point on the north-facing slope (unpolluted area) of the Mt. Gokurakuji, Hiroshima Prefecture. Equivalents of NO₃^- and SO₄^2- were detected 3.22 (μeq/20g dry weight) and 1.73 on the south-facing slope, and the NO₃^- was especially high. On the other hands, the NO₃^- and SO₄^2- were detected 0.51 and 0.54 on the north-facing. An obvious difference was seen compared with the south-facing slope. It suggests that acid deposition, especially NO₃^-, influence decline of pine forests on the south-facing slope of the region studied.