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[C-2.4 Studies on the Decline of Mountain Forest and Acid Deposition]

[Contact Person]

Takashi Yoshitake
Chief of Meteorological Hazard
Forestry and Forest Products Research Institute
Forestry Agency, Ministry of Agriculture, Forestry and Fisheries
1 Matsuno-sato, Kukizaki-machi, Ibaraki 305, Japan
Phone +81-298-73-3211, Fax +81-298-74-3720

[Total Budget for FY1993-1995]

14,364,000 Yen (FY1995 4,741,000 Yen)

[Abstract]

　In Mt. Nantai the existence of dead trees of Betula ermanii, Abies veitchii, A. mariesii and Tsuga diversifolia in the natural forest were clear. Because Mt. Nantai signs of frost damage on dead twigs of B. ermanii were recognized, the frost damage on tips of dead twigs in B. ermanii was recognized as one of causes of the death. Furthermore, damages by glaze and thunder were presented as a cause of death in A. veitchii. Remarkable damage of trees by deer in Mt. Nantai were found and especially Abies homolepis was seriously damaged in the natural forest. We collected and analyzed fog, rain and stemflow during warm seasons in 1993 and 1994. By results, existences of acid fog and acid rain at 1,700m above sea level at Mt. Nantai were recognized.
　Among the samples, a fog having pH 3.2, SO₄ density 66mg/l and NO₃ density 49mg/l were found. Leaves of B. ermanii discolored region of the leaf margin or whole on surface of the leaf and an unusual defoliation of B. ermanii has been seen during the growing season, late in August, every year.

[Key Words]

Forest Decline, Acid Fog, SO₄, NO₃, Betula Ermanii