1977-78年噴火後の有珠山における植物の侵入と回復 : 予報
スポンサーリンク
概要
- 論文の詳細を見る
The summit caldera of Usu volcano was completely devastated by the volcanic eruption of 1977-78. Projections of stones, ashfalls, tremors and ground deformations are among the factors which caused a great deal of damage to the plants. The following remarks are issued of surveys carried in 1980-82. It was found that in areas where the burying was not too significant, herbaceous species with underground storage organs and most of the trees survived ; The grasses, Polygonum sachalinense, Petasites japonicus and Equisetum arvense and the trees, Populus rnaximozviczii, Acer mono and Ulmus davidiana appeared to be the best survivors. In some of the areas thickly covered with ash and pumice, the Primary Invasion started quickly (probably in 1979-80). The herbaceous pioneer plants originated mostly from proximate surviving mother-plants. The seeds were transported by the wind and also, to a large extent, by the water along the rills and gullies. The pioneer trees originated almost exclusively from light anemochorous seeds coming from relatively undisturbed forest outside the caldera. The Salicaceae species are the best represented among the pioneer trees. The mosses invaded the ash-pumice desert along with the phanerogams. In particular habitats such as the fumarollic zones, only mosses and blue algae are found. The plant Recovery and Invasion do not seem to be limited by the disseminule supply or the low nutrient value of the new volcanic deposit, but by intensive geomorphic processes such as slope-wash mud and debris flows. These started almost immediately after the ash fallout and were still active in 1982.
- 北海道大学の論文
- 1983-08-15