1977年の有珠山火山降下物の堆積に対する抵抗力の樹種による違い

抄録

Deciduous broad-leaved trees were severely damaged by the 1977 eruption of Mt. Usu. The degree of damage, however, was different among tree species. In intermediately disturbed sites, many trees of excurrent growth species (e. g., Populus maximowiczii) produced a few epicormic sprouts, but almost all trees died within 3 years after the eruption. Conversely, many decurrent growth species (e. g., Acer mono) showed active epicormic sprout development and consequently survived for at least 8 years. Survivors gradually decreased their heights by consequence of withering their epicormic sprouts at their tops. Such responses are perhaps accomodative to the condition of being deeply buried by volcanic deposits and therefore restricted on water absorption as well as results of severe stress. In addition, such responses are closely related to the growth habit of decurrent growth species characterized by weak apical control, therefore, it was suggested that the stem survival potential of excurrent growth species to volcanic deposits should be extremely constrained by weak apical control, therefore, it was suggested that the stem survival potential of excurrent growth species to volcanic deposits should be extremely constrained by their own tree architecture characterized by strong apical control.