地表火による樹幹の焼け焦げ程度からみた樹体の生死将来予測法確立への事例解析 : 被災2年後のスギ壮齢木健全度調査結果より

抄録

A large scale of forest fire has happened in Kamaishi peninsula, Iwate Prefecture, on April, 1987, by which a great deal of manmade Sugi forests were burned or damaged. There were 3 types in the forest fire; canopy fire, stem fire, and forest floor fire. In case of canopy fire or severe stem fire, damaged trees were killed perfectly. While, in case of forest floor fire, it was very difficult to estimate accurately about the future condition of damaged trees. Because, Sugi trees are not always die immediately after their stem was scorched. Basing on the after-2-years' condition of damaged trees, such as dead tree, weakened tree and healthy tree, the authors discussed the relationships between scorched degree and the fate of damaged trees, with use of several kinds of index from various parts of scorched stem, shown by figure-1. As the result of that, they could find the possibility of accurate estimation with some indexes, such as the ratio of scorched area to the total surface area in the foot part of damaged trees (S'/So') , that of scorched length to the girth length in the ground level of damaged trees (Cb/Co) and that of scorched area to the girth length of breast height (S+S'/C_<BH>) or to the girth length in the half of scorched height on stem (S+S'/C).