In February 2017, an avalanche destroyed 4.8 hectares of subalpine forest in the northern Akaishi Mountains, Japan. We investigated the size and type of damaged trees at the avalanche site and measured the number and diameter of roots exposed on the root plates. The type of tree damage was predicted by comparing the magnitude of the avalanche’s fluid force (Pa), resistance to trunk‐breaking (Ps) and resistance to uprooting (Pr). As a result, it was predicted that when the avalanche hits a standing tree only once, Ps

Key words

avalanche, type of damaged tree, trunk breakage, uprooting, mechanical analysis