Use of Wild Sugi (Cryptomeria japonica) Trees in Mikawa Area, Aga Town, Niigata Prefecture, Japan

Abstract

Scattered populations of pollarded wild sugi (Cryptomeria japonica) trees in Tsunagi and Nakanosawa hamlets, Niigata Prefecture, Japan, have multi-forked trunks that branch more than 2 m above ground level. The objectives of this study were to document historical uses of wild sugi trees, including pollarding, determine why pollarding was practiced, and explain the continued persistence of pollarded trees within the study area. During the Edo era (1630-1868), wild sugi trees were selectively felled for a variety of purposes, including building materials, ship materials, round containers made of wood sheets, and roofing. Building materials were cut exclusively from the upper parts of trees, and the height of cut stems in extant pollarded trees coincides approximately with the depth of snow cover in the region. Until 1965, trees in private forests were felled and removed on sleds when the snowpack was firm and deep. Thus, pollarding may have originated as a result of winter felling on deep snowpacks. The bases of some pollarded trees were harvested for lumber, although only trees with a long and thick base were highly valued. The remaining trees persist in deciduous hardwood forests and sugi plantations due to their low economic value.