Use of pollarded natural Cryptomeria japonica trees in Otokoro, Itoigawa City, Niigata Prefecture

Abstract

In Niigata Prefecture, Japan, there are scattered populations of natural sugi (Cryptomeria japonica) trees with multi-forked trunks that branch more than 2 m from the ground. Possible relationships between the unusual shape of these trees and uses by local people were investigated through a literature search, interviews with inhabitants of Otokoro hamlet, Itoigawa City (the site of a community forest hosting such trees) and examination of local houses. The findings show that natural sugi has been used for constructing houses in the hamlet. Further, it has been harvested by manually cutting selected trunks of suitable size for building materials, bucking them with saws, and carrying them out on sleds in March and April, when the snowpack is firm and deep. Thus, the trunks have been felled at relatively high positions, leading to the unusual multi-forked trunks. It is thought that the populations of natural sugi trees with the unusual shape remain because they are in a community forest that has beenusedmostlybytheresidentsof the local hamlet since the Edo era (1603­-1868).