Characteristics of bark-stripping of Hinoki cypress (Chamaecyparis obtusa) trees by Japanese black bear (Ursus thibetanus japonicus) and development of wood decay

Abstract

Characteristics of bark-stripping of Hinoki cypress (Chamaecyparis obtusa) trees by Japanese black bear (Ursus thibetanus japonicus) were investigated in Utsunomiya University Forest, and development of wood decay of the bark-stripped area was discussed. Mean DBH of bark-stripped trees in Hinoki cypress was 25.3 cm and larger than sound trees. Average maximum bark-stripped height was 1.5-2.0 m, and percentage of bark-stripped area was mostly 10-30%. Degree of wood decay on the surface of bark-stripped area and Pilodyn penetration increased with elapsed years after bark-stripping, while stress-wave velocity decreased. Wood decay on the surface progressed significantly in 10 years after bark-stripping.