Bark stripping of Pinus contorta caused by moose and deer: wounding patterns, discoloration of wood, and associated fungi

Abstract

The aim of this study was to assess the extent of bark stripping wounds, subsequent wood discoloration, and associated fungi in 30-year-old Pinus contorta Douglas ex Loudon stems damaged by large game. In total, 90 trees were evaluated, and 170 bark stripping wounds of different ages (1–20 years) were measured. From each wound, wood samples were collected for subsequent fungal isolation. Thirty trees were cut to evaluate the length of the discoloration column. Of 170 injuries, 16 of them represented closed scars and 154 of them represented open wounds that exposed 4–4355 cm2 of sapwood. The wound length had a strong impact on the length of decay (r = 0.716); however, the spread of discoloration beyond the wound margin was limited (0–20 cm). The most commonly isolated fungus was Sarea difformis (Fr.) Fr. and, among the Basidiomycetes, Peniophora pini (Schleich.) Boidin. The results suggest that when planning to grow P. contorta in areas of Europe, the population size of large game animals needs to be considered, in view of potential risk of bark stripping damage.