Persistence of western hemlock and western redcedar trees 38 years after girdling at Cat Island in southeast Alaska.

Abstract

Dead western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex. D. Don) trees were examined 38 years after intentional girdling (cuts made into wood around the bole) at Cat Island, Alaska, to describe their condition as wildlife habitat. All but 1 of 42 hemlock had boles broken at or below 30 feet. The wood of all standing boles and boles on the forest floor was thoroughly degraded by brown rot fungi, white rot fungi, or both. Western redcedar snags were either standing with primary limbs intact, or were down with boles broken at the girdle. Snags of neither species had cavities excavated by animals. Although only four Sitka spruce (Picea sitchensis (Bong.) Carr.) were killed in the study, two were still standing, both having been extensively used by cavity excavating animals. Dead hanging bark of all three tree species may provide roosting habitat for bats.

Citation

Hennon, P.E.; Loopstra, E.M. 1991. Persistence of western hemlock and western redcedar trees 38 years after girdling at Cat Island in southeast Alaska. Res. Note PNW-RN-507. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 8 p