BLACK BEAR DAMAGE TO LODGEPOLE PINE IN CENTRAL OREGON

摘要: Black bear (Ursus amerlcanus) damage to 108 lodgepole pine (Pinus contorta) trees was found in a mixed conifer habitat central Oregon. No of three other species were injured. Eighty-nine percent the occurred same year. Nearly 20% freshly damaged had bark removed from more than 75% circumference and, judging fate prior years, probably succumbed. bears americanus) feed on sapwood number coniferous some habitats, have shown def- inite preference for certain species. In western Washington and Oregon, Douglas-fir (Pseudo- tsuga menziesii) is reported be selected frequently (Levin 1954, Childs Worthington 1955, Hartwell 1973). northwest California, extensive has been observed redwood (Sequoia sempervi- rens) (Glover 1955). Additional reports indicate white spruce (Picea glauca) Kenai Peninsula Alaska (Lutz 1951), monticola) interior British Columbia (Molnar McMinn 1960), balsam fir (Abies balsamea) Maine (Zeedyk 1957), Engelmann engelmannii) Yellowstone Park (Contor subalpine (A. lasiocarpa) whitebark al- bicaulis) Montana (Tisch 1961). Elsewhere U. americanus larch (Larix occidentalis), P engelmannii (Mason Adams 1989). Damaged located course stud- ies served as centers intensive searches ad- ditional by bears. A search con- ducted each tree, or patch trees, cardinal directions up 500 m. Each newly identified site center (~~~k~l cowan 1971, M~~~~ ~d~~~ further fashion. Species, diam- eter at breast height (d.b.h.), maximum 19891, eastern (Poelker stripped ground line recorded Hartwe'' we describe evidence tree. To classify degree injury, exclusive feeding F! contorta a,erage extent removal around circum- ference main stem estimated assigned