Browsing ungulates - An important consideration in dieback and mortality of Pacific yew (Taxus brevifolia) in a northeastern Oregon stand

We examined 712 Pacific yew stems in a stand in the Blue Mountains to asses s causes for yew dieback and mortality. Many living stems were dead or part ially dead: 66% of the stems were <50% dead, 17% were >50% dead, and anothe r 17% of the stems were dead. A high proportion (89%) of the mature stems h ad wounds. Assessment of wounding indicated that bark stripping by deer and elk was the primary cause and suggests that this factor is important in di eback and death of Pacific yew in the study area. Counts of seedlings and a ssessment of seedling age showed that most seedlings were between 1 and 3 y ears old with substantially fewer in the 3- to 6-year age class. Older seed lings were scarce. Severe damage to mature stems and lack of seedling recru itment (presumably because of ungulate browsing) raise questions about the continued viability of Pacific yew in this area.