Abstract
Utah junipers (Juniperus osterosperma (forr.)) are the dominant trees in the landscape of the southwestern states (35 million hectares). In Utah, the pinyon-juniper woodland represents 28.6% of the vegetation and are an important part of the aesthetic value of the Utah national parks. Over the past several years, extensive foliar damage has occurred to Utah juniper, yet little foliar damage has been observed in Natural Bridges National Monument, Canyonlands National Park, Arches National Park, Mesa Verde National Park and Colorado National Monument. The characteristic pattern is for the distal foliage to become chlorotic and die. Mortality progresses along twigs until whole branches or even the entire tree dies. The cause for the foliar damage is unknown. The loss of juniper trees in the national parks in southern Utah would have a dramatic ecological impact and would be an aesthetic blight in the parks. The purpose of this investigation is to determine the cause of the die-off of Utah junipers and suggest management options concerning the juniper die-off problem.