Viewpoint: Western juniper expansion: is it a threat to arid northwestern ecosystems?

  title={Viewpoint: Western juniper expansion: is it a threat to arid northwestern ecosystems?},
  author={Alan J. Belsky},
  journal={Journal of Range Management},
  • A. J. Belsky
  • Published 1996
  • Environmental Science
  • Journal of Range Management
Many ranchers, rangeland managers, and range scientists in the Pacific Northwest consider western juniper (Juniperus occidentalis Hook.) to be an invading weed that reduces water infiltration, dries up springs and streams, increases erosion, reduces biodiversity, and reduces the quality and quantity of forage for livestock and wildlife species. Although there is little scientific evidence supporting most of these beliefs, they are currently being used as rationales for controlling juniper on… 
Characteristics of western juniper encroachment into sagebrush communities in central Oregon
Western juniper (Juniperus occidentalis) woodlands in Oregon have expanded four-fold from 600,000 ha in 1930 to > 2.6 million ha, often resulting in the reduction and fragmentation of sagebrush
Recent Juniperus occidentalis (Western Juniper) expansion on a protected site in central Oregon
It is suggested that the role of biological inertia of both anthropogenic and natural means may have had a profound effect on the J. occidentalis ecology of the Horse Ridge Research Natural Area in central Oregon over a 23-year period.
Impacts of western juniper on plant community composition and structure
Western juniper (Juniperus occidentalis Hook.) has been actively invading shrub steppe communities during the past 120 years. The majority of these stands are still in transition, from early open
Relationships Between Western Juniper (Juniperus Occidentalis) and Understory Vegetation
Findings by researchers in other states that western juniper influences plant community structure and productivity, and removal of western junipers might reverse these changes in structure, but also might increase opportunities for invasion of cheatgrass are supported.
Reversing the Woodland Steady State: Vegetation Responses During Restoration of Juniperus-Dominated Grasslands with Chaining and Fire
Junipers (Juniperus spp.) are native woody shrubs that have expanded beyond their normal historical ranges in the western and southwestern United States since the late 1800s (Johnson 1962; Burkhardt
Managing Native Invasive Juniper Species Using Fire1
Junipers (Juniperus spp.) are native woody shrubs that have expanded beyond their normal historical ranges in the western and southwestern United States since the late 1800s. Most ecologists and
Age Structure and Expansion of Piñon-Juniper Woodlands: A Regional Perspective in the Intermountain West
Numerous studies have documented the expansion of woodlands in the Intermountain West; however, few have compared the chronology of expansion for woodlands across different geographic regions or


Causes of Juniper Invasion in Southwestern Idaho
Invasion of western juniper into vegetation dominated by mountain big sage- brush and perennial bunchgrass on the Owyhee Plateau of southwest Idaho appears to be directly related to cessation of
Demography and fire history of a western juniper stand.
The age, density, and fire history of western juniper trees growing on range sites of contrasting potentials were investigated and soils of many of these stands appear to be adapted to support communities of big sagebrush (Artemisia tridentata Nutt.)/ bluebunch wheatgrass.
Bird populations in four vegetational types in central Oregon.
A long-term study of birds to obtain baseline population data in relatively undisturbed major plant types was started in Deschutes County, Oregon, in 1971. Four study areas were established. The big
Runoff and erosion in intercanopy zones of pinyon-juniper woodlands
It is suggested that the following hypotheses proposed about runoff and erosion in other semiarid landscapes are also true of pinyon-juniper woodlands:Runoff amounts vary with scale: runoff decreases as the size of the contributing ares increases and provides wore opportunities for infiltration, and infiltration capacity of soils is dynamic.
Plant Succession Following Control of Western Juniper (Juniperus occidentalis) with Picloram
Investigation of dynamics of herbaceous vegetation after control of western juniper trees with picloram pellets emphasized the need for comprehensive manipulation of all components of the vegetation when range improvement is attempted.
Water Yield Improvement Potential by Vegetation Management on Western Rangelands
Increasing water for onsite and offsite uses can be a viable objective for management of certain western rangelands. One approach utilizes water harvesting techniques to increase surface runoff by
Herbage production following tree and shrub removal in the pinyon-juniper type of Arizona.
Herbage production was evaluated after overstory removal from different sites within the pinyon-juniper type. Average annual production varied from 43 to 643 kg/ha before treatment and 715 to 3,703
Runoff and Sediment Yields from Runoff Plots on Chained Pinyon-Juniper Sites in Utah
and 150~cm depths in the woodland is due in part to deeper root penetration by the pinyon and juniper trees. Crested wheatgrass roots are concentrated in the surface 45 cm of soil profile, while
Potential soil erosion of selected habitat types in the high desert region of central Oregon.
The purpose of this study was to investigate ecological land units within the Bear Creek watershed, 65 km east of Bend, Oregon, in terms of their susceptibility to surface water intrusion.
Infiltration and erosion studies on pinyon-juniper conversion sites in Southern Utah.
bleached; however, treated plants reached this stage 3 to 4 weeks earlier than the controls. Although silvex-treated plants were generally lower in miserotoxin than 2,4,5-T-treated plants, the