Historically fire has been the primary disturbance factor in the sagebrush-steppe. The settlement of the West by Euro-Americans, grazing by domestic livestock, and the concomitant spread of invasive species have altered the historical fire regime. Understanding the long-term vegetation structure and fuel succession of the various sagebrush-dominated communities of this...
We are at risk of losing the sagebrush steppe in the floristic Great Basin to the invasion of Bromus tectorum L., cheatgrass. The floristic Great Basin includes the Central Basin and Range, the Northern Basin and Range, and the Snake River Plain. The Great Basin receives most of its precipitation...
Identifying habitat and spatial requirements of wildlife species across multiple spatial scales is a challenging, yet crucial component of wildlife management. Habitat use of bats is particularly difficult to study, and managing habitat to conserve bats is especially challenging because bats are highly vagile organisms that exploit several different types...
Crested wheatgrass (Agropyron cristatum [L] Gaertm), an introduced bunchgrass, has been seeded on over 5 million hectares of degraded rangeland in western North America because it establishes more readily than native bunchgrasses. Because crested wheatgrass stands are associated with native species displacement and low biological diversity, there is substantial interest...
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A BRIEF INTRODUCTION OF THE ECOLOGY OF THE SAGEBRUSHSTEPPE IN SOUTHEASTERN OREGON
The historical function of fire in sagebrush steppe has been altered by 19th century overgrazing, active fire suppression, annual grass invasion and encroachment of woody species. The significance of fire to these systems is known, but research on long-term fire effects are limited. The Sheep Rock management unit of the...
The sagebrush steppe ecosystem of the Columbia Plateau has become degraded by a long history of alternative land use and associated perturbations. Protection of remnant stands of intact sagebrush steppe currently relies upon their preservation within the nation's network of parks and protected-areas. The John Day Fossil Beds National Monument,...
Biological plant invasions are diminishing the ecological integrity and function of ecosystems worldwide. A primary example of this is in the Great Basin of the United States, where invasive annual grasses, like cheatgrass (Bromus tectorum L.) and medusahead (Taeniatherum caput-medusae L. Nevski), are dominating many sagebrush-steppe ecosystems. In these invaded...
Intact sagebrush communities in the Great Basin are rapidly disappearing due
to invasion of non-native plants, large wildfires, and encroachment of pinyon pine
and juniper woodlands. Land management options include the use of prescribed
fire, grazing, herbicides and mechanical treatments to reduce the potential for
wildfire and restore plant communities....
This white paper outlines interim guidance for development of Oregon Department of Fish and Wildlife habitat mitigation recommendations associated with renewable energy development and associated infrastructure or other landscape scale industrial-commercial developments in greater sage-grouse habitat in Oregon. This guidance is interim until empirical data are available that quantify the...
The semi-arid sagebrush steppe ecosystem is one of the largest biomes in
North America. The steppe provides critical habitat and forage for wildlife and is
economically important to recreation and livestock industries. However, the ecosystem
is threatened primarily due to several negative effects associated with expansion of the
exotic annual...
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David A. Pyke Patricia S. Muir
The semi-arid sagebrushsteppe ecosystem is one of
Fire is an important disturbance mechanism in big sagebrush (Artemisia
tridentata) communities, yet little is known about wildlife population dynamics during
post-fire habitat succession. I estimated the abundance of small mammals and birds in
relation to fire history in mountain big sagebrush (A.t. spp. vaseyana) communities on the
Sheldon National...
Sagebrush steppe ecosystems in the Great Basin have become increasingly threatened by the proliferation of cheatgrass (Bromus tectorum L.), an invasive annual grass. Diverse sagebrush and perennial bunchgrass landscapes can be converted to homogenous cheatgrass grasslands mainly through the effects of fire. Although the consequences of this conversion are well...
A causative factor in declining greater sage-grouse (Centrocercus urophasianus)
populations is reduced annual recruitment due to poor habitat quality. Sage-grouse
population decline is concurrent with a decline in the extent and quality of the
sagebrush (Artemisia sp.) biome. However, current research has shown a positive
relationship between sage-grouse brood and...
Expansion of Juniperus occidentalis into the sagebrush steppe has resulted in significant changes in understory composition. A consequence of increased J. occidentalis dominance may be a depletion of the seed bank. The potential for depletion is problematic because a reduction in the amount of species available from the seed bank...
Western juniper (Juniperus occidentalis) cover has more than doubled within the last century and currently occupies over 9 million acres in the Intermountain West. Encroachment has altered the spatial distribution of soil nutrients and plants in these systems, forming nutrient enriched 'resource islands,' under tree canopies. The purpose of this...
In the western United States, sagebrush (Artemisia spp L.) dominated rangelands are extensive, accounting for approximately 63 million ha. The Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young) alliance is found in more xeric environments, occupying the largest area of the big sagebrush complex in areas within...
Juniper is a native species to Oregon and confers ecological benefits to wildlife when it is at savannah and transitional densities. Its range and extent have fluctuated with climatic change, but the current range expansion is unprecedented in its extent. The range expansion has been associated with the degradation of...
Pygmy rabbits (Brachylagus idahoensis) in Oregon and Washington are a sagebrush (Artemisia tridentata spp.) obligate species of concern because of declining populations and extirpation from much of their range. Efforts are underway to establish a captive bred population of the Columbia Basin pygmy rabbit in Washington state for reintroduction into...
Anthropogenic land use alterations such as livestock grazing and fire
suppression have greatly altered sagebrush grasslands of the Great Basin,
facilitating invasion of exotic annuals, increases in woody species, and losses of
native species. Much of the current research surrounding wildland and prescribed
fire in sagebrush dominated ecosystems has focused...
This study consisted of two research projects in the Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh) alliance, the most extensive of the big sagebrush complex in the Intermountain West. In the first project, we intensively sampled 107 relatively undisturbed, late seral Wyoming big sagebrush...
Within A rtemisia tridentata ssp. wyomingensis Nutt. (Wyoming big sagebrush)
communities of the Great Basin, lands dominated by the exotic annual grass Bromus
tectorum L. (cheatgrass) are increasing at an alarming rate. Carbon applications, which
reduce plant-available soil N, have been suggested as a way to give native vegetation a...
Since European American settlement of the Intermountain Region, dramatic changes in vegetation composition and structure have occurred in the sagebrush steppe ecosystem. Western juniper (Juniperus occidentalis spp. occidentalis Vasek), although indigenous to the Intermountain Region, has increased since the late 1800s. Considerable work has been done documenting juniper woodland expansion...
Western juniper has rapidly expanded into sagebrush steppe communities in the Intermountain West during the past 120 years. This expansion has occurred across a wide range of soil types and topographic positions. These plant communities, however, are typically treated in current peer-reviewed literature generically. The focus of this research is...
Published June 1997. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Water potential, leaf conductance, growth, nitrogen
content, and seedling survival of Wyoming Big Sagebrush
(Artemisia tridentata ssp. wyomingensis) following
defoliation of the herbaceous understory were assessed
during two growing seasons. Precipitation was 107% and 63%
of the long-term mean (283 mm) in 1989 and 1990,
respectively, which presented an opportunity...
Ranchers and resource managers have become concerned about the
role and spread of Cardaria draba (L.) Desv. (whitetop) in the sagebrush
steppe of Northeastern Oregon. This area is an important natural resource
for livestock production and big game winter range.
An area near Keating, Oregon was selected to study the...
The vegetation response of spring and fall prescribed fires in basin big sagebrush (Artemisia tridentata subsp. tridentata Nutt.)/Idaho fescue (Festuca idahoensis Elmer)--bluebunch wheatgrass (Agropyron spicatum Pursh. (Scribn. & Smith)) communities was measured at the John Day Fossil Beds National Monument in eastern Oregon. Objectives of the study were to quantify...
This research employed multivariate analytical techniques to
statistically examine the relationship between individual soillandscape
units (SLUs) in Southeastern Oregon and their associated
sagebrush communities. The objective was to determine if soil properties
between SLUs differed, describe the variation, and verify that
these differences were reflected in the taxonomic class of...
Four studies were conducted. First, mountain big sagebrush communities were burned at Lava Beds National Monument, California, and The Crooked River National Grassland, Oregon. In two years at Lava Beds, basal cover of Idaho fescue in one community and Thur- ber's needlegrass in one of three communities did not recover....
"Crested wheatgrass, beardless wheatgrass, and big bluegrass were
seeded as overstory grasses. Streambank wheatgrass, canby bluegrass,
bulbous bluegrass, and Ladak alfalfa were seeded as companion species.
Pure and mixed stands were seeded on sagebrush-bunchgrass
range in eastern Oregon to compare yield and competitiveness. The
grasses were planted in 1956, 1957,...