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...
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...
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Chapter 3: Moth Abundance and Diversity in a Mixed Sagebrush-Steppe Community
in Central Oregon
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...
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
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...
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...
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...
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,...
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...