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...
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...
Restoration of invaded aridlands is required to reduce the exorbitant ecological and monetary losses related to noxious weeds. An understanding of how reduced and increased levels of soil N and P influence interference between medusahead and squirreltail is imperative to understanding how squirreltail may be used in restoration of medusahead...
Managing rangelands with livestock grazing is a tool that can be applied to obtain vegetation management objectives. Animals utilize available resources, which vary in quantity and quality, across the landscape. Their movements are adjusted to the spatial and temporal heterogeneity of resource distribution. Controlling livestock distribution is fundamental to economically...
On piñon-juniper encroached sites that lack the understory fuels to carry a prescribed fire, treatment options are limited to mechanical methods. Cutting with chainsaws and leaving the trees on site has been the primary treatment method for such sites, however this method creates a potential fire hazard, particularly in the...
Greater Sage-grouse (Centrocercus urophasianus) habitat research has historically focused on fine-scale (0.007 - 0.032 ha) vegetation structure and composition immediately surrounding sites selected by birds. However, little work has evaluated vegetation attributes important for Greater Sage-grouse at a landscape-scale or identified landscape attributes that influence habitat use patterns. Habitat use...
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...
The goal of this dissertation is to examine the effectiveness of high intensity-short duration goat browsing for the control of Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix), two widespread noxious weeds in the Pacific Northwest.
The effects of goat browsing on Himalayan blackberry vigor, as quantified by densities...
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...
Krascheninnikovia lanata (winterfat) is a valuable forage species with an
average of 10% crude protein during winter when there are few nutritious options for
livestock and wildlife. However, excessive grazing throughout the west has negatively
impacted survival of winterfat stands. We hypothesized that four years rest from
dormant season livestock...