High performance concrete (HPC) provides a long lasting, durable concrete that is typically used in bridge decks due to its low permeability, high abrasion resistance, freeze-thaw resistance and strength. However, this type of concrete is highly susceptible to the deleterious effects of both autogenous and drying shrinkage. Both types of...
Numerous evergreen trees and shrubs contain labdane acids, including isocupressic acid, which can cause
late-term abortions in cattle. Recent research has shown that the bark from western juniper trees can
also cause late-term abortions in cattle. Additionally, ranchers have observed that cattle in western juniper-infested
rangelands tend to have decreased...
An improved understanding of ecohydrologic connections is critical for improving land management decisions in water-scarce regions of the western United States. For this study, conducted in a semiarid (358 mm) rangeland location in central Oregon, we evaluated precipitation-interception-soil moisture dynamics at the plot scale and characterized surface water and groundwater...
The objective of this study was to determine if supplementing linoleic or α-linolenic acids, and timing of supplementation around AI will alter supplemental intake, ADG, and serum progesterone (P4), cholesterol, and triglyceride concentrations in replacement Angus crossbred heifers. In yr 1, 54 heifers, stratified by age, were assigned to: barley...
Quaking aspen (Populus tremuloides) is one of a few iconic trees that symbolize the spirit of the West. Though sparsely distributed throughout Oregon, aspen is an important species, providing a long history of benefits to both people and wildlife. “Quakies,” as many call aspen, are well liked by ranchers, hunters,...
Full Text:
, management of medusahead
and western juniper, and fire ecology.
TimDeboodt started working for the
Quaking aspen (Populus tremuloides) is one of a few iconic trees that symbolize the spirit of the West. Though sparsely distributed throughout Oregon, aspen is an important species, providing a long history of benefits to both people and wildlife. “Quakies,” as many call aspen, are well liked by ranchers, hunters,...
Full Text:
TimDeboodt
Aspen stands throughout Oregon are in an
ongoing state of decline (Cobb and Vavra 2003
Western juniper (Juniperus occidentalis) encroachment has been associated with negative ecological and hydrological consequences including reductions in herbaceous production and diversity, deterioration for wildlife habitat, and higher erosion and runoff potentials. As a result, western juniper removal is a common and accepted rangeland management practice. Although studies evaluating the ecological...
Water scarcity in semiarid environments provides a model system to evaluate the role of mesic resources in structuring the distribution and abundance of wildlife. We used remote sensing and point process analyses to evaluate spatio–temporal variability in limited mesic resources in relation to greater sage-grouse (Centrocercus urophasianus) distributions in Oregon,...
The hydrologic function of a landscape is an important concept for understanding the presence, movement and availability of water. The Camp Creek Paired Watershed Study (CCPWS) site in Central Oregon has been utilized to investigate the impacts of western juniper on watershed hydrologic function since 1993. The research presented here...
An improved understanding of the ecohydrologic relationships in semiarid rangelands is imperative for the development of effective rehabilitation and land management practices. This thesis addresses the ecohydrologic relationships of two significant issues concerning semiarid rangeland ecosystems: western juniper encroachment and increasing stream temperatures.
This thesis is divided into two chapters;...