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Sage-grouse (Centrocercus spp.) populations have declined dramatically throughout the western United States since the 1960s. Increased gas and oil development during this time has potentially contributed to the declines. I investigated impacts of development of natural gas fields on greater sage- grouse (C. urophasianus) breeding behavior, seasonal habitat selection, and population growth in the upper Green River Basin of western Wyoming. Greater sage-grouse in western Wyoming appeared to be excluded from attending leks situated within or near the development boundaries of natural gas fields. Declines in the number of displaying males were positively correlated with decreased distance from leks to gas-field-related...
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The focus of this report is the endangered and threatened fishes of the Upper Colorado River system, but a full appreciation would not be possible without an adequate knowledge of the ecosystems in which they live. The six major sections of the report are: abiotic components, biological components, species description, river basin descriptions, major factors inducing environmental change, and urgent needs and recommended research priorities in regard to the upper Colorado River System. (Deal-EIS)
Categories: Publication; Types: Citation, Thesis Citation
A written survey of 200 Moab residents was used to measure residents' attitudes toward tourism. Three regression models were developed using variables identified in the tourism literature to measure the relative importance of interpersonal contacts with tourists, negative impacts to outdoor-recreation experiences, and community experience in predicting attitudes toward tourism. Interpersonal contacts and recreation impacts both had fairly high predictive capabilities. It was concluded that interactions between recreation visitors/tourists and local residents should be a focus of further research. Data from the Moab resident survey were also used in conjunction with a survey of mountain bikers visiting or living...
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This dissertation has three main parts. The first was a study of effects of nitrogen availability and the exotic weed Bromus tectorum L. on the density of vesicular-arbuscular mycorrhizae (VAM) fungi in disturbed land in Colorado. Field and laboratory studies were designed to measure the change in density of VAM fungi in response to available N levels and plant species present. Three nitrogen treatments were established:1) added nitrogen (N+); 2) control (no added nitrogen, C); and 3) sucrose added to reduce nitrogen availability (N-). Two common grasses, the exotic annual weed B. tectorum and a native perennial Agropyron smithii Rydb., were examined in this study. Soil samples beneath each species were taken from...
Categories: Publication; Types: Citation, Thesis Citation
Ecological investigation and experiments were conducted in the big sagebrush (Artemisia tridentata) hybrid zones in Utah to test the two hybrid zone models. The dynamic equilibrium model posits universal hybrid unfitness resulting from the disruption of coadapted gene complexes, i.e., selection is solely caused by intrinsic genetic interactions and hence is endogenous. This model predicts that hybrid zones should occur at areas of low population densities. Alternatively, the bounded hybrid superiority model assumes that the interplay of genotype and environment determines fitness and the positions and stability of hybrid zones. In this model, selection is ecological and hence is exogenous. This model predicts that...
Categories: Publication; Types: Citation, Thesis Citation
The semi-arid grassland communities within Indian Creek and Canyonlands National Park, Utah, have evolved in the absence of large herds of ungulate grazers. However, since the early 1800’s this region was actively grazed by cattle which lead to the reduction of cryptobiotic soil cover (a symbiotic grouping of keystone species) as well as changes in plant community composition. Starting in 1970, Canyonlands National Park was expanded and cattle grazing was removed from parts of Canyonlands, including the Indian Creek corridor. This removal of cattle afforded the opportunity to examine the interaction of cryptobiotic soil cover and cattle grazing activity on the composition of the grassland vegetation communities....
Categories: Publication; Types: Citation, Thesis Citation
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Small mammal populations were live-trapped at two campsites and two control areas along the Colorado River in Canyonlands National Park, Utah, to determine the effects of camping impact on small mammal numbers. Data were collected from August 20 to September 10, 1976, and from April 11 to September 10, 1977. Captures of the canyon mouse (Peromyscus crinitis), least chipmunk (Eutamias minimus), antelope ground squirrel (Ammospermophilus leucurus), white-throated wood rat (Neotoma albigula) and rock squirrel (Spermophilus variegatus) populations were numerous enough to permit statistical comparison. At the Brown Betty campsite, small mammal populations, with the exception of rock squirrels, increased with campsite...
Population genetic structure of boreal toad (Bufo boreas boreas) in Utah: A basis for defining units of conservation, credited to Hogrefe, Todd C, published in 2001.
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A grassland restoration project was conducted in Canyonlands National Park on an area recently disturbed due to construction. Two native grasses (Oryzopsis hymenoides and Stipa comata) were seeded with 18 different soil treatments. Stipa density and relative mycorrhizal colonization were measured. None of the soil treatments resulted in significantly greater Stipa density than the control treatment of seeding only plus water. There was very little correlation between Stipa density and mycorrhizal colonization based on the treatments (r2= 0.011 p = 0.05). Three treatments produced 3 to 5 times the VAN colonization as the control including spring cryptobiotic soil crusts, with and without sugar, and fall soil crusts...
Bromus tectorum impacts soil carbon storage in semiarid grasslands of Canyonlands National Park, credited to Englund, Sylvia Ruth, published in 2004.
The deposition of aeolian (windblown) dust is a global phenomenon with significant implications for terrestrial ecosystems. In particular, the geochemical flux of dust can be an important factor for biogeochemical cycling in soils and, in some settings, may influence ecosystem productivity and chemical weathering. To quantify the role of exogenous dust in soils, the flux and composition of dust must be compared with local soil forming factors. In general, the magnitude, particle size, and geochemical composition of dust vary regionally and are primarily dependent on the distance from dust source area. Each winter/spring the San Juan Mountains (SJM) receive a substantial flux of exogenous dust, which most likely...
Categories: Publication; Types: Citation, Thesis Citation
Soil organic matter content in the cold desert of the Canyonlands physiographic section of the Colorado Plateau is low and poorly studied. In this environment there is a strong temporal offset between soil temperature and moisture. Because of this temporal offset between soil temperature and moisture, turnover of soil organic matter is regulated on the basis of thresholds. When soil moisture is above 9.5% and temperature is below 15.7�C, turnover of soil organic matter is high but when soil temperature is above 15.7�C moisture is limiting and turnover is slow. This threshold based regulation of soil organic matter turnover is different from what occurs in other ecosystems where soil temperature and moisture continuously...
Categories: Publication; Types: Citation, Thesis Citation
In recent years, two populations of the rare Relict Leopard Frog (Rana onca) have gone extinct. These population extinctions occurred concomitantly with the encroachment of native emergent vegetation into pools in which frogs were usually observed. In order to determine if adult Rana onca prefer more vegetatively open habitats, a radio-telemetry study was conducted. A total of 809 radio telemetry observations were made on 34 frogs from April 2 through December 7, 2004. Binary Logistic Regression was used with both macrohabitat and microhabitat data to compare habitat characteristics between low-use and high-use segments of the spring. A more traditional multiple analysis of variance (MANOVA) approach was also used...
Categories: Publication; Types: Citation, Thesis Citation
Sea Breeze Variations in Florida, credited to Mueller, L., published in 2011.
Categories: Publication; Types: Citation, Thesis Citation
I studied desert bighorn sheep (Ovis canadensis, nelsoni) behavior and habitat use in response to boating activities during 1985. The percent of total observed time in attention behavior before the boating season, during the boating season, and while riverboats were < 0.8 km from bighorn sheep groups was 1, 1.4, and 12.2, respectively. Estimated energy expenditure did not significantly differ for high riverboat pressures (p > 0.2) or seasonal comparisons (p > 0.1). Habitat use significantly differed for proximity to the river, which was probably related to the summer use of the river for drinking. Moderate, minor, and no responses to passing riverboats were observed 3, 39, s and 58%, respectively. Responses to riverboats...
Water is essential to life because its unique properties facilitate a vast number of biochemical processes that enable all organisms to exist. Maintenance of proper water concentration in the body is thus a vital activity. Colonization of terrestrial habitats placed organisms in desiccating environments that emphasized problems of water balance. The procurement and economical use of water has since been a central organizing theme in biology and has shaped the morphology, physiology, behavior, and spatial distribution of organisms. In hot, and environments like North American deserts, organisms are faced with especially challenging abiotic conditions characterized by variable and often extreme temperatures, intense...
Alluvial architecture of the Upper Triassic Chinle Formation, Cane Springs Anticline, Canyonlands, Utah, credited to Hazel Jr, Joseph E, published in 1991. Published by Northern Arizona University, in 1991.
Density-dependence is considered one of the most important regulators of population growth, and it has been documented across a wide variety of species. Typically, population growth rate and components thereof decline with increasing density (i.e., negative density-dependence); however, in species that exhibit high population densities and social behavior, positive density-dependence (i.e., Allee effect) may occur at low density. June sucker, a federally endangered lake sucker endemic to Utah Lake, Utah, v USA, occurred historically at high density, and it exhibits coordinated feeding behavior. These characteristics indicate a potential for the existence of an Allee effect at current low population densities. To...
Categories: Publication; Types: Citation, Thesis Citation
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Infrequent seeps and springs along xeric canyon walls of the Colorado Plateau support hydrophytic habitats called hanging gardens. Vascular plant community heterogeneity, species-area relationship, species-occurrence pattern, and level of endemism were determined for 84 hanging gardens. Vascular plant species importance was used to develop hanging-garden vegetation types. Bee (Superfamily Apoidea) and small-mammal communities also were sampled for species richness, relative abundance, and species-occurrence patterns (the last, bees only). Hanging gardens in Arches, Canyonlands, and Zion National Parks, Dinosaur National Monument, and Glen Canyon National Recreation Area were equally large and species-rich compared...
Mathematical programming models of agricultural production in the Colorado River Upper Basin were integrated with a hydrology model of the Colorado River to assess the impacts of transferring water from irrigation uses in the Upper Basin to urban users in the Lower Basin. One strategy involved a long-term lease of irrigation water on an annual basis. The other assessed a lease-option strategy by the Lower Basin to take Upper Basin water only when needed. The economic impacts measured were changes in regional income, agriculturally generated income, crop production, land use, and input expenditures. Environmental impacts considered were changes in river salinity levels and increased hydropower production resulting...
Categories: Publication; Types: Citation, Thesis Citation


map background search result map search result map An evaluation of habitat conditions and species composition above, in, and below the Atomizer Falls Complex of the Little Colorado River Revegetation of disturbed semiarid grassland in Canyonlands National Park Campsite impacts on small mammals of the Colorado River, Canyonlands National Park, Utah Relationships Among Nitrogen Availability, Vesicular-Arbuscular Mycorrhizae, and Bromus tectorum in Disturbed Rangeland Sites in Colorado Biogeography of hanging gardens on the Colorado Plateau Revegetation of disturbed semiarid grassland in Canyonlands National Park Campsite impacts on small mammals of the Colorado River, Canyonlands National Park, Utah Relationships Among Nitrogen Availability, Vesicular-Arbuscular Mycorrhizae, and Bromus tectorum in Disturbed Rangeland Sites in Colorado An evaluation of habitat conditions and species composition above, in, and below the Atomizer Falls Complex of the Little Colorado River Biogeography of hanging gardens on the Colorado Plateau