Ecology and Evolutionary Biology Commons^™

Terpenes And Carbohydrate Source Influence Rumen Fermentation, Digestibility, Intake, And Preference In Sheep, J. J. Villalba, F. D. Provenza, K. C. Olson

Green Canyon Environmental Research Area, Logan Utah

We hypothesized that toxins and nutrients in foods interact to influence foraging behavior by herbivores. Based on this hypothesis we predicted that 1) terpenes in big sagebrush (Artemisia tridentata) influence intake and preference in sheep for diets varying in sources of nonstructural (barley grain) and structural (sugar beet pulp) carbohydrates, and 2) these effects are due to the differential effects of terpenes on fermentation products and apparent digestibility of each class of carbohydrates. Lambs were fed 2 isoenergetic and isonitrogenous diets with varying proportions of the same ingredients (beet pulp- and barley grain-based diet) or offered a choice between the …

Good Practices For Sharing Ecological Models, Karin M. Kettenring, Barbara T. Martinez, Anthony M. Starfield, Wayne M. Getz

Watershed Sciences Faculty Publications

As the fields of ecology and conservation biology increasingly rely on models to address pertinent questions, there has been greater sharing of models among scientists. However, many models lack comprehensive documentation, especially in a format that is easy to use and to understand. Also, modelers lack a framework they can use when evaluating a model for its potential use. Here we outline how ecologists and conservation biologists can begin to establish a culture of good practice for model sharing. We offer suggestions on how model developers, model users, user communities, and journal editors can contribute to the appropriate sharing of …

Alternative Futures For The Bear River Watershed, Richard E. Toth

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The Bear River Watershed (BRW) is located in northeastern Utah, southeastern Idaho, and southwestern Wyoming. Over the three states the watershed encompasses an area of 7,500 square miles (4,800,000 acres). The Bear River 's headwaters begin at close to 13,000 feet in the High Uintas Wilderness Area of northeastern Utah. The course of the river follows a horseshoe pattern flowing north through Wyoming, Utah, and Idaho before bending south at Soda Springs. The river then meanders through the Gem and Cache Valleys before reaching its delta at the Great Salt Lake at an elevation of 4,211 feet.

Effects Of Fire Disturbance On Terrestrial Salamanders In Mixed-Coniferous Forests Of The Klamath/Siskiyou Region Of The Pacific Northwest, Donald J. Major

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An effective examination of fire disturbance on floral and faunal components requires research that integrates knowledge from multiple disciplines to understand the pattern and process controls affecting organisms in a complex system. However, current fire effects research typically focuses on the pattern response of organisms or their habitats with little integration of the dynamic fire process that created the pattern. This dissertation integrates an analysis of the processes of fire disturbance with terrestrial salamander ecology in a fire-dependent forest ecosystem, Klamath Province, California, USA.

In Chapter 1, I begin with a comprehensive review of disturbance ecology, focusing primarily on fire …

Examination Of The Ecological Differences Between Two Closely Related Endemic Whitefish In Relation To Growth Conditions And Predation Risk, Benjamen M. Kennedy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Benthic Bear Lake whitefish (Prosopium abyssicola) and Bonneville whitefish (P. spilontus) are closely related, yet the extent of ecological separation remains poorly understood. We described their spring and summer distribution and diet in Bear Lake and examined how these were related to environmental growth conditions, and predation risk. In spring and summer, Bonneville whitefish dominated shallower depths (5-30 m), whereas Bear Lake whitefish dominated deeper depths (45-55 m). At intermediate depths (35-40 m), low numbers of both species occurred. Bonneville whitefish ate mostly Chironomidae, whereas Bear Lake whitefish ate mostly Ostracoda. Habitats occupied by Bonneville whitefish …

Cattle Utilization Of Forage Kochia (Kochia Prostrata) And Its Relation To Forage Quality And Plant Morphological Characteristics, Burke W. Davenport

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several experimental lines of forage kochia [Kochia prostrata (L. Shrad.)] have potential to provide taller forage on fall and winter rangelands than the only released variety of forage kochia, Immigrant. This study was conducted to determine differences in cattle utilization among experimental lines of forage kochia and relate them to forage quality and morphological attributes. The utilization of forage kochia was also compared to 'Ladak ' alfalfa [Medicago saliva (L.)] and two entries of winterfat [Krashnennikovia species (Guldenstaedt)]. Cattle utilization was determined by calculating a biomass consumed value and a percent biomass consumed value. Dry weights for …

Landscape Assessment For The Buckskin Mountain Area, Wildlife Habitat Improvement, Bureau Of Land Management

All U.S. Government Documents (Utah Regional Depository)

No abstract provided.

Restoration Of Aspen Woodland Invaded By Western Juniper: Applications Of Partial Cutting And Prescribed Fire, Jonathon D. Bates, Richard F. Miller

Aspen Bibliography

Western juniper (Juniperus occidentalis spp. occidentalis) woodlands are rapidly replacing quaking aspen (Populus tremuloides) stands throughout the northern Great Basin. Aspen stands provide important habitat for many wildlife species and contain a high diversity of understory shrubs and herbaceous species. We studies two juniper removal treatments to restore aspen woodlands in Kiger Canyon on Steens Mountain, Oregon.

Response Of A Peatland Ecosystem To Stratospheric Ozone Reduction In Tierra Del Fuego, Thomas Matthew Robson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tierra del Fuego, at the southernmost tip of South America, is influenced by ozone depletion. The landscape of southern and western Tierra de! Fuego is dominated by peatlands; they are important locally and in the context of global climate change, because they store large quantities of organic carbon.

To determine the influence of solar ultraviolet-B radiation (UV-B) on a Tierra de! Fuego peatland, we selectively filtered solar UV-Bin ten pairs of plots. Polyfluorine filters were used to create the Near-Ambient-UV-B Treatment (90% solar UV-B), and polyester filters to create the Reduced-UV-B Treatment ( 17% solar UV-B). These filters were first …

Quantifying Losses Of Understory Forage In Aspen Stands On The Dixie And Fishlake National Forests, Barton R. Stam

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The West has lost up to 60% of its historic aspen stands over the last century, probably as a result of the successional tendency of aspen to be replaced by coniferous species in the absence of periodic fires. One of several major impacts of this change is the loss of understory forage as conifer canopy cover increases. I measured understory biomass in aspen stands ranging from 0% to 81 % absolute conifer cover in the canopy and found that understory production declines exponentially as conifers replace aspen. I also did an economic analysis to determine the value of the forage …

Alternative Future Growth Scenarios For Conserving Open Space Along Utah's Wasatch Front: A Case Study For The Mountain Land Association Of Governments, Richard E. Toth

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Over the past 20 years, rapid suburban and second-home development along Utah's Wasatch Front has threatened to irreversibly alter the region 's character and quality of life. This rapid development has raised concern among federal, state, county and community leaders with respect to the protection of surface and subsurface water; public health, safety and welfare; public services and infrastructure, and open space. The major areas being developed include the valley edges and bottom lands, riparian zones, agricultural lands and bench areas. Since most of these areas are under private ownership, they are highly vulnerable to an array of development activities.

Snow Avalanche Disturbance In Intermountain Spruce-Fir Forests And Implications For The Spruce Bark Beetle (Coleoptera: Scolytidae), Elizabeth G. Herbertson

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Spruce beetle outbreaks are the primary biotic disturbance affecting forests in the Intermountain spruce-fir zone. Major snow avalanches can produce large quantities of host material for spruce beetle colonization; however, few studies have examined the influence of avalanche disturbance on outbreak initiation. The purpose of my research was to investigate potential relationships between these two disturbance agents. In the first study, I used dendro-ecological analyses to date major avalanche years on the Wasatch Plateau in south-central Utah, and then determined what climate factors were associated with avalanche occurrence. The results indicated that mean January snowfall was significantly related to the …

Long-Term Environmental Effects Of Conifer Removal To Achieve Aspen Release In Near-Stream Areas Within The Northern Sierras, Kenneth W. Tate, Bobette Jones, Melanie Mcfarland, Tom Rickman, Al Vasquez

Aspen Bibliography

The advanced state of conifer encroachment in aspen stands in the Sierra Nevada and southern Cascades is retarding aspen regeneration, putting an estimated 70 plus percent of stands at immediate risk of extinction with a significant percentage of stands already lost.

Executive Summary The Role Of Ungulate Herbivory And Management On Ecosystem Patterns And Processes: A Problem Analysis, John G. Kie, Martin Vavra

Aspen Bibliography

No abstract provided.

Some Environmental Relationships Of Undergrowth Species In Aspen Communities Of The Intermountain West, W F. Mueggler

Aspen Bibliography

This analysis results from an opportunity to explore plant-environmental relationships from data collected for a different purpose. Origin of the data is a study designed to develop an aspen community-type classification for southern Idaho, western Wyoming, Utah, and Nevada which resulted in the publication "Aspen Community Types of the Intermountain Region" GTR INT-250 by W.F. Mueggler (1988).

Breeding Bird Communities Of Major Mainland Rivers Of Southeastern Alaska, Jim A. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Because of the scarcity of information for bird communities at the major mainland rivers of southeastern Alaska, the main objective of this study was to provide baseline information including distribution, status, and habitat associations of breeding birds.

I conducted a meta-analysis of all known reports (including the current study) conducted at major mainland rivers during the breeding season. I described bird species composition, distribution, abundance estimates, status, habitat associations, and guild membership for all birds recorded at 11 major mainland rivers. Based on incidental observations, 170 species were recorded by all studies. Of these, 134 species were known or suspected …

Habitat Associations Of Rare Species: A Case Study Using Columbia Spotted Frogs (Rana Luteiventris) In Utah, Nathan E. Welch

Biology

Conservation plans benefit from basic ecological information about factors that limit the distribution of focal species. This study illustrates two observational approaches used to investigate the ecology of the Columbia spotted frog (Rana luteiventris), a rare species in Utah. First, hypothesized frog-habitat associations were evaluated by comparing occupied and apparently unoccupied ponds. Data were analyzed using Akaike's Information Criterion to quantify evidence for hypotheses and to select predictive models. Although variable, results suggest frogs are more likely to be found in ponds that do not shrink in size seasonally, maintain a relatively constant seasonal water temperature, and have …

The Invasion Of The Exotic Cladoceran Daphnia Lumholtzi To Willard Bay Utah: Alterations Of The Pelagic Food Web., Olivia Lester

Undergraduate Honors Capstone Projects

Willard Bay, a freshwater impoundment of one of the arms of the Great Salt Lake, is shallow, with a mean volume of 9,900 acres and a maximum summer depth of six meters. This reservoir is highly productive, with a mean secchi depth of 4 meters and chlorophyll a concentrations peaking in summer at 9 micrograms per liter.

Determining The Factors That Control Respiration And Carbon Use Efficiency In Crop Plants, Jonathan M. Frantz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the literature on plant respiration, there are two viewpoints concerning the source of respiratory control: supply (photosynthate availability) or demand (temperature dependent) limitations. While different studies indicate the primary dependency for respiration is either the supply or demand side, the two paradigms cannot both be true. The relative importance of each paradigm may depend on a number of factors including period of time during which respiration is measured, phase of plant development, environmental conditions, and species.

Studies were performed using continuous CO₂ gas-exchange instrumentation to monitor short- and long-term changes in whole canopies of lettuce, tomato, soybean, and …

Simulation Of Wind Dispersal Of Tree Seeds, Tree Colonization, And Growth Of Bottomland Hardwood Reforestation Sites Of The Mississippi Alluvial Valley, Timothy James Nuttle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tree community composition in bottomland hardwood reforestation sites is considerably less diverse than natural bottomland hardwood forests. This study sought to understand the mechanisms behind failure to develop diverse tree communities. First, I developed a mechanistic model of seed dispersal by wind in spatially variable environments. Second, I developed a spatially explicit simulation model of forest dynamics that includes this wind-dispersal model to investigate whether diversity is limited by dispersal or interactions among species and individuals. Finally, I performed model experiments to determine if manipulations of stand structure might help improve conditions for colonization of various species, thus enhancing diversity …

Utah Forest Health Report : A Baseline Assessment 1999 - 2001, Colleen Keyes, Paul Rogers, Leon Lamadeleine, Vick Applegate, Dave Atkins

The Bark Beetles, Fuels, and Fire Bibliography

This report addresses forest health in two ways: by discussion of forest-related issues and by data summaries in several appendices. FHM is a long-term monitoring program and therefore, the data presented in this report must be viewed in that light. This report presents a first-time, or baseline summary. Subsequent reports will address changes over time as plots and other detection surveys are conducted and re-measured.

Good Intentions May Doom Aspen Groves, James R. Fazio

Aspen Bibliography

If there were a Guiness Book of World Records for trees, quaking aspen would be in it - not once but probably several times.

Effects Of Range Size On Species–Area Relationships, Andrew P. Allen, Ethan P. White

Biology Faculty Publications

It has been known for some time that the slope of the species–area relationship increases asymptotically at broad spatial scales when richness is plotted against area on logarithmic axes. At continental to global scales, species–area relationships are determined to a large extent by the abundance and size distribution of species ranges. Here we present an analytical model that explicitly quantifies the effects of range size on species–area relationships. The model shows how range size and plot area interact to control the form of species–area relationships at broad spatial scales. It also demonstrates how changes in spatial scale affect biodiversity patterns …

The Role Of Brown Bears (Ursus Arctos) In Nutrient Transport Into Forests Near A Salmon Stream In Coastal British Columbia, Canada, Arthur Morris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nutrients from spawned salmon contribute to the fertility of rivers and riparian areas. Adjacent forests, even far from rivers, could receive substantial amounts of nitrogen and other nutrients from salmon. Since brown bears feed heavily on spawning salmon, bears probably influence the movement of nutrients from salmon into surrounding forests. Because salmon-derived nitrogen is high in ¹⁵N, increased isotopic enrichment is expected in forest soils and vegetation if this transport is occurring. Based on relative ¹⁵N enrichment of spawning areas, a quantitative estimate of marine-derived nitrogen (MDN) can be obtained using a linear two-source mixing model. To evaluate …

Community-Level Effects Of Clearcutting And Wildfire On Shrews, Grasshoppers, And Ground-Dwelling Beetles, J. Creed Clayton

Biology

Timber harvesting is often proposed as a substitute for stand-replacing wildfire; many feel such a controlled disturbance plays a similar ecological role to the natural disturbance of fire. In order to gain more insight into the soundness of this management approach, ground-dwelling beetles (Coleoptera), grasshoppers, crickets, and allies (Orthoptera), and shrews (Insectivora: Soricidae) were sampled by pitfall trap in recently burned, clearcut, and undisturbed forested plots (controls) near Logan, Utah. Over 200 beetle species from 39 families were included in the study. Nine orthopteran and two shrew species were included as well. Beetle abundance was reduced after burning and clearcutting, …

Coyote Foraging Ecology, Vigilance, And Behavioral Cascades In Response To Gray Wolf Reintroduction In Yellowstone National Park, T. Adam Switalski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vigilance behavior can aid in the detection of predators and may also play a role in observation of conspecifics, in food acquisition, and in the prevention of kleptoparasitism. However, in most occasions, vigilance is most important as an antipredator function. Generally, factors that increase the risk of predation also increase the amount of vigilance. We examined whether the reintroduction of the large predator, the wolf, in Yellowstone National Park (YNP) would influence coyote vigilance and foraging ecology. From December 1997 to July 2000, we collected 1743 h of coyote activity budgets. Coyote home ranges occurred within wolf territories (termed high-use …

Application Of Biophysical Data To An Unsupervised Classification To Map Ecoregional Boundaries In The Desert Southwest, Paxton R. Mcclurg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An unsupervised classification was applied to continuous biophysical variables in an attempt to delineate ecoregional boundaries in the desert southwest. Output was then compared with ecoregions delineated by the Natural Resources Conservation Service (NRCS), the Environmental Protection Agency (EPA), and the Forest Service at the national level. An attempt was made to use the same biophysical variables for input into the unsupervised classification as was emphasized by the various agencies with their ecoregional classifications at the desert level. Major constraints included data availability at such a large study area, data resolution, and data that were continuous. This eliminated categorical data …

Effectiveness Of Earthen Escape Ramps In Reducing Big Game Mortality In Utah, Mary L. Hammer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One-way escape gates and earthen escape ramps are structures used to enable deer to exit the highway right-of-way along fenced roads. I compared the use of one-way escape gates and earthen escape ramps by mule deer on two highways in Utah to determine if deer exhibited a preference for either structure. Results showed that earthen escape ramps were used by mule deer 8-11 times more frequently than one-way gates. Highway mortality data suggest that the installation of the escape ramps likely reduced mortality of mule deer in both study locations, because we could not attribute reductions in mortality to decreased …

Ecology Of Treeline Whitebark Pine (Pinus Albicaulis) Populations In Central Idaho: Successional Status, Recruitment, And Mortality, And A Spring Temperature Reconstruction From Whitebark Pine Tree Rings, Dana Lee Perkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research investigated the successional status of treeline whitebark pine (Pinus albicaulis) populations on 14 stands in central Idaho and used empirical statistical models to determine the principal factors affecting recruitment and mortality. The longest lived whitebark pines from four additional high-elevation sites were used to develop a tree-ring chronology to reconstruct over 1,000 years of average April-May temperature.

The assessment of stand structures using size-frequency distributions generally provides evidence that treeline whitebark pine populations are currently self-sustaining in areas of low to nonexistent incidence of white pine blister rust (Cronartium ribicola). However the presence of …

Energy, Fractal Movement Patterns, And Scale-Dependent Habitat Relationships Of Urban And Rural Mule Deer, Mark F. Mcclure

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied the behaviors, movement dynamics, habitat relationships, and population characteristics of Rocky Mountain mule deer (Odocoileus hemionus) using urban and rural winter ranges in Cache Valley, Utah, from January 1994 to February 1998. There were 2 goals to my research endeavors. The first was to assess how and why the behaviors and demographic characteristics of urban deer differed from those of rural deer. The second was to assess the scale-dependent responses to habitat and the scale-dependent patterns of habitat use by deer living in each area. To accomplish the first goal, I compared the prevalence of migration, the spatial …