Ecology and Evolutionary Biology Commons^™

Carnivore Competition And Resource Use In The Serengeti Ecosystem Of Tanzania, George Walter Frame

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coexisting ungulate-eating carnivores--lion, spotted hyena, cheetah, leopard, African wild dog, black-backed jackal, common jackal, and six species of vulture--are examined in East Africa's Serengeti ecosystem. Niche similarities year-round, by season, and by location are described using food, habitat, time of hunting, and other variables. Intraspecific niches of cheetah sex, age, and social groups show that male coalitions differ most from the others in hunting behavior and habitat use. Tests using the carnivore data failed to support hypotheses about niche breadth variation, niche overlap variation, range of food items, and niche inclusion. Densities of the five largest Carnivora in the 35,500 …

The Redevelopment Of Plant Community Diversity On A Surface Coal Mine In Southwestern Wyoming, Thomas Joseph Hatton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study was initiated in 1981 to investigate the redevelopment of plant communities on a recontoured, surface-mined site in southwestern Wyoming. The landscape pattern of vegetation was compared with topographic position, the initial topsoil pattern, and cultural practices including shrub planting density, shrub planting pattern and topsoil treatments for the years 1982-1985. In addition, differences in vascular plant species diversity within these various factors and treatments were determined, along with the trend in intracommunity (alpha), intercommunity (beta) and landscape (gamma) diversity for the entire study area.

The influence of site factors and tested cultural practices on the differentiation of the …

A Market Analysis For Adult Outdoor Education In Five Western States, Karla Joy Vanderzanden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Organizations that offer Outdoor Education programs for adults are concerned with how to best attract people to their programs. Effective program design begins with a clear understanding of the people to be served. A marketing orientation--meeting the needs of participants--has begun to pervade non-profit management; specific information on the adult market for Outdoor Education remains limited. The purpose of this study was to identify and characterize segments based upon the benefits people seek from such an experience. Secondly, this analysis describes current programs 1n a five state region and identifies discrepancies between available and needed services.

A mail survey of …

Effect Of Short Duration Grazing On Soil Moisture Depletion And Plant Water Status In A Crested Wheatgrass Pasture, Jon M. Wraith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A short duration grazing system was utilized to determine the effects of intensive periodic defoliation during spring on soil moisture depletion patterns and plant water status in a crested wheatgrass (Agropyron cristatum and A. desertorum) pasture in central Utah. Exclosures were constructed to compare grazed and ungrazed responses. Soil moisture was monitored to a depth of 193 cm at one to two week intervals from mid-April to late-September using a neutron moisture gauge. Predawn and midday leaf water potentials were estimated using a pressure chamber technique. The two paddocks included in the study were grazed three times between …

Animal Nutritional Response To Sward Structure Under Short Duration Grazing Management, Kenneth C. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A ten-paddock short duration grazing cell was stocked with yearling heifers at a stocking rate of 0.7 ha per animal unit month and a stocking density of 0.14 ha per animal unit. A continuously-season- long-grazed (CSLG) pasture was used as a control. It was stocked at the same stocking rate, but at a stocking density of 1.4 ha per animal unit. Grazing periods in SDG paddocks were two or three days. Dietary quality was assessed by crude protein · content and in vitro digestibility of esophageal fistula estrusa samples. Three variables of ingestive behavior were measured, including ingestion rate, biting …

Seasonal Feeding Behavior And Forage Selection By Goats In Cleared And Thinned Deciduous Woodlands In Northeast Brazil, Roberto Cesar Magalhaes Mesquita

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The seasonal feeding behavior, forage preferences and body weight responses of goats were studied under three densities of woodland (called caatinga), and under three stocking rates. The experiment was located in the semi-arid tropics of northeastern Brazil at 3 42' South latitude, and 40 21' West longitude at an elevation of 75 meters. Mean annual precipitation of the area is 832 mm.

Removing the shrubs and trees increased yields of herbaceous only on partially-cleared sites. Goats gained body weight (kg BW/ha) during the wet season, with the cleared treatment showing the best body weight response per unit of land. However …

Growth And Water Relations Of Mountain Big Sagebrush On Reclaimed Mine Soils In Southwestern Wyoming, Alan T. Carpenter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mined-land reclamation practices in shrub-steppe ecosystems can be augmented by planting seedlings of locally dominant shrubs, e.g., mountain big sagebrush. Dispersion pattern could affect sagebrush performance by influencing amounts of windborne snow, soil and litter which accumulate around shrubs and by influencing water withdrawal by roots. Mountain big sagebrush seedlings were planted in plots on a reclaimed coal strip mine in two dispersion patterns: singly and in clumps of four at the same overall density.

Performance of mountain big sagebrush was monitored during two growing seasons. Measures included plant survival, end-of-growing season aboveground biomass, leaf water potential components, soil water …

Behavioral Response Of Desert Bighorn Sheep To Human Harassment: A Comparison Of Disturbed And Undisturbed Populations, Michael M. King

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Desert bighorn sheep (Ovis canadensis nelsoni) response to human disturbance was evaluated in southeastern Utah from 1981-1983. Bighorn response was compared between the Red Canyon area, an area with relatively high levels of human disturbance, and the White Canyon area, an area with relatively low levels of human disturbance. Bighorn were deliberately harassed by vehicles and hikers and immediate response and distance fled were recorded. When bighorn remained in the presence of the harassing stimuli, actual time spent in and proportion of animals engaged in various behaviors were recorded to determine group wariness and activity budgets under harassed …

Temporal And Spatial Partitioning Of The Soil Water Resource Between Two Agropyron Bunchgrasses And Artemisia Tridentata, Halldor Thorgeirsson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dynamics of soil water use by two cool-season Agropyron bunchgrasses during the warm season depletion of soil water reserves were monitored for two years in experimental plots in the field. Agropyron desertorum, an introduced, competitive species from Eurasia, extracted more water from the deeper ( > 50 cm) soil layers than the native, less competitive Agropyron spicatum. Agropyron desertorum both extracts this water earlier and to lower soil water potentials than Agropyron spicatum. From the water extraction dynamics of the grasses in monocultures and in their two-way (50:50) mixtures with a shrub they commonly co-occur with, Artemisia tridentata …

The Acarau Valley In Northeast Brazil: Vegetation, Soils And Land Use., Joao Stacishin De Queiroz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to describe and characterize the principal kinds of land in the mid-portion of the Acarau Valley, Ceara State, Northeast Brazil. The specific aims were: (1) to develop a specific-purpose soil classification; (2) to investigate vegetation-environment relationships; (3) to develop hypotheses about short-term vegetation dynamics; and (4) to evaluate the usefulness of computer processed multispectral-scanner (MSS) data for mapping rangeland resources in Northeast Brazil.

Fifty-one soil profiles were described and ocular estimates of vegetation cover by species were made at each subjectively selected site. Two Landsat scenes were used to assess the usefulness of MSS …

Initial Assessment Of The Introduction Of Spottail Shiner (Notropis Hudsonius) And Delta Smelt (Hypomesus Transpacificus) Into Willard Bay Reservoir, Utah., Thomas E. Sommerfeldt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spottail shiner (Notropis hudsonius) and delta smelt (Hypomesus transpacificus) were introduced into Willard Reservoir to improve the forage base for walleye (Stizostedion vitreum vitreum) and black crappie (Pomoxis nigromaculatus). Spottail shiners were stocked in early spring in 1981, 1982, and 1983. Hauling mortality was generally great and an estimated 34,500 live fish were stocked in the 3-year period. Spottail shiner reproduction occurred each year of stocking. Delta smelt were introduced in 1982 with the stocking of 15,000 adult spawning fish. Stocking survival was estimated at 99%. Freshly spawned eggs were also obtained …

Seed Reserves In Stockpiled Topsoil On A Coal Mine Near Kemmerer, Wyoming, Cynthia K. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objectives of this study were to determine how seed reserves varied with depth in topsoil stockpiles and to evaluate the effect of length of time of storage on the number of viable seeds and number of species of seeds.

Soil samples were taken from five topsoil piles representing zero to three years of storage on the Elkol-Sorenson mine near Kemmerer in southwestern Wyoming. Seeds were extracted using flotation/separation methods and were tested for viability using 2,3,5-triphenyl tetrazolium chloride solution. Data were analyzed using nonparametric statistical tests.

Overall density of seeds in topsoil piles was low. No relationship was found …

Effects Of Clearcutting On Forage Production, Quality And Decomposition In The Caatinga Woodland Of Northeast Brazil: Implications To Goat And Sheep Nutrition, Robert D. Kirmse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Clearing of trees from the so-called caatinga woodland that characterizes the vegetation of the semi-arid region of northeast Brazil offers possibilities for increasing forage production. This research analyzed the first-year effects of clearing caatinga on dry season forage for goats and sheep. In addition, factors affecting litter decomposition on cleared and uncleared caatinga were assessed to evaluate the viability of deferring grazing of forages during the wet season for use later in the dry season.

Removing the trees resulted in a sixfold increase in production of herbaceous vegetation, however, 88 percent of the increased yield on the cleared areas was …

Plant Gas Exchange Of Two Bunchgrasses In Relation To Herbivory Tolerance, Robert S. Nowak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The occurrence of compensatory photosynthesis was examined in the field during the spring for all foliage elements on two Agropyron bunchgrass species that differ in their evolutionary history of grazing pressure. Compensatory photosynthesis did occur in many individual foliage elements during at least part of their ontogeny. For both species, compensatory photosynthesis was related primarily to delayed leaf senescence and increased soluble protein concentrations, but not to an improvement in the water status of clipped plants. Photosynthetic water use efficiency and photosynthetic rates per unit soluble protein of foliage on partially defoliated plants were not increased following the clipping treatments. …

Applying The Concept Of Feeding Stations To The Behavior Of Cattle Grazing Variable Amounts Of Available Forage, Enrique R. Flores

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A quantitative description of the foraging process is necessary for effective planning and execution of intensive grazing schemes. Foraging behavior is defined as having two components: feeding and moving. At intervals the foraging animal walks a number of steps searching for food and then pauses to feed at a new position here termed a feeding station. Five behavioral variables were analyzed under this framework: 1) time spent at a feed ing station; 2) number of bites at a feeding station; 3) steps taken between stations; 4) rate of steps; and 5) foraging time. The experimental design consisted of grazing small …

Differential Behavior Of Coyotes With Regard To Home Range Limits, Charles E. Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was conducted to examine coyote behavioral responses to novel stimuli in familiar and unfamiliar environments and the implications of this behavior with regard to specific coyote management and research techniques. A series of pen studies with captive coyotes was undertaken at the U.S. Fish and Wildlife Service's Predator Ecology and Behavior Project research site, Logan, Utah, to observe the range and type of behaviors coyotes showed towards small novel objects and standard scent stations in familiar and unfamiliar 1-ha enclosures. The initial response to these novel stimuli in familiar environments was one of neophobia and caution, whereas in …

Use Of Clearcut Habitats By Black Bears In The Pacific Northwest, Kim R. Barber

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Patterns of vegetation use by black bears (Ursus americanus) on Long Island, Washington were documented using radio-telemetry in 1973-74 and 1980-81. Secondary succession altered the vegetative compostion of clearcut areas through this time, reducing the areas dominated by productive brush species by nearly 50%. Seasonal food habits, consisted primarily of grasses and forbs in spring (den emergence-May) and flowers and fruits of shrub species in summer (June-September) and fall (October-den entrance).

Bears selected for clearcuts (5-21 years of age) over all other vegetation types for feeding but preferred areas dominated by large trees when inactive during both the …

Mule Deer Reproduction And Survival In The Lasal Mountains, Utah, Randall B. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mule deer (Odocoileus hemionus) reproduction and survival on the LaSal Mountains, Utah were studied from 1978-81. Reproductive rates were high, suggesting that summer and fall forage quality was adequate and was not responsible for low recruitment observed in recent years. The combined fetal rate, determined from laparotomies and carcasses, was 1.72 for all females older than 1 year (N = 114). Fetal rates were 1.15 for yearlings (N = 20), 1.80 for prime females (2-7 years, N = 78), and 1.75 for old females (8+ years, N = 16). No evidence of breeding was found among fawns (N …

Brown Trout Perception Of Ultraviolet Radiation And Possible Influence On Distribution, Terrence H. Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Brown trout (Salmo trutta), demonstrated an avoidance response to a range of intensities of artificial ultraviolet radiation in a laboratory setting. UV field measurements were made under a variety of riparian canopies in a mountain river system. UV values at various depth regimes were compared with laboratory response values. Results suggested that ultraviolet light could be a factor in the absence of brown trout in particular habitat types at various times during the daylight hours. Visible light intensity response values were also obtained under the same experimental and field conditions. These data suggested that visible light also could …

The Interaction Of Ultraviolet-B Radiation Stress And Plant Competition In Agricultural Plant Populations, Warren Glenn Gold

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of ultraviolet-B radiation enhancement upon the competitive interactions of two species pairs was studied in the field. Wheat (Triticum aestivum L. 'Bannock') was paired with wild oat (Avena fatua L.) and jointed goatgrass (Aegilops cylindrica Host) to represent competition between species pairs in agricultural situations. Specially modulated ultraviolet lamp systems provided either low ultraviolet-B enhancement (simulation of a 16 % ozone layer reduction based upon the generalized plant action spectrum), high ultraviolet-B enhancement (40 % ozone reduction) or control (ambient solar ultraviolet-B) irradiance.

Ultraviolet-B radiation enhancement significantly altered the competitive interactions of the species pairs. …

Establishment Of Tall Wheatgrass [Agropyron Elongatum (Host) Beav. 'Jose'] And Basin Wildrye (Elymus Cinereus Scribn. & Merr. 'Magnar') In Relation To Soil Water And Salinity, Bruce A. Roundy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The potential of basin wildrye (Elymus cinereus Scribn. & Merr. 'Magnar') and tall wheatgrass [Agropyron elongatum (Host) Beav. 'Jose '] to establish on saline, arid rangelands in the Great Basin in relation to soil water and salinity was compared in field and laboratory experiments. Tall wheatgrass had higher emergence and establishment on a nonsaline and a saline soil (electrical conductivity of the saturation extract of 7 dS·m^-1) over a range of spring precipitation as simulated by sprinkler irrigation. Basin wildrye will require supplemental irrigation to establish on soils of similar salinity. In the absence of precipitation, …

Efficacy Of Denning In Alleviating Coyote Depredations Upon Domestic Sheep, James A. Till

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bands of domestic sheep lambing on the open range in south central Wyoming were monitored for predator losses prior to and following coyote (Canis latrans) removals. Experimental treatments, including 1) no removal (control), 2) removal of 2 adults and their pups, and 3) removal of pups only, were replicated 15 times each. Number of predation incidents (events) was reduced 98.2% by removing adults and pups. The number of sheep killed was reduced by 98.8%. Removing only litters of pups resulted in a decrease of 87.7% total kills decreased 91.6%. in predation incidents, while Overall, 23 of 30 predation …

Muskrat Population Levels And Vegetation Utilization: A Basis For An Index, Thomas R. Mccabe

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Muskrats (Ondatra zibethicus) are associated with marshlands throughout North America. Their impact on marsh vegetation is well documented. In recent years, research pertaining to marsh ecosystems has emphasized the role of interspersion of marsh vegetation to higher faunal diversity and productivity. Muskrats can provide a natural control of aquatic emergents if managed properly. Experimentation at Fish Springs National Wildlife Refuge, Utah, has attempted to ascertain whether vegetation-utilization index could be used for determining muskrat population levels and to evaluate the impact of muskrats on their primary food resource, Olney's bulrush (Scirpus americanus).

Three known populations of …

Influence Of Photosynthetic Photon Flux Density On Uv-Binduced Photoinhibition In Soybean Leaves: Comparison Of Preconditioning And Concomitant Light Treatments, Charles W. Warner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous studies indicate that the degree of UV-Binduced photosynthetic inhibition may be highly dependent upon the photosynthetic photon flux density (PPFD, total quantum flux in the waveband 400-700 nm) incident on a plant. This study illustrates that Essex soybean leaves (Glycine max) preconditioned under high PPFD suffered less UV-B-induced photoinhibition than when preconditioned under low PPFD. However, sensitivity to UV-B increased when soybean leaves received high-PPFD as a concomitant treatment.

The relative msgnitude of UV-B-induced damage was similar for both light-limited and light-saturated photosynthesis. This probably indicates that UV-B is inhibiting fundamentally different photosynthetic processes.

Soybean leaves preconditioned …

The Influence Of Winter Social Behavior On The Habitat Selection And Reproductive Success Of The Black-Billed Magpie, Kerry P. Reese

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the influence of winter social behavior, particularly dominance relationships, on the subsequent nesting habitat selection and reproductive success of Black-billed Magpies (Pica pica hudsonia) on 2 areas in northern Utah. Hierarchical cluster analysis ordinated the habitats available to breeding birds and Chi-square and Bonferoni-z statistics were used to determine those habitat types the magpies seemed to prefer. Social status was determined by observing color-banded birds engaged in agonistic encounters at winter bait stations. Social dominance was evaluated by % dyads won, not by total % victories. Relationships between winter social status of magpies and their …

Diversity And Production Of Herbaceous Vegetation In A Northern Utah Subalpine Chronosequence, Gary A. Reese

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Successional trends in herbaceous plant production and diversity were studied in an age sequence of sites, i.e. chronosequence, inferred to represent a meadow to aspen to fir to spruce-fir sere. Primary production was observed to decrease in a linear fashion with successional development. Three components of diversity; richness, heterogeneity, and equitability or evenness, each had low early successional values, reaching maximum diversity in mid-succession, and declining to intermediate levels with maturity. The magnitude of these trends varied greatly, depending on the methods used to determine plant dominance. Characteristics of various dominance indices and their applicability to this study were examined. …

Fall Regrowth Of Crested Wheatgrass And Fourwing Saltbush, Noor Mohammad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During 1980-81, studies with crested wheatgrass (Agropyron desertorum) and fourwing saltbush (Atriplex canescens) were conducted in controlled environment growth chambers as well as under field conditions to achieve the following objectives:

1. To determine the effect of nitrogen fertilizer on the water use efficiency.

2. To determine the effects of various temperature, water stress and nitrogen treatments on the productivity, nitrogen content and carbohydrate reserves.

3. To determine the effects of N fertilization on fall and spring regrowth.

Crested wheatgrass and fourwing saltbush plants were maintained in three growth chambers for 60 days under three temperature …

Seasonal Temperature Preference Of Adult Mountain Whitefish, Prosopium Williamsoni, Jean M. Ihnat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Temperatures selected seasonally by adult mountain whitefish were measured in the laboratory in a horizontal gradient. Final preferendum estimates, based on acute (3-hour) preference tests conducted with fish acclimated to 5, 10, and 15 C each season, were 17.7 C (pre-spawning), 11.9 C (post-spawning), 9.9 C (winter), and 16.3 C (spring). Seasonal influence on temperature selection was evident on the basis of differences in final preferenda, covariance analysis of responses of laboratory-acclimated fish, and temperature selection by fish held at ambient river temperatures. Post-spawning and winter groups selected lower temperatures than did pre-spawning and spring groups. Pre-spawning fish selected temperatures …

Higher Plant Acclimation To Solar Ultraviolet-B Radiation, Ronald Robberecht

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant acclimation to natural and intensified solar UV-B irradiance was investigated in three species, Oenothera stricta Ledeb., Rumex obtusifolius L., and R. patientia L. The objectives of this study were to determine: (1) the relationship between plant sensitivity and epidermal UV attenuation, (2) the effect of phenotypic changes in the leaf epidermis, resulting from UV-B exposure, on plant sensitivity to UV radiation, and (3) the plasticity of these changes in the epidermis leading to plant acclimation to UVB radiation.

Epidermal UV transmittance was found to differ in magnitude and spectral distribution among the three species examined in this study. Epidermal …

Some Morphological And Chemical Responses Of Blackbrush (Coleogyne Ramosissima) To Goat Browsing: Influences On Dietary Blackbrush Selection By Goats And Cattle, Frederick D. Provenza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Domestic goats were used to modify the growth form of blackbrush, a spinescent shrub occurring in nearly monospecific stands on several million hectares of rangeland in the southwestern United States. The objective of this research was to evaluate goat browsing as a means of improving these rangelands for cattle. Winter goat browsing stimulated spring twig growth from basal and axillary buds which resulted in increased production.

Twig production by heavily browsed plants (>95 percent removal of current season's twigs) was a function of precipitation, soil depth, branch location on the plant, and period of rest after browsing. As precipitation …