Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Utah State University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 91 - 120 of 413

Full-Text Articles in Entire DC Network

Why Do They Do That? Understanding Factors Influencing Visitor Spatial Behavior In Parks And Protected Areas, Abigail M. Sisneros-Kidd Aug 2018

Why Do They Do That? Understanding Factors Influencing Visitor Spatial Behavior In Parks And Protected Areas, Abigail M. Sisneros-Kidd

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Visitors to parks and protected areas within the United States and worldwide often visit these areas with a particular destination in mind, such as seeing Old Faithful erupt in Yellowstone National Park or standing on the rim of the Grand Canyon in Grand Canyon National Park. These visitor use destinations, and the pathways leading to them, such as trails and roadways, see high levels of use, and as a result, impacts to soil, vegetation, air, water, soundscapes, and night skies that result from this use. The field of recreation ecology studies these impacts to park and protected area resources resulting …

Go to article

On The Relationship Between Phylogenetic Diversity And Trait Diversity, Caroline M. Tucker, T. Jonathan Davies, Marc W. Cadotte, William D. Pearse May 2018

On The Relationship Between Phylogenetic Diversity And Trait Diversity, Caroline M. Tucker, T. Jonathan Davies, Marc W. Cadotte, William D. Pearse

Biology Faculty Publications

Niche differences are key to understanding the distribution and structure of biodiversity. To examine niche differences, we must first characterize how species occupy niche space, and two approaches are commonly used in the ecological literature. The first uses species traits to estimate multivariate trait space (so‐called functional trait diversity, FD); the second quantifies the amount of time or evolutionary history captured by a group of species (phylogenetic diversity, PD). It is often—but controversially—assumed that these putative measures of niche space are at a minimum correlated and perhaps redundant, since more evolutionary time allows for greater accumulation of trait changes. This …

Go to article

Maternal Vitamin D Deficiency And Early Childhood Health Outcomes Including Autism Development, Kelsey L. Girardelli May 2018

Maternal Vitamin D Deficiency And Early Childhood Health Outcomes Including Autism Development, Kelsey L. Girardelli

Undergraduate Honors Capstone Projects

Many studies have shown that vitamin D deficiency during pregnancy is associated with a variety of adverse maternal and pediatric outcomes. Disease outcomes that have been observed in pregnant women who are vitamin D deficient include increased risk of C-section, preeclampsia, bacterial vaginosis, and gestational diabetes. In children born to deficient mothers, increased rates of childhood asthma, type 1 diabetes, low birthweight, and autism spectrum disorder (ASD) have been observed. Although there is much evidence to support these correlations, much is yet to be understood regarding the etiology of these outcomes. This paper specifically examines the relationships between risk factors …

Go to article

Monitoring Of Dung Beetle (Scarabaeidae And Geotrupidae) Activity Along Maryland's Coastal Plain, Patrick Simons, Michael Molina, Mallory A. Hagadorn, Dana L. Price Mar 2018

Monitoring Of Dung Beetle (Scarabaeidae And Geotrupidae) Activity Along Maryland's Coastal Plain, Patrick Simons, Michael Molina, Mallory A. Hagadorn, Dana L. Price

Biology Faculty Publications

Our understanding of how human activities impact insect communities is limited. Dung beetles, well known for the ecosystem services they provide, are faced with many conservation threats, particularly from deforestation and agriculture. Here we used 200-m transects and human-dung—baited pitfall traps to examine dung beetle populations in 7 forests of Maryland's Coastal Plain. We set traps once a month, from May 2014 to April 2015, to determine species presence, abundance, range, and seasonality. We collected 6463 individuals representing 22 species; Janes Island State Park (JISP) had the highest abundance (2705 individuals) and Martinak State Park (MSP) had the highest species …

Go to article

Ecology Of Greater Sage-Grouse Inhabiting The Southern Portion Of The Rich-Morgan-Summit Sage-Grouse Management Area, M. Brandon Flack Dec 2017

Ecology Of Greater Sage-Grouse Inhabiting The Southern Portion Of The Rich-Morgan-Summit Sage-Grouse Management Area, M. Brandon Flack

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are sagebrush obligates and are therefore considered to be key indicators of sagebrush ecosystem health. Sage-grouse populations have declined range-wide over the last century due to loss and fragmentation of sagebrush (Artemisia spp.) habitats. Sage-grouse populations found in large intact sagebrush landscapes are considered to be more resilient, however, some small isolated populations persist and thrive in fragmented landscapes. Because of Utah’s unique topography and geography, sage-grouse habitat is discontinuous and populations are naturally dispersed throughout the state in suitable intact blocks or in disconnected islands of sagebrush habitat. Thus, Utah populations …

Go to article

Bridging Post-Wildfire Communication Gaps Between Managers, Researchers, And Local Communities, Including A Biological Soil Crust Case Study, Hilary Louise Whitcomb Aug 2017

Bridging Post-Wildfire Communication Gaps Between Managers, Researchers, And Local Communities, Including A Biological Soil Crust Case Study, Hilary Louise Whitcomb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Immediately after a wildfire land managers act quickly to protect water supplies, soil stability, habitat, and forage. We don't currently understand how managers make trade-off decisions between social, political, and ecological factors in these tight timelines or if they are able to use new science. We do know ecosystems often benefit from local engagement, and new, scientifically-grounded methods that improve restoration efforts are needed. As post-wildfire timelines don’t often allow for outside input, I asked managers what they and stakeholders think about post-wildfire projects and what managers think about new science. I asked local citizens what they think about postwildfire …

Go to article

Natural And Anthropogenic Effects On Life History Characteristics In The Side-Blotched Lizard (Uta Stansburiana), Geoffrey David Stuart Smith Aug 2017

Natural And Anthropogenic Effects On Life History Characteristics In The Side-Blotched Lizard (Uta Stansburiana), Geoffrey David Stuart Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Survival is a prerequisite for successful reproduction, and is thus intertwined with fitness. Some physiological systems can improve survival, like the immune system, but compete with other processes for resources. Because animals evolved with resource limitation, it is important to understand how these resource-allocation decisions are made. To meet this end, I performed four investigations addressing how life-history characteristics shift in side-blotched lizards (Uta stansburiana) using laboratory studies and multi-year field sampling. First, I measured metabolic rates in response to different immune challenges and different energy states in male lizards. I found that, surprisingly, cutaneous biopsies were associated …

Go to article

A Comparison Of Five Statistical Methods For Predicting Stream Temperature Across Stream Networks, Maike F. Holthuijzen Aug 2017

A Comparison Of Five Statistical Methods For Predicting Stream Temperature Across Stream Networks, Maike F. Holthuijzen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The health of freshwater aquatic systems, particularly stream networks, is mainly influenced by water temperature, which controls biological processes and influences species distributions and aquatic biodiversity. Thermal regimes of rivers are likely to change in the future, due to climate change and other anthropogenic impacts, and our ability to predict stream temperatures will be critical in understanding distribution shifts of aquatic biota. Spatial statistical network models take into account spatial relationships but have drawbacks, including high computation times and data pre-processing requirements. Machine learning techniques and generalized additive models (GAM) are promising alternatives to the SSN model. Two machine learning …

Go to article

Pre-Dispersal Seed Predators And Fungi Differ In Their Effect On Luehea Seemannii Capsule Development, Seed Germination, And Dormancy Across Two Panamanian Forests, Pimonrat Tiansawat, Noelle G. Beckman, James W. Dalling Jul 2017

Pre-Dispersal Seed Predators And Fungi Differ In Their Effect On Luehea Seemannii Capsule Development, Seed Germination, And Dormancy Across Two Panamanian Forests, Pimonrat Tiansawat, Noelle G. Beckman, James W. Dalling

Biology Faculty Publications

Pre-dispersal seed predation can greatly reduce crop size affecting recruitment success. In addition, non-fatal damage by seed predators may allow infection by fungi responsible for post-dispersal seed losses. The objectives of this study were (1) to quantify pre-dispersal seed predation and fungal infection in a Neotropical tree species, Luehea seemannii, that produces dehiscent fruits and wind-dispersed seeds, and (2) to link pre-dispersal effects on seed quality to seed survival in the soil. To examine how seed predators and fungi influence seed losses, mesh exclosures, fungicide, and the combination of both treatments were applied to separate branches in the canopy …

Go to article

Relative Selection Strength: Quantifying Effectsize In Habitat- And Step-Selection Inference, Tal Avgar, Subhash R. Lele, Jonah L. Keim, Mark S. Boyce Jun 2017

Relative Selection Strength: Quantifying Effectsize In Habitat- And Step-Selection Inference, Tal Avgar, Subhash R. Lele, Jonah L. Keim, Mark S. Boyce

Wildland Resources Faculty Publications

Habitat-selection analysis lacks an appropriate measure of the ecological significance of the statistical estimates-a practical interpretation of the magnitude of the selection coefficients. There is a need for a standard approach that allows relating the strength of selection to a change in habitat conditions across space, a quantification of the estimated effect size that can be compared both within and across studies. We offer a solution, based on the epidemiological risk ratio, which we term the relative selection strength (RSS). For a "used-available" design with an exponential selection function, the RSS provides an appropriate interpretation of the magnitude of the …

Go to article

The Influence Of Wind Energy Development On Columbian Sharp-Tailed Grouse (Tympanuchus Phasianellus Columbianus) Breeding Season Ecology In Eastern Idaho, Matthew C. Proett May 2017

The Influence Of Wind Energy Development On Columbian Sharp-Tailed Grouse (Tympanuchus Phasianellus Columbianus) Breeding Season Ecology In Eastern Idaho, Matthew C. Proett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus; CSTG) has experienced range-wide population declines, primarily as a result of habitat loss or degradation, and currently occupies <10% of its historic range. Expansion of wind energy developments across the remaining occupied CSTG range has been identified as a potential threat to the species. To assess the potential influence of wind energy development of CSTG breeding season ecology, I captured and radio-marked 135 female CSTG drugin 2014-2015 at leks located between 0.1-13.8 km from wind turbines in restored grassland habitats. Using radio-telemetry, I monitored 147 nests and 68 broods and developed models to assess the influence of wind turbines, roads, habitat features temporal factors, and precipitation on CSTG nest site selection, nest survival, brood success, and chick survival. Female CSTG in my study selected nest sites in grassland habitats where >30% of the canopy cover in the nesting core use area was composed of forbs (i.e., broadleaf plants). The strength of selection for this habitat type increased as its availability increased on the landscape. Nest survival increased with higher visual obstruction readings (i.e., concealment) at the nest bowl and in grassland habitats where forb cover exceeded 30% in the nesting core use area. I did not detect an influence of wind turbines or …

Go to article

Spatial And Temporal Study Of Heat Transport Of Hydrothermal Features In Norris Geyser Basin, Yellowstone National Park, Ruba A. M. Mohamed May 2017

Spatial And Temporal Study Of Heat Transport Of Hydrothermal Features In Norris Geyser Basin, Yellowstone National Park, Ruba A. M. Mohamed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Monitoring thermal activity in Yellowstone National Park is required by the United States Congress to maintain the safety of the visitors and park service personnel and to protect the integrity of the park. This dissertation is part of a study initiated in the early 2000s to monitor the thermal activity in the park with focus on Norris Geyser Basin, the hottest geyser basin in the park. The study is considered the first multiple-year study in the basin which took place between August 2008 and October 2013. In this study, at least one thermal infrared image was acquired every year using …

Go to article

Interacting Effects Of Land Use And Climate On Rodent-Borne Pathogens In Central Kenya, Hillary S. Young, Douglas J. Mccauley, Rodolfo Dirzo, Charles L. Nunn, Michael G. Campana, Bernard Agwanda, Erik R. Otarola-Castillo, Robert M. Pringle, Kari E. Veblen, Daniel J. Salkeld, Kristin Stewardson, Robert Fleisher, Eric F. Lambin, Todd M. Palmer, Kristofer M. Helgen Apr 2017

Interacting Effects Of Land Use And Climate On Rodent-Borne Pathogens In Central Kenya, Hillary S. Young, Douglas J. Mccauley, Rodolfo Dirzo, Charles L. Nunn, Michael G. Campana, Bernard Agwanda, Erik R. Otarola-Castillo, Robert M. Pringle, Kari E. Veblen, Daniel J. Salkeld, Kristin Stewardson, Robert Fleisher, Eric F. Lambin, Todd M. Palmer, Kristofer M. Helgen

Wildland Resources Faculty Publications

Understanding the effects of anthropogenic disturbance on zoonotic disease risk is both a critical conservation objective and a public health priority. Here, we evaluate the effects of multiple forms of anthropogenic disturbance across a precipitation gradient on the abundance of pathogen-infected small mammal hosts in a multi-host, multi-pathogen system in central Kenya. Our results suggest that conversion to cropland and wildlife loss alone drive systematic increases in rodent-borne pathogen prevalence, but that pastoral conversion has no such systematic effects. The effects are most likely explained both by changes in total small mammal abundance, and by changes in relative abundance of …

Go to article

Climate Drives Fire Synchrony But Local Factors Control Fire Regime Change In Northern Mexico, Larissa L. Yocom Kent, Peter Z. Fule, J. Brown, E. Cerano, E. Cornejo-Oviedo, C. Cortés Montaño, S. A. Drury, D. A. Falk, J. Meunier, H. M. Poulos, C. N. Skinner, S. L. Stephens, J. Villanueva-Diaz Mar 2017

Climate Drives Fire Synchrony But Local Factors Control Fire Regime Change In Northern Mexico, Larissa L. Yocom Kent, Peter Z. Fule, J. Brown, E. Cerano, E. Cornejo-Oviedo, C. Cortés Montaño, S. A. Drury, D. A. Falk, J. Meunier, H. M. Poulos, C. N. Skinner, S. L. Stephens, J. Villanueva-Diaz

Wildland Resources Faculty Publications

The occurrence of wildfire is influenced by a suite of factors ranging from “top-down” influences (e.g., climate) to “bottom-up” localized influences (e.g., ignitions, fuels, and land use). We carried out the first broad-scale assessment of wildland fire patterns in northern Mexico to assess the relative influence of top-down and bottom-up drivers of fire in a region where frequent fire regimes continued well into the 20th century. Using a network of 67 sites, we assessed (1) fire synchrony and the scales at which synchrony is evident, (2) climate drivers of fire, and (3) asynchrony in fire regime changes. We found high …

Go to article

Hosts, Nesting Behavior, And Ecology Of Some North American Spider Wasps (Hymenoptera: Pompilidae), Ii, Frank E. Kurczewski, Glavis B. Edwards, James P. Pitts Jan 2017

Hosts, Nesting Behavior, And Ecology Of Some North American Spider Wasps (Hymenoptera: Pompilidae), Ii, Frank E. Kurczewski, Glavis B. Edwards, James P. Pitts

Biology Faculty Publications

This monograph is a continuation of a multiyear study of the genera and species of North American spider wasps (Pompilidae) and their spider host families, genera and species, nesting behavior, ecology, and natural communities. The study enlarges and enhances host preference, nesting behavior, and ecological information for 77 North American pompilid taxa. The first North American Pompilidae records for the families Tengellidae and Segestriidae, both from central coastal California, are reported herein. New host spider genera and species are listed for many of the pompilid species, including the first North American host record for Dipogon (Dipogon) g. graenicheri …

Go to article

Temporal Foraging Patterns Of Nonnative Frogs (Eleutherodactylus Coqui) In Hawaii, Arthur C. Wallis, Robyn L. Smith, Karen H. Beard Dec 2016

Temporal Foraging Patterns Of Nonnative Frogs (Eleutherodactylus Coqui) In Hawaii, Arthur C. Wallis, Robyn L. Smith, Karen H. Beard

Wildland Resources Faculty Publications

The Puerto Rican Coqui Frog (Eleutherodactylus coqui) is a nocturnal, invasive species that was introduced into Hawaii in the 1980s. Because they reach extremely high densities (up to 90,000 frogs/ha), they have the potential to affect invertebrate prey communities. Previously, researchers used frogs collected only at night to characterize their prey. Because Coquis use retreat sites near the forest floor during the day and understory perch sites at night, frogs collected at night might show different amounts and types of prey than would frogs collected in the morning. We analyzed stomach contents of 435 frogs collected in the morning (0300–0600 …

Go to article

Simple Soil Quality Tests And Organic Management Practices For Orchards In The Intermountain West, Esther Oline Thomsen Dec 2016

Simple Soil Quality Tests And Organic Management Practices For Orchards In The Intermountain West, Esther Oline Thomsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil health is often overlooked as a long-term management strategy as growers face an increasing number of short-term management challenges in the Intermountain West. The costs of inputs are rising and water resources are becoming more limited. Soil with poor health typically requires more amendments and fertlizers to meet crop needs. Soil health tests can help reveal management practices that reduce soil health, as well as those that improve soil health. Practices known to improve soil health are reduced to no tillage, cover crop use- especially legumes, and addition of mulch and other organic materials. Soil health testing is not …

Go to article

Different Prey Resources Suggest Little Competition Between Non-Native Frogs And Insectivorous Birds Despite Isotopic Niche Overlap, Robyn L. Smith, Karen H. Beard, Aaron B. Shiels Nov 2016

Different Prey Resources Suggest Little Competition Between Non-Native Frogs And Insectivorous Birds Despite Isotopic Niche Overlap, Robyn L. Smith, Karen H. Beard, Aaron B. Shiels

Wildland Resources Faculty Publications

Non-native amphibians often compete with native amphibians in their introduced range, but their competitive effects on other vertebrates are less well known. The Puerto Rican coqui frog (Eleutherodactylus coqui) has colonized the island of Hawaii, and has been hypothesized to compete with insectivorous birds and bats. To address if the coqui could compete with these vertebrates, we used stable isotope analyses to compare the trophic position and isotopic niche overlap between the coqui, three insectivorous bird species, and the Hawaiian hoary bat. Coquis shared similar trophic position to Hawaii amakihi, Japanese white-eye, and red-billed leiothrix. Coquis were about 3 ‰ …

Go to article

A Life-History Perspective On The Demographic Drivers Of Structured Population Dynamics In Changing Environments, David N. Koons, David T. Iles, Michael Schaub, Hal Caswell Jul 2016

A Life-History Perspective On The Demographic Drivers Of Structured Population Dynamics In Changing Environments, David N. Koons, David T. Iles, Michael Schaub, Hal Caswell

Wildland Resources Faculty Publications

Current understanding of life-history evolution and how demographic parameters contribute to population dynamics across species is largely based on assumptions of either constant environments or stationary environmental variation. Meanwhile, species are faced with non-stationary environmental conditions (changing mean, variance, or both) created by climate and landscape change. To close the gap between contemporary reality and demographic theory, we develop a set of transient life table response experiments (LTREs) for decomposing realised population growth rates into contributions from specific vital rates and components of population structure. Using transient LTREs in a theoretical framework, we reveal that established concepts in population biology …

Go to article

Study On The Proceeding Of Hydraulic Problem Of Simulating Natural Fish Passage, Zhijuan Wang, Qingyuan Yang, Minghai Huang, Yong He Jun 2016

Study On The Proceeding Of Hydraulic Problem Of Simulating Natural Fish Passage, Zhijuan Wang, Qingyuan Yang, Minghai Huang, Yong He

International Symposium on Hydraulic Structures

Fish passage in water conservancy projects is an important means of improving river connectivity, and reducing the impact on the ecological environment. Simulating natural fish passage, which aims at the purpose of the river ecological corridor by the means of ecological optimization on the structure and section type based on the traditional fish passage, is promoted and applied in recent years gradually. At the same time, the hydraulic research related to the simulating natural fish passage has made great progress. In this paper, we firstly collected and summarized the research experience of the domestic and foreign typical fish passage, analyzed …

Go to article

The Plight Of Aspen: Emerging As A Beneficiary Of Wolf Restoration On Yellowstone’S Northern Range, John Klaptosky Jun 2016

The Plight Of Aspen: Emerging As A Beneficiary Of Wolf Restoration On Yellowstone’S Northern Range, John Klaptosky

Aspen Bibliography

No abstract provided.

Go to article

Assessing Plant Community Structure In The Upper Las Vegas Wash Conservation Transfer Area, Nevada: The Influence Of Biotic And Abiotic Variables, Amy A. Croft May 2016

Assessing Plant Community Structure In The Upper Las Vegas Wash Conservation Transfer Area, Nevada: The Influence Of Biotic And Abiotic Variables, Amy A. Croft

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecological communities are complex, the structure of which is composed of interactions between multiple community characteristics and the abiotic and biotic factors shaping them. Because of this complexity, ecological studies are generally limited in scope and size, often dissecting communities into their component parts to examine them piece by piece. While this might be the most practical method to study communities, this approach often neglects other characteristics that, with their inclusion, would provide a more complete picture of community ecology. The studies described in this dissertation were conducted in an effort to synthesize the complexity that is inherent in ecological …

Go to article

Stable Isotopes And The Ecology And Physiology Of Reptiles, Andrew M. Durso May 2016

Stable Isotopes And The Ecology And Physiology Of Reptiles, Andrew M. Durso

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When animals don’t have enough food, they have to “choose” between “spending” their limited energy on themselves or on their offspring. Biologists think that reptiles can make this choice quickly in response to different environments. But, it can be hard to study these choices because it is hard to convert between, for example, the number of eggs laid and the speed of healing a wound. By using stable isotope chemistry, we can collect more detailed and comparable information about how lizards and other animals spend their limited resources than with any other method. For example, lizards in the wild have …

Go to article

Physically Based Modeling Of The Impacts Of Climate Change On Streamflow Regime, Nazmus Shams Sazib May 2016

Physically Based Modeling Of The Impacts Of Climate Change On Streamflow Regime, Nazmus Shams Sazib

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the implications of climate change on streamflow regime is complex as changes in climate vary over space and time. However, a better understanding of the impact of climate change is required for identifying how stream ecosystems vulnerable to these changes, and ultimately to guide the development of robust strategies for reducing risk in the face of changing climatic conditions. Here I used physically based hydrologic modeling to improve understanding of how climate change may impact streamflow regimes and advance some of the cyberinfrastructure and GIS methodologies that support physically based hydrologic modeling by: (1) using a physically based model …

Go to article

Comparing Conventional And Noninvasive Monitoring Techniques For Assessing Cougar Population Size In The Southern Greater Yellowstone Ecosystem, Peter D. Alexander May 2016

Comparing Conventional And Noninvasive Monitoring Techniques For Assessing Cougar Population Size In The Southern Greater Yellowstone Ecosystem, Peter D. Alexander

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Determining the abundance or density of wildlife populations is needed for informed decision-making by wildlife biologists. Cougars (Puma concolor), however, are a highly secretive species occurring at very low densities across the landscape, and thus their populations are difficult for biologists to accurately assess. The conventional, and most trusted, method entails physically trapping and radio-collaring as many cougars as possible in a population, and then performing a simple count to determine a minimum population size. While accurate, this method is prohibitively expensive, logistically challenging, and behaviorally disruptive to the study animal. Many noninvasive surveying techniques, such as camera …

Go to article

Special Topic: Wildlife And Wing Energy: Are They Compatible? Introduction, Michael Hutchins, Bruce D. Leopold Jan 2016

Special Topic: Wildlife And Wing Energy: Are They Compatible? Introduction, Michael Hutchins, Bruce D. Leopold

Human–Wildlife Interactions

No abstract provided.

Go to article

The Importance Of Motivation, Weapons, And Foul Odors In Driving Encounter Competition In Carnivores, Maximilian L. Allen, Christopher C. Wilmers, L. Mark Elbroch, Julie M. Golla, Heiko U. Wittmer Jan 2016

The Importance Of Motivation, Weapons, And Foul Odors In Driving Encounter Competition In Carnivores, Maximilian L. Allen, Christopher C. Wilmers, L. Mark Elbroch, Julie M. Golla, Heiko U. Wittmer

Environment and Society Faculty Publications

Encounter competition is interference competition in which animals directly contend for resources. Ecological theory predicts the trait that determines the resource holding potential (RHP), and hence the winner of encounter competition, is most often body size or mass. The difficulties of observing encounter competition in complex organisms in natural environments, however, has limited opportunities to test this theory across diverse species. We studied the outcome of encounter competition contests among mesocarnivores at deer carcasses in California to determine the most important variables for winning these contests. We found some support for current theory in that body mass is important in …

Go to article

Modelling Water Uptake Provides A New Perspective On Grass And Tree Coexistence, Michael G. Mazzacavallo, Andrew Kulmatiski Dec 2015

Modelling Water Uptake Provides A New Perspective On Grass And Tree Coexistence, Michael G. Mazzacavallo, Andrew Kulmatiski

Wildland Resources Faculty Publications

Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize …

Go to article

Thermal Patterns Constrain Diurnal Behavior Of A Ground-Dwelling Bird, J. Matthew Carroll, Craig A. Davis, R. Dwayne Elmore, Samuel D. Fuhlendorf, Eric T. Thacker Nov 2015

Thermal Patterns Constrain Diurnal Behavior Of A Ground-Dwelling Bird, J. Matthew Carroll, Craig A. Davis, R. Dwayne Elmore, Samuel D. Fuhlendorf, Eric T. Thacker

Wildland Resources Faculty Publications

Recently, gaining knowledge about thermal refuges for vulnerable species has been a major focal point of ecological studies, and this focus has been heightened by predicted temperature increases associated with global climate change. To better understand how organisms respond to thermal landscapes and extremes, we investigated the thermal ecology of a gallinaceous bird species (northern bobwhite; Colinus virginianus, hereafter bobwhite) during a key life history period. Specifically, our study focused on the brood-rearing period of precocial bobwhite chicks associated with brood-attending adults. We measured site-specific black bulb temperatures (Tbb) and vegetation characteristics across 38 brood tracking days and 68 random …

Go to article

Modeling The Ecological Consequences Of Visitor Behavior In Off-Trail Areas Of Dispersed Recreation Use, Ashley L. D'Antonio Aug 2015

Modeling The Ecological Consequences Of Visitor Behavior In Off-Trail Areas Of Dispersed Recreation Use, Ashley L. D'Antonio

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Parks and protected areas are often created to protect important social, ecological, or cultural resources from impairment. In the United States, a large majority of these parks and protected areas are also public land where recreational activities such as hiking or scenic driving are allowed. Managers of many parks and protected areas must therefore try to protect resources while also allowing for recreation use that may put these resources at risk for damage. The field of recreation ecology is interested in understanding how recreation use in parks and protected areas can sometimes cause ecological impacts to vegetation, soil, wildlife, water, …

Go to article

First Prev Next Last