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Articles 331 - 360 of 1585

Full-Text Articles in Ecology and Evolutionary Biology

Susceptibility Of High-Elevation Forests To Mountain Pine Beetle (Dendroctonus Ponderosae Hopkins) Under Climate Change, David N. Soderberg Aug 2021

Susceptibility Of High-Elevation Forests To Mountain Pine Beetle (Dendroctonus Ponderosae Hopkins) Under Climate Change, David N. Soderberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Across western North America, pine forests are important for timber, wildlife habitat, and at high elevations are important for water retention and yield from rain and snowmelt. The mountain pine beetle (MPB) is one of the most significant disturbance agents shaping pine forests, and like all insects, temperature is a major driver of its population success and the dynamics of the landscapes that they inhabit. Changing temperature regimes can therefore directly influence MPB population persistence at a particular location, in addition to potential shifts in the range boundaries that they inhabit. MPB is currently expanding its range northward in British …


Climate-Driven Impacts Of Warming And Grazing On Sub-Arctic Coastal Wetlands In Alaska, Ryan T. Choi Aug 2021

Climate-Driven Impacts Of Warming And Grazing On Sub-Arctic Coastal Wetlands In Alaska, Ryan T. Choi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate change is rapidly warming the Arctic, especially at lower latitudes. Warmer temperatures and earlier springs are altering the timing of plants and animals, especially for long-distance migratory herbivores. Changes in the timing of both plants and herbivores have the potential to impact plant productivity and nutrient cycling, while also altering plant community diversity and composition.

In chapter 2, I conducted a field experiment to investigate how earlier growing seasons and differences in arrival times of migratory geese influence physical traits of sedge forage species. I found that both an earlier growing season and late grazing by geese had similar …


Dietary Shifts Related To Water Availability And The Demographic Response To Changing Prey Abundance Of Carnivores In The West Desert, Utah, Ashley E. Hodge Aug 2021

Dietary Shifts Related To Water Availability And The Demographic Response To Changing Prey Abundance Of Carnivores In The West Desert, Utah, Ashley E. Hodge

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The decrease in number and range of North American large carnivores, has often all owed smaller carnivores ( < 15 kg) to fill the role of the top predator. This has favored some carnivores such as coyotes (Canis latrans), who have expanded their distribution. Other small carnivores such as kit foxes (Vulpes macrotis) have experienced a range shrinkage and their population status throughout the United States is a concern. Historically, western U.S. natural resource management agencies installed artificial water sources to assist desert wildlife, but some researchers believe the access to water allowed more coyotes to live in Utah’s West Desert. In the late-1980s, research proposed that without free drinking water, coyotes would have to triple …


Insights On Reticulate Evolution In Ferns, With Special Emphasis On The Genus Ceratopteris, Sylvia P. Kinosian Aug 2021

Insights On Reticulate Evolution In Ferns, With Special Emphasis On The Genus Ceratopteris, Sylvia P. Kinosian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The history of life is often viewed as a evenly branching tree; however, in reality it is more like a tangled hedgerow. Many groups of organisms are known to have such a net-like or reticulate evolutionary history, but it is particularly common in ferns and lycophytes (also known as pteridophytes). This dissertation investigates how net-like evolution affects different groups of ferns, with a special emphasis on the model species C-fern (Ceratopteris richardii, also called the antler or water sprite fern). Genomic data are utilized to under-stand hybridization, cryptic species and reticulate evolution in two groups of ferns. The …


Predator Defense And Host Selection Behavior Of Billbugs (Coleoptera: Dryophthoridae), Desireè M. Wickwar Aug 2021

Predator Defense And Host Selection Behavior Of Billbugs (Coleoptera: Dryophthoridae), Desireè M. Wickwar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Billbugs are a complex of weevils that feed on the roots of turfgrass, causing severe damage to the plants. These pests are traditionally managed with applications of insecticides. However, there is a need for non-chemical management tools. Here I investigate billbug behavior in relation to two potential avenues for more sustainable management: using resident predators to suppress billbugs (Chapter II) and selecting specific turfgrasses that resist billbug damage (Chapter III). In Chapter II, I investigate the effects of predator presence and cues associated with their presence on billbug behavior. Though resident predators contribute very little to billbug suppression through directly …


A Novel Method For Detecting Wild Boar Presence, Giovanna Massei, Dave P. Cowan, Julia Coats Jul 2021

A Novel Method For Detecting Wild Boar Presence, Giovanna Massei, Dave P. Cowan, Julia Coats

Human–Wildlife Interactions

Populations of wild boar and feral pigs (Sus scrofa) are increasing in numbers and distribution worldwide, in parallel with their significant environmental and economic impact. Reliable methods to detect the presence of this species are needed for monitoring its natural range expansion and its occurrence in areas where animals have been deliberately or accidentally introduced. The main aim of this study, carried out in English woodlands recently colonized by wild boar, was to assess the effectiveness of a birch wood tar-based compound, to detect the presence of this species in presence/absence surveys. A pilot trial in woodlands where …


Intensive Hunting Pressure Changes Local Distribution Of Wild Boar, Jakub Drimaj, Jiří Kamler, Radim Plhal, Přemysl Janata, Zdeněk Adamec, Miloslav Homolka Jul 2021

Intensive Hunting Pressure Changes Local Distribution Of Wild Boar, Jakub Drimaj, Jiří Kamler, Radim Plhal, Přemysl Janata, Zdeněk Adamec, Miloslav Homolka

Human–Wildlife Interactions

Wild boar (Sus scrofa) is now an important species of wild ungulates in Central Europe. Next to conflicts of wild boar with agriculture, the main threat of wild boar presence lies in the expansion of African swine fever across Europe. The regulation of the wild boar population is complicated by the high reproduction rate and intelligent behavior of the species, which limits hunting effectiveness. We analyzed the spatial behavior of wild boar in an environment with a lack of natural food resources. The study area consisted of a forest complex (1,283 ha) with 2 areas. In the “risk” …


Book Review: The Wildlife Techniques Manual, Eighth Edition, Justin Small Jul 2021

Book Review: The Wildlife Techniques Manual, Eighth Edition, Justin Small

Human–Wildlife Interactions

Wildlife researchers and managers are consistently tackling ecological and conservation issues that are increasing in complexity and scope. Wildlife issues often span beyond singular research frameworks and management jurisdictions, preventing modern wildlife conservation from operating in mutually exclusive arenas (i.e., research or management). As a wildlife researcher whose research is conducted on both public and private rangelands, and across multiple stakeholder groups, techniques to answer difficult questions and offer time-sensitive solutions must pull from both research and management arenas. Historically, book or journal resources that wildlife professionals could readily access for necessary scientific guidance were contained in many documents, making …


Utility Of Visual Counts For Determining Efficacy Of Management Tools For California Ground Squirrels, Roger A. Baldwin, Theresa A. Becchetti, Niamh Quinn, Ryan Meinerz Jul 2021

Utility Of Visual Counts For Determining Efficacy Of Management Tools For California Ground Squirrels, Roger A. Baldwin, Theresa A. Becchetti, Niamh Quinn, Ryan Meinerz

Human–Wildlife Interactions

Visual counts are frequently used to assess efficacy of management tools for ground squirrels (Marmotini), but the effectiveness of this approach has not been assessed for many ground squirrel species including California ground squirrels (Otospermophilus spp.). As such, we used visual counts of California ground squirrels to determine the efficacy of diphacinone-treated oat groat applications in rangelands in central California, USA, and compared those results to efficacy values derived from the use of radio-collared ground squirrels in the same plots. We also used location data of radio-collared ground squirrels to explore the size of buffer zone needed around census …


Collaborative Research: Ecological Legacy Effects Of Megacarcasses In African Savanna Ecosystems, Johan Du Toit Jul 2021

Collaborative Research: Ecological Legacy Effects Of Megacarcasses In African Savanna Ecosystems, Johan Du Toit

Funded Research Records

No abstract provided.


Temporal Trends And Drivers Of Mountain Lion Depredation In California, Usa, Justin A. Dellinger, Daniel K. Macon, Jaime L. Rudd, Deana L. Clifford, Steven G. Torres Jul 2021

Temporal Trends And Drivers Of Mountain Lion Depredation In California, Usa, Justin A. Dellinger, Daniel K. Macon, Jaime L. Rudd, Deana L. Clifford, Steven G. Torres

Human–Wildlife Interactions

Increasing human populations and expanding development across the globe necessitate continual progress in understanding and mitigating human–wildlife conflict. California, USA has the largest human population and at least half of the state is suitable mountain lion (Puma concolor) habitat. The juxtaposition of high human abundance within and adjacent to mountain lion habitat make California relevant for understanding human–large carnivore conflict. We compiled 7,719 confirmed incidents of mountain lions depredating domestic animals over a 48-year period (1972–2019) to examine temporal trends in mountain lion depredations as well as factors influencing annual depredation rates at the county level. Linear regressions …


Enhancing Existing Isolated Underpasses With Fencing Reduces Wildlife Crashes And Connects Habitat, Bridget M. Donaldson, Kaitlyn E. M. Elliott Jul 2021

Enhancing Existing Isolated Underpasses With Fencing Reduces Wildlife Crashes And Connects Habitat, Bridget M. Donaldson, Kaitlyn E. M. Elliott

Human–Wildlife Interactions

The impact of wildlife–vehicle collisions on drivers and wildlife populations has been gaining attention in the United States. Given the established success of wildlife crossings with fencing in reducing wildlife crashes and connecting habitat, information is needed on cost-effective means of implementation for departments of transportation. When wildlife crossings are constructed, they are often built into new road projects as a series of 2 or more underpasses and/or overpass structures connected by exclusionary fencing. Given limited transportation budgets and the prevalence of maintenance activities more so than new construction in many states, enhancing existing underpasses on previously constructed roads has …


Availability And Structure Of Coarse Woody Debris In Hemiboreal Mature To Old-Growth Aspen Stands And Its Implications For Forest Carbon Pool, Silva Šēnhofa, Guntars Šnepsts, Kārlis Bičkovskis, Ieva Jaunslaviete, Līga Liepa, Inga Straupe, Āris Jansons Jul 2021

Availability And Structure Of Coarse Woody Debris In Hemiboreal Mature To Old-Growth Aspen Stands And Its Implications For Forest Carbon Pool, Silva Šēnhofa, Guntars Šnepsts, Kārlis Bičkovskis, Ieva Jaunslaviete, Līga Liepa, Inga Straupe, Āris Jansons

Aspen Bibliography

European aspen deadwood is extensively studied as a habitat for saproxylic species, while less is known of its dynamics and role in carbon sequestration. We studied unmanaged mature (41–60 years), moderately overmature (61–80 years), overmature (81–100 years), and old-growth (101–140 years) and managed mature and moderately overmature aspen stands on fertile mineral soils. In unmanaged stands, marginal mean CWD volume was from 67.3 ± 12.1 m3 ha−1 in moderately overmature to 92.4 ± 5.1 m3 ha−1 in old-growth stands, with corresponding marginal mean CWD carbon pool 8.2 ± 1.6 t ha−1 and 12.5 ± 0.7 …


Coarse Woody Debris Decomposition Assessment Tool: Model Validation And Application, Zhaohua Dai, Carl C. Trettin, Andrew J. Burton, Martin F. Jurgensen, Deborah S. Page-Dumroese, Brian T. Forschler, Jonathan S. Schilling, Daniel L. Lindner Jul 2021

Coarse Woody Debris Decomposition Assessment Tool: Model Validation And Application, Zhaohua Dai, Carl C. Trettin, Andrew J. Burton, Martin F. Jurgensen, Deborah S. Page-Dumroese, Brian T. Forschler, Jonathan S. Schilling, Daniel L. Lindner

Aspen Bibliography

Coarse woody debris (CWD) is a significant component of the forest biomass pool; hence a model is warranted to predict CWD decomposition and its role in forest carbon (C) and nutrient cycling under varying management and climatic conditions. A process-based model, CWDDAT (Coarse Woody Debris Decomposition Assessment Tool) was calibrated and validated using data from the FACE (Free Air Carbon Dioxide Enrichment) Wood Decomposition Experiment utilizing pine (Pinus taeda), aspen (Populous tremuloides) and birch (Betula papyrifera) on nine Experimental Forests (EF) covering a range of climate, hydrology, and soil conditions across the continental USA. …


Tree Establishment On Post-Mining Waste Soils: Species, Density, And Mixture Effects, Degi Harja Asmara, Suzanne Allaire, Meine Van Noordwijk, Damase P. Khasa Jun 2021

Tree Establishment On Post-Mining Waste Soils: Species, Density, And Mixture Effects, Degi Harja Asmara, Suzanne Allaire, Meine Van Noordwijk, Damase P. Khasa

Aspen Bibliography

Tree establishment to restore degraded boreal post-mining lands is challenged by low soil productivity, a harsh microclimate, and potentially high contaminant levels. The use of mixed vegetation can facilitate the microclimate but increase competition for soil resources. A statistical accounting of plant–plant interactions and adaptation to multispecies conditions is hard to achieve in field experiments; trials under controlled conditions can distinguish effects of planting density and species interactions in the early stages of plant establishment. A greenhouse trial was established in containers (“mesocosms”) with waste rock or fine tailings from gold mines. Pregerminated (1-week-old) seedlings (Alnus viridis subsp. crispa …


Plant-Soil Feedbacks Help Explain Biodiversity-Productivity Relationships, Leslie E. Forero, Andrew Kulmatiski, Josephine Grenzer, Jeanette M. Norton Jun 2021

Plant-Soil Feedbacks Help Explain Biodiversity-Productivity Relationships, Leslie E. Forero, Andrew Kulmatiski, Josephine Grenzer, Jeanette M. Norton

Wildland Resources Student Research

Species-rich plant communities can produce twice as much aboveground biomass as monocultures, but the mechanisms remain unresolved. We tested whether plant-soil feedbacks (PSFs) can help explain these biodiversity-productivity relationships. Using a 16-species, factorial field experiment we found that plants created soils that changed subsequent plant growth by 27% and that this effect increased over time. When incorporated into simulation models, these PSFs improved predictions of plant community growth and explained 14% of overyielding. Here we show quantitative, field-based evidence that diversity maintains productivity by suppressing plant disease. Though this effect alone was modest, it helps constrain the role of factors, …


Spatial And Temporal Variation Of Epigaeic Beetle Assemblages (Coleoptera, Carabidae, Staphylinidae) In Aspen-Dominated Mixedwood Forests Across North-Central Alberta, H. E. James Hammond, Sergio García-Tejero, Greg R. Pohl, David W. Langor, John R. Spence Jun 2021

Spatial And Temporal Variation Of Epigaeic Beetle Assemblages (Coleoptera, Carabidae, Staphylinidae) In Aspen-Dominated Mixedwood Forests Across North-Central Alberta, H. E. James Hammond, Sergio García-Tejero, Greg R. Pohl, David W. Langor, John R. Spence

Aspen Bibliography

Epigaeic beetle assemblages were surveyed using continuous pitfall trapping during the summers of 1992 and 1993 in six widely geographically distributed locations in Alberta’s aspen-mixedwood forests prior to initial forest harvest. Species composition and turnover (β-diversity) were evaluated on several spatial scales ranging from Natural Regions (distance between samples 120–420 km) to pitfall traps (40–60 m). A total of 19,885 ground beetles (Carabidae) representing 40 species and 12,669 rove beetles (non-Aleocharinae Staphylinidae) representing 78 species was collected. Beetle catch, species richness, and diversity differed significantly among the six locations, as did the identity of dominant species. Beetle species composition differed …


Low-Density Aspen Seedling Establishment Is Widespread Following Recent Wildfires In The Western United States, Mark R. Kreider, Larissa L. Yocom Jun 2021

Low-Density Aspen Seedling Establishment Is Widespread Following Recent Wildfires In The Western United States, Mark R. Kreider, Larissa L. Yocom

Wildland Resources Faculty Publications

Sexual regeneration is increasingly recognized as an important regeneration pathway for aspen in the western United States, a region previously thought to be too dry for seedling establishment except for during unusually wet periods. Because of this historical assumption, information on aspen seedling establishment and factors influencing its occurrence is limited and frequently anecdotal. We conducted a systematic field survey of 15 recent fire footprints that burned in 2018 in the western United States to quantify how common aspen seedling establishment is following fire and to identify factors associated with establishment. We found aspen seedling establishment in 12 of 15 …


Recreation Effects On Wildlife: A Review Of Potential Quantitative Thresholds, Jeremy S. Dertien, Courtney L. Larson, Sarah E. Reed May 2021

Recreation Effects On Wildlife: A Review Of Potential Quantitative Thresholds, Jeremy S. Dertien, Courtney L. Larson, Sarah E. Reed

All Publications

Outdoor recreation is increasingly recognised for its deleterious effects on wildlife individuals and populations. However, planners and natural resource managers lack robust scientific recommendations for the design of recreation infrastructure and management of recreation activities. We reviewed 38 years of research on the effect of non-consumptive recreation on wildlife to attempt to identify effect thresholds or the point at which recreation begins to exhibit behavioural or physiological change to wildlife. We found that 53 of 330 articles identified a quantitative threshold. The majority of threshold articles focused on bird or mammal species and measured the distance to people or to …


Splitting The Difference: Heterogeneous Soil Moisture Availability Affects Aboveground And Belowground Reserve And Mass Allocation In Trembling Aspen, Ashley T. Hart, Morgane Merlin, Erin Wiley, Simon M. Landhäusser May 2021

Splitting The Difference: Heterogeneous Soil Moisture Availability Affects Aboveground And Belowground Reserve And Mass Allocation In Trembling Aspen, Ashley T. Hart, Morgane Merlin, Erin Wiley, Simon M. Landhäusser

Aspen Bibliography

When exploring the impact of resource availability on perennial plants, artificial treatments often apply conditions homogeneously across space and time, even though this rarely reflects conditions in natural systems. To investigate the effects of spatially heterogeneous soil moisture on morphological and physiological responses, trembling aspen (Populus tremuloides) saplings were used in a split-pot experiment. Following the division of the root systems, saplings were established for a full year and then subjected to either heterogeneous (portion of the root system exposed to non-lethal drought) or homogeneous (whole root system exposed to non-lethal drought or well-watered) treatments. Above- and belowground …


Chloroplast Genomes In Populus (Salicaceae): Comparisons From An Intensively Sampled Genus Reveal Dynamic Patterns Of Evolution, Jiawei Zhou, Shuo Zhang, Jie Wang, Hongmei Shen, Bin Ai, Wei Gao, Cuijun Zhang, Qili Fei, Daojun Yuan, Zhiqiang Wu, Luke R. Tembrock, Sen Li, Cuiha Gu, Xuezhu Liao May 2021

Chloroplast Genomes In Populus (Salicaceae): Comparisons From An Intensively Sampled Genus Reveal Dynamic Patterns Of Evolution, Jiawei Zhou, Shuo Zhang, Jie Wang, Hongmei Shen, Bin Ai, Wei Gao, Cuijun Zhang, Qili Fei, Daojun Yuan, Zhiqiang Wu, Luke R. Tembrock, Sen Li, Cuiha Gu, Xuezhu Liao

Aspen Bibliography

The chloroplast is one of two organelles containing a separate genome that codes for essential and distinct cellular functions such as photosynthesis. Given the importance of chloroplasts in plant metabolism, the genomic architecture and gene content have been strongly conserved through long periods of time and as such are useful molecular tools for evolutionary inferences. At present, complete chloroplast genomes from over 4000 species have been deposited into publicly accessible databases. Despite the large number of complete chloroplast genomes, comprehensive analyses regarding genome architecture and gene content have not been conducted for many lineages with complete species sampling. In this …


Environmental Racism In A Growing City: Investigating Demographic Shifts In Salt Lake City's Polluted Neighborhoods, Emma Nathel Jones May 2021

Environmental Racism In A Growing City: Investigating Demographic Shifts In Salt Lake City's Polluted Neighborhoods, Emma Nathel Jones

Undergraduate Honors Capstone Projects

Studies investigating the spatial distribution of environmental hazards have repeatedly demonstrated the existence of environmental racism -- the disproportionate impact of environmental hazards on communities of color. We aim to contribute to research on environmental racism by asking how relationships between race and hazard exposure change over time. Our study area, Salt Lake City (SLC), UT, USA is one of the largest cities in the intermountain west and is expected to see continued population growth. SLC was 99% white from 1860-1950. 2019 census estimates indicate that SLC is becoming more racially diverse with 35.6% of the population identifying as racial …


Pando's Lessons: Restoration Of A Giant Aspen Clone, Paul C. Rogers, Jody Gale, Darren Mcavoy May 2021

Pando's Lessons: Restoration Of A Giant Aspen Clone, Paul C. Rogers, Jody Gale, Darren Mcavoy

Aspen Bibliography

A 106 acre (43 ha) aspen clone lives in the Fishlake National Forest in south-central Utah. Clones are comprised of multiple aspen stems, called ramets, which are genetically identical. This particular colony of ramets was named “Pando” (Latin for “I spread”) by researchers believing it to be the largest living organism by mass on earth. Recently, forest managers have noted a rapid dying of mature stems without recruitment of younger trees. This unsustainable situation has galvanized restoration efforts at Pando. Human interventions caused this imbalance; restoration will rely on protection, monitoring, and innovation. As a laboratory, this forest icon may …


An Eulerian Perspective On Spring Migration In Mule Deer, Tatum Del Bosco May 2021

An Eulerian Perspective On Spring Migration In Mule Deer, Tatum Del Bosco

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many herbivores travel between low-elevation winter ranges and high-elevation summer sites. These seasonal movements allow them to avoid deep snow cover, ensure access to favorable habitat, and maximize food intake throughout the year. During the spring season, plants at lower elevations green up earlier at lower elevations than at higher elevations. It has been shown that individual animals will track this vegetation growth during their spring migration, which allows them to maximize forage intake coming out of the nutrient scarce winter. This phenomena has previously been studied by monitoring individual movement trajectories, but it is unknown how this pattern scales …


Interactive Effects Of Soil And Browsing On Big Sagebrush: Implications For Restoration Success, Kyle Nehring May 2021

Interactive Effects Of Soil And Browsing On Big Sagebrush: Implications For Restoration Success, Kyle Nehring

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

Heterogeneity in landscape conditions (e.g., soil types) precludes a “one size fits all” management strategy across large landscapes. New management approaches that explicitly account for heterogeneous landscapes (and the variable conditions therein) will be required to maintain habitat quality. In particular, we require an improved mechanistic understanding of how the outcomes of conservation and restoration actions are contingent upon a) contextual abiotic factors (e.g., moisture availability mediated by soils and precipitation) and b) their interactions with biotic factors (e.g., browsing wildlife).

We propose to answer fundamental questions about how big sagebrush (Artemisia tridentata), the foundational species for sagebrush …


Taphonomy Of Late Jurassic (Tithonian) Morrison Formation Apatosaurus Sp. Vertebrae Found Associated With Teeth From Allosaurus Sp. And Ceratosaurus Sp., And Body Size Extrapolation From The Associated Theropod Teeth., Greg C. Agyan May 2021

Taphonomy Of Late Jurassic (Tithonian) Morrison Formation Apatosaurus Sp. Vertebrae Found Associated With Teeth From Allosaurus Sp. And Ceratosaurus Sp., And Body Size Extrapolation From The Associated Theropod Teeth., Greg C. Agyan

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

An Apatosaurus sp. locality from Dinosaur National Monument designated DNM-15 was excavated in 1985, and associated with two Allosaurus teeth and one Ceratosaurus tooth that were near one of the caudal vertebrae. The Ceratosaurus tooth was buried between an overlying rib and that same caudal vertebra. The caudal vertebrae of the DNM-15 Apatosaurus were intact and articulated, but the anterior skeleton was mostly absent, with a row of articulated sacral vertebrae in close association with a femur. Two other Allosaurus teeth were reported near the preserved ilium of the Apatosaurus, but they could not be located in the collections. …


Mechanisms Of Overyielding And Coexistence In Diverse Tallgrass Prairie Communities, Leslie E. Forero May 2021

Mechanisms Of Overyielding And Coexistence In Diverse Tallgrass Prairie Communities, Leslie E. Forero

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants compete for the same basic nutrient and water resources. According to the competitive exclusion principle, when a substantial overlap in resource pools exists, the best competitor for resources should drive all other species to extinction. The ability for plants to coexist in violation of the competitive exclusion principle is the “biodiversity paradox”. Coexistence is actually beneficial for plants: as species diversity increases, you typically see increases in plant biomass production (known as the biodiversity-productivity relationship). The mechanisms behind coexistence and the biodiversity-productivity relationship remain an ecological mystery. One hypothesis is that plants obtain water and nutrients from different places …


Range-Wide Migratory Connectivity Of Painted Buntings, Andrew J. Sharp May 2021

Range-Wide Migratory Connectivity Of Painted Buntings, Andrew J. Sharp

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Painted Bunting (Passerina cirus) is a small (~16g), short/medium-distance migratory songbird that is listed as a species of conservation concern by the US Fish and Wildlife Service. Painted Buntings breed in two distinct populations, one eastern population and one interior population, separated by a 500 km gap that stretches from Mississippi to Georgia. I analyzed tracking data from 112 Painted Buntings from 11 different breeding sites to explore how individuals from different breeding sites differ in wintering location (chapter 2) and migratory timing (chapter 3). Additionally, I examined differences in migratory behavior between male and females in …


Patterns Of Post-Fire Aspen Seedling Establishment, Growth, And Mortality In The Western United States, Mark Regier Kreider May 2021

Patterns Of Post-Fire Aspen Seedling Establishment, Growth, And Mortality In The Western United States, Mark Regier Kreider

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sexual seedling establishment in aspen is increasingly recognized as an important natural regeneration pathway for the species in the western U.S. However, information on seedling abundance as well as factors influencing aspen sexual regeneration is limited and frequently anecdotal, due to historical assumptions of seedling rarity as well as difficulty identifying sexual seedlings from asexual aspen sucker regeneration. This thesis contributes to the field of aspen seedling ecology in three major ways. Chapter 1 utilizes historical aspen seedling occurrences in the western U.S. and a systematic field survey of 2018 fire footprints to explore patterns and test assumptions of aspen …


The Fate And Cycling Of Nitrogen, Phosphorous, And Trace Heavy Metals In Beaver-Altered Headwater Streams, Desneiges S. Murray May 2021

The Fate And Cycling Of Nitrogen, Phosphorous, And Trace Heavy Metals In Beaver-Altered Headwater Streams, Desneiges S. Murray

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Human land-use can increase the amount of non-point source (NPS) pollution in a stream, negatively affecting ecosystem health and beneficial services provided by an ecosystem. Unfortunately, NPS pollution remains high in many waterbodies. Beaver dams may be a passive, cost-effective strategy for removing NPS pollution in headwater streams because beaver dams slow stream flow and collect sediments. Impounded sediments can change how nutrients and pollutants are cycled in a stream through multiple pathways. In the first part of our study, we investigated whether beaver activity can reduce nitrogen, phosphorous and heavy metals from otherwise traveling downstream. Results suggest beaver ponds …