Digital Commons Network^™

Microbiome Assembly And Function In The Solitary Mason Bee, Osmia Lignaria (Megachilidae), Bailey Crowley

All Graduate Theses and Dissertations, Fall 2023 to Present

Animal-microbe interactions can influence host biology, ecology, and evolution. The assembly and function of microbes found within animal hosts oftentimes depends on which species are involved. Advances in sequencing technologies have permitted the exploration of host-microbe interactions in a variety of animals, including bees. Early research aimed at understanding the microbiomes of social bees, such as honey bees and bumble bees, found that microbes prevent the spoilage of stored pollen, breakdown indigestible nutrients into smaller molecules available for uptake by the host, and also protect the host from pathogens. When environmental stressors, such as increased temperatures, disrupt the microbiome, the …

Rock Glaciers In Utah, Scott Hotaling, Kendall Becker, Matthew Morriss

All Current Publications

Utah’s primary water supply––winter snowpack––is in decline due to climate warming coupled with more precipitation falling as rain instead of snow. As snowpack dwindles, other sources of cold stream water, such as rock glaciers, will become more important. Rock glaciers contain significant volumes of internal ice covered by debris. This internal ice provides cold meltwater to mountain streams, sustaining flows in summer and supporting biodiversity. Rock glaciers are common in Utah’s mountains and are projected to be more stable under climate change than Utah’s snowpack. Thus, rock glaciers are likely to persist in their current form even as snowpack volumes …

Linking Microbial Community Assembly In Flowers With Function Under Diverse Environmental Conditions: A Case Study Involving Erwinia Amylovora, Christopher Skylar Mcdaniel

All Graduate Theses and Dissertations, Fall 2023 to Present

Fire blight, a devastating disease of pome fruit trees caused by the bacterium Erwinia amylovora, can cause millions of dollars in losses for producers each year around the globe. Management approaches that involve use of antibiotics, such as streptomycin, can be effective; although concerns exist over pollinator and crop health when using them regularly. Recently, there have been developments that allow for biological agents such as microbes to curtail fire blight infection. These agents work by competing with Erwinia for resources or space, producing antibacterial compounds, or even killing Erwinia cells on contact. Unfortunately, these agents do not yet …

Tropical Atlantic Temperature And Hydrologic Shifts During The Paleocene-Eocene Thermal Maximum, Chels Howard

All Graduate Theses and Dissertations, Fall 2023 to Present

The Paleocene-Eocene Thermal Maximum (PETM) is a geologic climate event that is studied heavily due to the similarities to anthropogenic climate change. This event occurred approximately 56 million years ago (Ma) and is characterized by a rapid release of carbon into the atmosphere, which resulted in an increase in temperature and a change in global climate events such as changes in patterns of evaporation and precipitation. We see this effect occurring in modern anthropogenic climate change due to the burning of fossil fuels releasing carbon dioxide (CO₂) into the atmosphere. In this study I use elemental data of …

Navigating Roadblocks In Utah's Path Towards Curbing Greenhouse Gas Emissions, Emily K. Fletcher

All Graduate Theses and Dissertations, Fall 2023 to Present

In places where discussions about climate change have become highly political and divided, community groups have attempted to connect rival political parties by focusing on improving air quality. This topic is often less politically charged. The effects of climate change have been disproportionately felt by marginalized communities around the world. In the west side of the Salt Lake Valley, many communities are more likely to experience the negative consequences of a drying lake, a problem that Utah and other regions are currently facing, compared to others in the valley. This research focuses on the individuals who have signed the Utah …

Utahns' Perceptions Of Climate Change And Disaster Vulnerabilities, Mufti Nadimul Quamar Ahmed, Jennifer E. Givens, Peter D. Howe, Jessica D. Ulrich-Schad

Utah People and Environment Poll (UPEP)

Climate change increases the frequency and severity of extreme weather events, making people more vulnerable in a variety of ways^1-2. It is essential to determine if individuals believe they are susceptible to the effects of climate change in order to develop effective adaptation strategies.

Climate change has contributed to extreme weather occurrences in Utah in recent years. For instance, in the summer of 2022, there was a severe or extreme drought in all of Utah's counties³. Health effects of drought vary with intensity⁴ and can cause climate related deaths directly and indirectly, such as by …

Co-Creating Culturally Inclusive Climate Change Programming: A Qualitative Study With Indigenous Populations In Southeast Utah, Bayli R. Hanson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study explores the impact of climate change on underrepresented communities, particularly Indigenous populations in the Colorado Plateau region, and the negative effects on their cultural identities and traditional practices. Despite their knowledge and connection to the land, Indigenous communities are experiencing climate change at a more extreme rate due to their geographical location and the lasting impacts of settler colonialism. The study aims to better understand Indigenous perspectives of climate change, co-create a climate change curriculum with Indigenous populations in southeastern Utah, and apply it to an Indigenous-centric field experience. By incorporating traditional ecological knowledge and Western science practices, …

Opportunities And Challenges For Cooperative Extension Becoming A Major Actor In Climate Change Mitigation And Adaptation, Dakoeta R. Pinto

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Addressing climate change in the United States is an increasingly complex issue that requires social and technological changes throughout the country, which the Cooperative Extension System (Extension) can influence. Based at land-grant universities, their goals are to bring relevant science and innovation to the people of the United States. For a successful low-carbon transition, there are certain elements of society that must be influenced by innovators like Extension. Extension’s historical roots in agriculture prevail today with most of their programming focusing on this sector. However, there is a movement within Extension to expand their programmatic efforts to address more contemporary …

Local And Regional Landscape Characteristics Driving Habitat Selection By Greater Sage-Grouse Along A Fragmented Range Margin, Aidan T. Beers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In response to ongoing landscape change, wildlife species are likely to respond in varied ways. By studying habitat specialists, we are able to better understand the most likely ways in which the denizens of threatened ecosystems will react to those changes. Among the most threatened ecosystem types in North America are sagebrush ecosystems of the Intermountain West, where one of its most well-known residents, greater sage grouse (hereafter, “sage-grouse), have lost more than 50% of their habitat due to fire, invasive species, climate change, encroachment by coniferous forests and avian predators using it, and human-caused landscape conversion. Sage-grouse rely on …

The Effects Of Recent Climate Change On Spring Phenology, With A Special Focus On Patterns Of Bee Foraging, Michael Stemkovski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The date on which plants flower and on which bees begin to pollinate varies year-to-year depending on differences in weather. This seasonal timing is known as phenology, and it is already clear that climate change has pushed the spring phenology of many species earlier by increasing temperatures. This is particularly clear in flowering plants, but studying how and why the phenology of pollinators is shifting is more difficult. Most flowering plants rely on pollinators such as bees for their reproduction, and most bees rely on flowers for their sustenance, so bee and flower phenology has to overlap for the crucial …

Getting The Dirt On Phosphorus Pollution In Mountain Lakes: Are Rising Soil Temperatures Contributing To Eutrophication In Mountain Watersheds?, Gordon O. Gianniny

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mountain watersheds provide a critical supply of clean water to millions of people around the world. In recent years, evidence of a concerning trend has emerged in these watersheds: rising phosphorus (P) concentrations. P often acts as the limiting nutrient in mountain lake ecosystems, so increasing P availability in mountain lakes and streams has the potential to drastically increase algal growth in these systems. In extreme cases, increasing mountain lake P concentrations may even cause harmful algal blooms that degrade downstream water quality. While the implications of rising P concentrations in mountain lakes are serious, the cause driving this widespread …

Responses Of Extreme Discharge To Changes In Surface-Air And Dewpoint Temperatures In Utah: Seasonality And Mechanisms, Timothy E. Wright, Jacob Stuivenvolt-Allen, Grace Affram, Nahid A. Hasan, Cody Ratterman, Wei Zhang

Plants, Soils, and Climate Faculty Publications

The changes in stream discharge extremes due to temperature and seasonality are key metrics in assessing the effects of climate change on the hydrological cycle. While scaling is commonly applied to temperature and precipitation due to the physical connections between temperature and moisture (i.e., Clausius–Clapeyron), the scaling rate of stream discharge extremes to air and dewpoint temperatures has not been evaluated. To address this challenge, we assess the scaling rates between stream discharge and air temperature and between stream discharge and dewpoint temperature in Utah using a well-designed statistical framework. While there are deviations from the Clausius–Clapeyron (CC) relationship in …

Sea-Ice Conditions Predict Polar Bear Land Use Around Military Installations In Alaska, Eric V. Regehr, Kristin L. Laidre, Todd C. Atwood, Harry L. Stern, Benjamin Cohen

Human–Wildlife Interactions

Polar bears (Ursus maritimus) are threatened by sea-ice loss due to climate change, which is concurrently opening the Arctic to natural resource extraction and a broader scope of national security responsibilities. Mitigating the risk of human–bear conflicts is an emerging challenge as many polar bears spend longer ice-free summers on land where they have limited access to food and come into more frequent contact with people. We investigated a suite of physical and ecological variables that influence the timing of polar bear arrival on, and departure from, land using remote-sensing data on sea-ice extent and satellite telemetry data …

Reversing The Gaze: Using Indigenous And Western Media Frames To Compare Coverage Of Climate Change And Indigenous Peoples In The News Media, Eric Wilkes

Fall Student Research Symposium 2022

The news media acts as an important conduit for shaping societal views of the socio-politics of climate change. While climate change will indeed affect everyone, it will not affect everyone equally. Indigenous peoples are among the populations whose well-being is threatened the most by climate change. International scholarship finds it is not uncommon for Indigenous cultures, communities, and perspectives to be underrepresented and misrepresented in Western climate change media. Research also indicates that fair Indigenous representation occurs when Indigenous peoples are the authors of news articles themselves. We performed a comparative content analysis of media coverage of climate change, environmental …

Modeling Plant Migration In A Varying Landscape, Seth Corbridge

Fall Student Research Symposium 2022

It is important to predict how plants will migrate under the changing conditions associated with climate change. In particular, finding instances where plants migrate quickly will help in predicting which plant species are in danger of being outpaced by climate change. Many existing models for plant migration assume a homogeneous landscape, however this is not always fully realistic. This project considers a model incorporating landscape heterogeneity for modeling plant migration. By forming a landscape of varying patches of high and low motilities, it is shown how a varying landscape can lead to increased migration rates in some cases when compared …

Editorial: Mammalian Responses To Climate Change: From Organisms To Communities, Johan T. Du Toit, Robyn S. Hetem, M. Denise Dearing

Wildland Resources Faculty Publications

Mammals have displayed spectacular evolutionary success ever since an asteroid impact caused the Cretaceous-Tertiary extinction event ~66 million years ago, when the non-avian dinosaurs disappeared. Now another mass extinction event is underway because of another major planetary disturbance, but this time it is directly caused by just one over-achieving species among all those mammals: Homo sapiens.

An Evaluation Of Landscape, Climate, And Management Impacts On Bumble Bees (Hymenoptera: Apidae: Bombus) In Agroecosystems, Morgan Elizabeth Christman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bumble bees play pivotal roles in pollinating wild and cultivated plant communities. Unfortunately, bumble bee populations are declining due to disturbances such as landscape conversion and climate change. Additionally, traps used to monitor pest insect populations often capture bumble bees, leading to a concern that trap captures increase bumble bee mortality. First, I studied bumble bee communities based on land cover and weather variables in agricultural fields in Utah. Bumble bee communities were more diverse in agricultural fields with more agricultural land in the surrounding area, low temperatures, and high humidity during the growing season, and less diverse in fields …

Reversing The Gaze: Using Indigenous And Western Worldviews To Compare Coverage Of Climate Change And Indigenous Peoples In The News Media, Gina Mccrackin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The news media acts as an important conduit for shaping societal views of the socio-politics of climate change. While climate change will indeed affect everyone, it will not affect everyone equally. Indigenous peoples are among the populations whose well-being is threatened the most by climate change. International scholarship finds it is not uncommon for Indigenous cultures, communities, and perspectives to be underrepresented and misrepresented in Western climate change media. Research also indicates that fair Indigenous representation occurs when Indigenous peoples are the authors of news articles themselves. We evaluated the differences in discussions of climate change and environmental issues …

Hidden Mechanisms Of Climate Impacts In Western Forests: Integrating Theory And Observation For Climate Adaptation, Sara J. Germain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fire, insects, and disease are necessary components of forest ecosystems. Yet, climate change is intensifying these tree stressors and creating new interactions that threaten forest survival. This dissertation combined field observations with statistical predictions of changing disturbances in western forests to identify 1) how conventional models may underestimate future forest loss, and 2) how positive relationships between trees may be exploited by managers to prevent forest loss.

In Chapter II, I tested whether increasingly extreme weather with climate change increases Pacific yew extinction risk. I found that conventional modeling methods underestimated local extinction risk because trees were adapted to a …

Impacts Of The Changing Pacific On North American Drought, Atmospheric Rivers, And Explosive Cyclones, Jacob Stuivenvolt-Allen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The impacts of specific weather events can vary greatly from year to year. Much of these impacts depend heavily on the frequency of impactful weather which is constrained by the state of the climate system each year. This research focuses largely on the impacts that climate oscillations from year-to-year or even from decade-to-decade have on the frequency of impactful weather. There are numerous examples of impactful weather that impact North America, but this work focuses on drought in the western United States, atmospheric rivers in Northern California and rapidly developing winter storms along the east coast. While seemingly disparate events, …

Effective Conservation Of Desert Riverscapes Requires Protection And Rehabilitation Of In-Stream Flows With Rehabilitation Approaches Tailored To Water Availability, Casey A. Pennock, Phaedra Budy, William W. Macfarlane

Watershed Sciences Faculty Publications

Desert riverscape rehabilitation practitioners must contend with compounding effects of increasing human water demand, persistent drought, non-native species establishment, and climate change, which further stress desert riverine ecosystems such as rivers in the Colorado River basin, United States. Herein, we provide our perspective on the importance of natural flows, large floods in particular, for successful conservation and rehabilitation of riverscapes. We present ideas developed from our experience with rehabilitation projects across multiple desert tributary rivers with varying levels of habitat degradation and water abstraction. We propose spatially extensive measures such as protection of in-stream flows, tailoring rehabilitation efforts to available …

The Impacts Of Increased Precipitation Intensity On Dryland Ecosystems In The Western United States, Martin C. Holdrege

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As the atmosphere warms, precipitation events become larger, but less frequent. Such increases in precipitation intensity are expected regardless of changes in total annual precipitation. Despite strong evidence for increases in precipitation intensity, disagreement exists regarding how these changes will impact plants, and studies are lacking in many types of ecosystems. This dissertation addresses how increased precipitation intensity affects soil water availability, and how plants respond to any such changes. I address this question in the context of big sagebrush ecosystems and dryland winter wheat agriculture, which are both environments that can be sensitive to changes in water availability. Results …

Hydrological Intensification Will Increase The Complexity Of Water Resource Management, Darren L. Ficklin, Sarah E. Null, John T. Abatzoglou, Kimberly A. Novick, Daniel T. Myers

Watershed Sciences Faculty Publications

Global warming intensifies the hydrological cycle by altering the rate of water fluxes to and from the terrestrial surface, resulting in an increase in extreme precipitation events and longer dry spells. Prior hydrological intensification work has largely focused on precipitation without joint consideration of evaporative demand changes and how plants respond to these changes. Informed by state-of-the-art climate models, we examine projected changes in hydrological intensification and its role in complicating water resources management using a framework that accounts for precipitation surplus and evaporative demand. Using a metric that combines the difference between daily precipitation and daily evaporative demand (surplus …

Climate Effects On Black Spruce And Trembling Aspen Productivity In Natural Origin Mixed Stands, Mahadev Sharma

Aspen Bibliography

Forest managers need site productivity estimates for tree species growing in mixed stands. Models developed in the past are generally for pure stands and don’t factor in the effects of climate change on site productivity. Therefore, site index (SI) models were developed for black spruce (Picea mariana Mill. B.S.P.) and trembling aspen (Populus tremuloides Michx.) trees grown in natural origin mixed stands. For this, 186 trees (93 black spruce and trembling aspen each) were sampled from 31 even-aged natural mixed stands (sites) (3 trees/species/site) across Ontario, Canada. Stand height growth models were developed by incorporating climate variables during …

Wind And Fire: Rapid Shifts In Tree Community Composition Following Multiple Disturbances In The Southern Boreal Forest, Elias Anoszko, Lee E. Frelich, Roy L. Rich, Peter B. Reich

Aspen Bibliography

Under a warming climate, the southern boreal forest of North America is expected to see a doubling in fire frequency and potential for increased wind disturbance over the next century. Although boreal forests are often considered fire-adapted, projected increases in disturbance frequency will likely result in novel combinations of disturbances with severities and impacts on community composition outside historic norms. Using a network of repeatedly measured vegetation monitoring plots, we followed changes in tree community composition in areas of the Boundary Waters Canoe Area Wilderness (BWCAW), in Minnesota, USA, experiencing disturbances ranging from severe windstorms or wildfires to areas affected …

Melting Arctic Ice Exposes Possible Conflict For Us, China, Russia, Madeleine Alder

Research on Capitol Hill

USU senior Maddie, a Salt Lake City native, is an Honors student, Peak Summer Research Fellow, and USU Institute of Land, Water and Air intern. She studies Political Science. Maddie’s research dissects how rising temperatures and the resulting polar ice caps on our planet might impact international relations for the US. The opening of additional shipping lanes in previously-frozen waters could cause conflict between key actors. Maddie has been involved in research for nearly all of her undergrad degree, and says, “I love learning and I get excited to discover new connections between topics I am interested in. I like …

Precipitation Is A Strong Predictor Of Airborne Ammonia Levels., Bridger Jorgensen, Casey Olson, Connor Snow

Research on Capitol Hill

USU senior Connor has lived in the Uintah Basin all his life and studies kinesiology. Senior Casey, a Cache Valley native, studies climate science and works at the Utah Climate Center. Junior Bridger, also of Cache Valley, studies nutrition science. They led and funded this project through a student grant. Casey was alarmed by the ammonia data he was collecting at the Climate Center. “I immediately began to wonder how this issue would evolve over the coming decades.” The three teamed up to take a look at how Logan’s record-breaking amount of ammonia in our air is impacting those who …

Bottom-Up Drivers Of Future Fire Regimes In Western Boreal North America, Adrianna C. Foster, Jacquelyn K. Shuman, Brendan M. Rogers, Xanthe J. Walker, Michelle C. Mack, Laura L. Bourgeau-Chavez, Sander Veraverbeke, Scott J. Goetz

Aspen Bibliography

Forest characteristics, structure, and dynamics within the North American boreal region are heavily influenced by wildfire intensity, severity, and frequency. Increasing temperatures are likely to result in drier conditions and longer fire seasons, potentially leading to more intense and frequent fires. However, an increase in deciduous forest cover is also predicted across the region, potentially decreasing flammability. In this study, we use an individual tree-based forest model to test bottom-up (i.e. fuels) vs top-down (i.e. climate) controls on fire activity and project future forest and wildfire dynamics. The University of Virginia Forest Model Enhanced is an individual tree-based forest model …

Identifying Conifer Tree Vs. Deciduous Shrub And Tree Regeneration Trajectories In A Space-For-Time Boreal Peatland Fire Chronosequence Using Multispectral Lidar, Humaira Enayetullah, Laura Chasmer, Christopher Hopkinson, Dan Thompson, Danielle Cobbaert

Aspen Bibliography

Wildland fires and anthropogenic disturbances can cause changes in vegetation species composition and structure in boreal peatlands. These could potentially alter regeneration trajectories following severe fire or through cumulative impacts of climate-mediated drying, fire, and/or anthropogenic disturbance. We used lidar-derived point cloud metrics, and site-specific locational attributes to assess trajectories of post-disturbance vegetation regeneration in boreal peatlands south of Fort McMurray, Alberta, Canada using a space-for-time-chronosequence. The objectives were to (a) develop methods to identify conifer trees vs. deciduous shrubs and trees using multi-spectral lidar data, (b) quantify the proportional coverage of shrubs and trees to determine environmental conditions driving …

New Research And Wild Horse And Burro Management, David Jenkins

Human–Wildlife Interactions

In the United States, the Wild Free-Roaming Horses and Burros Act (WFRHBA) gave the Bureau of Land Management (BLM) and the U.S. Forest Service the statutory obligation to manage and protect free-roaming equids (i.e., wild horses [Equus ferus] and burros [E. asinus]) on designated management areas on public land. The WFRHBA was intended to ensure that wild horses and burros on the public lands exist in self-sustaining herds in perpetuity, alongside other congressionally mandated, multiple uses of public lands. The BLM recently published a strategic research plan for their wild horse and burro program. The research …