Theses and Dissertations at Montana State University (MSU)
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Item Patch habitat contributions to biodiversity, ecosystem services, and crop production in the Northern Great Plains(Montana State University - Bozeman, College of Agriculture, 2023) Duff, Hannah Katherine; Chairperson, Graduate Committee: Bruce D. Maxwell; This is a manuscript style paper that includes co-authored chapters.In response to global calls for sustainable food production and biodiversity conservation, we explored the potential of conserving small non-crop patch habitats, or ecological refugia, to meet food production and conservation objectives within agroecosystems. This dissertation considered multi-objective outcomes of conserving ecological refugia within dryland grain production systems in the Northern Great Plains (NGP) that included agronomic, ecological, and economic tradeoffs, and policy implications. First, we proposed the union of production oriented and ecologically oriented agriculture within a precision agroecology framework. We advocated for the merger of precision agriculture technology and agroecological principles to transform food systems. First, we explored the potential to incorporate biodiversity into crop fields using precision conservation to conserve low-yield areas as patch habitat and manage for sub-field variation. Second, we found that small ecological refugia increased plant and arthropod diversity, provided ecosystem service tradeoffs, and enhanced crop yield, but not crop quality in three dryland grain production systems in the NGP. Third, we found that local biodiversity response to landscape context was scale-dependent, and that correlations between landscape variables and local biodiversity were lowest at the most distant extent (< or = 5km from the ecological refuge). Partial R-squared values were highest when both local and landscape variables were included, and when composition and configuration variables were included in models predicting local biodiversity. These results suggested that local conservation efforts should be coordinated with landscape-level efforts to enhance biodiversity and ecosystem service provision across agricultural landscapes. Last, we found that removing low-yielding portions of crop fields from production could provide positive returns on investment to farmers but profitability depended on the size of the patch removed, harvest year, grain price received, potential yield gain associated with ecosystem services, and government conservation program incentives. Additional noneconomic policy levers may be needed to incentivize adoption of on-farm conservation practices. Looking forward, ecological refugia have the potential to host biodiversity, increase agroecosystem functioning, and benefit crop production. Future research should investigate site-specific practices for patch habitat conservation, determine effective incentives for on-farm conservation, and coordinate landscape-scale efforts to create and connect agroecological landscapes.Item The role of terpenoids and phenolics in controlling ecological impacts of hemlock wooly adelgid in the great smoky mountains national park(Montana State University, 2021) Branum, Emily Renaee; Chairperson, Graduate Committee: Scott PowellThe hemlock woolly adelgid (Adelges tsugae) is an invasive pest in the eastern United States where they have been colonizing and feeding on eastern hemlock oleoresin, initiating death and stand decline. Eastern hemlock stand reductions are important in the Great Smoky Mountains National Park because they host a notoriously biodiverse ecosystem, which is popular among tourists and economically supports the neighboring communities of Pigeon Forge and Gatlinburg, Tennessee. Rapid decline of eastern hemlock and their associated microclimates affect many abiotic and biotic aspects of the surrounding ecosystem. Although dependent on abiotic factors and metabolically costly to produce, terpenoids and phenolics have repellency potential in sufficient concentrations to prevent the loss of eastern hemlock and their associated ecological impacts. Therefore, I conducted a comprehensive, interpretive literature review to assess which terpenoids and phenolics are released after hemlock woolly adelgid herbivory, the extent to which they are produced, and if they lead to herbivory reductions. That knowledge is then related to ecological impacts caused by their release. Although not actually performed, I present sampling and analysis methods to achieve a representative terpenoid and phenolic profile followed by probable results, a discussion of current and potential management strategies, and subjects of future study. Overall, my paper is informative in nature and could provide insight and direction in the development of resistance-breeding, mitigation, and conservation programs. Regardless of which strategy is chosen, adequate monitoring, management, and restoration is needed to preserve eastern hemlock. Otherwise, the hemlock woolly adelgid population will continue to expand, negatively affect hemlocks, and degrade the Great Smoky Mountain National Park ecosystem.Item Linking substrate organic matter and water quality to invertebrate and fish populations within a constructed wetland treatment system(Montana State University, 2020) Sees, Mark Daniel; Chairperson, Graduate Committee: William KleindlThe Orlando Easterly Wetlands is a highly engineered and managed free surface flow constructed wetland treatment system that was constructed for the expressed purpose of removing nitrogen and phosphorus from municipal reclaimed wastewater. The system has been in operation since 1987 and is managed and maintained for water quality. Through the 33 years of operation, the system has accumulated tremendous amounts of organic matter through natural wetland processes. However, this organic matter has caused significant short-circuiting of water flow ultimately leading to the need for removal. Removal of the organics is expensive and time-consuming and results in a complete renovation of the wetland marshes. These renovation projects effectively remove the organics along with the plants and wildlife species that inhabit a given project area. My paper aims to link water quality, accreted organic matter, and wildlife diversity and abundance. I theorized that biodiversity within the system is influenced and driven by the constant input of dissolved nutrients and the associated organic matter accretion. Through substrate samplers, dip netting, and minnow traps, aquatic biota was sampled and correlated with water quality indicators such as chlorophyll-a, carbonaceous biochemical oxygen demand, ammonia, ortho phosphate, total kjedahl nitrogen, total nitrogen, and total phosphorus along with the depths of organic matter. The abundance of macroinvertebrates was strongly correlated with carbonaceous biochemical oxygen demand (r2=0.91) and total nitrogen (r2=0.88). Ammonia displayed a moderate positive correlation and depths of the accreted organic matter were weakly correlated. The presence and abundance of larger more mobile aquatic species were moderately correlated with levels of chlorophyll-a (r2=0.702). OP and TP showed significant negative correlations (r2 = -0.619, -0.628), respectively. Suggesting that as OP and TP concentrations decrease abundance increases. I also document the rapid recolonization of invertebrates within newly renovated marshes in the Orlando Easterly Wetlands and how this system provides outstanding biodiversity.Item Sierran mixed conifer forest wildfires: a biodiversity comparison between active and passive timber land management(Montana State University - Bozeman, College of Agriculture, 2019) Dalby, Caitlin M.; Chairperson, Graduate Committee: William KleindlThe mixed conifer forests of the Northern Sierras have great value in their biodiversity. Timber land management in this region varies by land owner and their objectives, including timber harvest and conservation. An increase in annual wildfires each year indicates a need to understand how different silvicultural strategies before and after fires affect the overall ecosystem biodiversity. Ecosystem functions and services can be affected by many factors involving anthropogenic activities in combination with fires. The aim of this study was to determine to what degree active (private timber company) and passive (United States Forest Service) management after a wildfire may affect plant biodiversity, and to compare those silvicultural approaches to active and passive pre-fire management. The study takes place within the vicinity of the 2012 Chips fire burn scar in Plumas County, California. Using tree canopy and plant species percent cover, in addition to presence and absence data, within frames and nested frames along 50 meter transects, statistical analyses revealed little significant difference between active and passive management. Analysis from data collected in this study concluded that tree canopy cover is significantly different under active post-fire management than under passive post-fire management and pre-fire conditions. There was not a significant difference in understory biodiversity (richness and evenness) among the four treatments. Dissimilarity in plant species composition was significant among the burned and unburned treatments, as well as between the two differently managed burned treatments. While the treatments were significantly dissimilar, there was not enough data collected to account for the high degree of variability seen in the data and so further data collection and analyses across multiple spatial and temporal scales would give better insight into the differences in biodiversity between treatments.Item Geomorphology, biodiversity and ecosystem function, and food web dynamics in large riverscapes(Montana State University - Bozeman, College of Letters & Science, 2021) Scholl, Eric Arthur; Chairperson, Graduate Committee: Wyatt F. Cross; This is a manuscript style paper that includes co-authored chapters.Humans have transformed the Earth's surface so extensively that we now play a dominant role in regulating geomorphological processes around the world. These effects are particularly prevalent in large rivers, which despite their high biophysical complexity, face widespread habitat alteration and simplification. The way species respond to such changes will unquestionably impact the structure and function of ecosystems, with cascading effects on numerous goods and services they provide. Consequently, efforts to understand how the physical habitat template shapes the structure and function of larger river ecosystems are critically needed to predict how future perturbations will impact these imperiled and iconic environments. My dissertation blends approaches from the physical and ecological sciences to uncover connections between the geophysical habitat template, biodiversity and ecosystem function, and the dynamics of food webs in large riverscapes. My questions were: 1) what are the spatial patterns and potential drivers of riverbed habitat, and how do they relate to process domain structures in large rivers? 2) how does the geophysical habitat template influence connections between invertebrate diversity and secondary production? and 3) how are trophic interactions supporting the federally endangered Pallid Sturgeon (Scaphirhynchus albus) shaped by the geophysical habitat template? I found consistent patterns of nested patchiness in riverbed substrate, indicating that multiple factors operating at different scales influence spatial patterns of substrate in the Missouri and Yellowstone Rivers. Invertebrate assemblages were tied to attributes of the geophysical habitat template, with strong relationships between large sediments and diversity. Invertebrate diversity, in turn, was positively related to secondary production, with the most diverse assemblages found in secondary production 'hotspots'. Finally, I found a general relationship between habitat diversity and trophic interaction strengths supporting Pallid Sturgeon, with geophysically diverse areas containing much weaker, and thus potentially stabilizing, interactions than homogenous areas. Additionally, habitat characteristics, such as sediment size, intensified these effects. Together, the chapters of my dissertation broadly highlight the role of nature's stage in governing patterns in biodiversity, secondary production, and trophic interactions across large and dynamic riverscapes, and provide empirical insights for guiding future management and conservation of large rivers in an increasingly simplified world.Item Wetland biodiversity in Grand Teton National Park(Montana State University - Bozeman, College of Letters & Science, 2022) Levandowski, Mary Lynn; Chairperson, Graduate Committee: Andrea Litt; Andrea R. Litt was a co-author of the article, 'Spatial and temporal isolation and size of wetlands influence richness and functional composition of aquatic macroinvertebrates' which is contained within this thesis.; Andrea R. Litt, Megan F. McKenna, Shan Burson and Kristin L. Legg were co-authors of the article, 'Multi-method biodiversity assessments from wetlands in Grand Teton National Park' in the journal 'Ecological indicators' which is contained within this thesis.Freshwater wetlands support high biodiversity, yet many wetlands are subject to shifts in precipitation and temperature under projected climate patterns. These changes can alter wetland hydrological regimes, potentially leading to longer or more frequent dry periods, with effects that differ among taxa. In this thesis we aim to build on the understanding about biodiversity in wetlands and how these species may be affected by climate change, in hopes of providing information for land management. To accomplish these goals, we first focused on macroinvertebrates, a group that employs diverse strategies for surviving wetland drying. We explored the roles of wetland size, spatial isolation, and temporal isolation on macroinvertebrate richness and community composition. In summer 2018, we collected macroinvertebrates from 18 wetlands in Grand Teton National Park. We found macroinvertebrate family richness increased with wetland depth and slower rates of drying. We also found the interaction between spatial and temporal isolation explained the most variation in community composition for all the life history strategies we examined. Second, we explored the utility of different automated tools to monitor biodiversity in wetlands. In 2017, we placed wildlife cameras, as well as acoustic (audible and ultrasonic) recorders at 4 permanent wetlands in Grand Teton National Park for a week in June and August; we also completed a visual survey during each of these time intervals. We compared the number and type of species detected by each method over the summer to evaluate the effectiveness of each method for monitoring. Using wildlife cameras, in addition to visual surveys, increased the observation time at surveyed wetlands, captured complementary species, and recorded dynamics in the water level during the summer. These two chapters provide insights about how changes resulting from increased drying may affect one of the most biodiverse taxa and offer methods that allow monitoring of many taxa simultaneously.Item Population structure, gene flow, and genetic diversity of Rocky Mountain bighorn sheep informed by genomic analysis(Montana State University - Bozeman, College of Agriculture, 2020) Flesch, Elizabeth Pearl; Chairperson, Graduate Committee: Jennifer Thomson; Jay J. Rotella, Jennifer M. Thomson, Tabitha A. Graves and Robert A. Garrott were co-authors of the article, 'Evaluating sample size to estimate genetic management metrics in the genomics era' in the journal 'Molecular ecology resources ' which is contained within this dissertation.; Tabitha A. Graves, Jennifer M. Thomson, Kelly M. Proffitt, P.J. White, Thomas R. Stephenson and Robert A. Garrott were co-authors of the article, 'Evaluating wildlife translocations using genomics: a bighorn sheep case study' in the journal 'Ecology and evolution' which is contained within this dissertation.; Tabitha A. Graves, Jennifer M. Thomson, Kelly M. Proffitt and Robert A. Garrott were co-authors of the article, 'Genetic diversity of bighorn sheep population is associated with dispersal, augmentation, and bottlenecks' submitted to the journal 'Biological conservation' which is contained within this dissertation.This dissertation evaluated the genomics of bighorn sheep (Ovis canadensis) herds across the Rocky Mountain West to determine optimal sample size for estimating kinship within and between populations (Chapter Two), to detect gene flow due to natural dispersal and translocations (Chapter Three), and to evaluate the correlation between genetic diversity and influences on population size (Chapter Four). To date, wildlife managers have moved many bighorn sheep across the Rocky Mountain West in an effort to provide new genetic diversity to isolated herds. However, little is known about the genetics of these herds and the real impacts of translocations. To learn how populations have been impacted by these management actions, we genotyped 511 bighorn sheep from multiple populations using a new cutting-edge genomic research technique, the Illumina Ovine High Density array, which contained about 24,000 to 30,000 single nucleotide polymorphisms informative for Rocky Mountain bighorn sheep. First, we determined that a sample size of 20 to 25 bighorn sheep was adequate for assessment of intra- and interpopulation kinship. In addition, we concluded that a universal sample size rule for all wild populations or genetic marker types may not be able to sufficiently address the complexities that impact genomic kinship estimates. Secondly, we synthesized genomic evidence across multiple analyses to evaluate 24 different translocation events; we detected eight successful reintroductions and five successful augmentations. One native population founded most of the examined reintroduced herds, suggesting that environmental conditions did not need to match for populations to persist following reintroduction. Finally, we determined that influences on population size over time were correlated with genetic diversity. Gene flow variables, including unassisted connectivity and animals contributed in augmentations, were more important predictors than historic minimum population size and origin (i.e. native vs. reintroduced). This hypothesis-based research approach will give wildlife managers additional biological insight to help inform various management options for bighorn sheep restoration and conservation.Item Integrating cover crop mixtures in the northern Great Plains: an ecological assessment on crop productivity, biodiversity, and temperature and moisture conditions(Montana State University - Bozeman, College of Agriculture, 2020) DuPre, Mary Ellyn; Chairperson, Graduate Committee: Fabian D. Menalled and Tim F. SeipelCropping systems can impact crop productivity and functioning of biodiversity in the Northern Great Plains, a region heavily reliant on low diversity crop rotations and off-farm inputs, and a region predicted to experience warmer and drier climate scenarios by mid-century. In three complementary studies, I compared the impacts of cover crop mixtures and termination methods on crop productivity and three forms of the associated biodiversity (weeds, soil fungi, and ground beetles), under varying temperature and soil moisture conditions. First, I assessed the impacts of the presence (cover crops and fallow) and composition (cover crop mixtures) of cover crops, termination methods (herbicide, cattle-grazing, and haying), as a function of temperature and soil moisture conditions on crop yields, and weed communities. A 5-species, early-spring mixture generated cooler temperatures, produced more biomass, and suppressed weed biomass under warmer and drier conditions, compared to summer fallow and the 7-species, mid-spring mixture. However, lower soil moisture and subsequent reduced grain yields following the mixtures, especially under warmer and drier conditions, suggests that continuously rotating wheat with mixtures may not be the optimal method to diversify small-grain cropping systems. Second, I assessed the impacts of the presence and composition of cover crops, termination methods and temperature and soil moisture conditions on fungal communities. The early-season cover crop mixture reduced plant pathogen abundance and enhanced AM fungal richness in both the soil and subsequent wheat root crop. The enhancement of beneficial fungi and fewer plant pathogens may be a proxy to better support ecosystem services through the use of cover crop mixtures. Third, I compared ground beetle communities among cover crops treatments and termination methods. Ground beetle activity density was not impacted by termination methods and was greatest in the early-season mixture at the beginning of the growing season and in summer fallow at the end of the growing season, while the mid-season mixture peaked in the middle. Ground beetle diversity peaked in the middle and differed in community composition earlier in the growing season. These results indicate that cover crop mixtures can act as an ecological filter to ground beetle communities to better support pest regulation. Overall, these studies indicate that cover crop mixtures can support crop productivity and the associated biodiversity with changes to temperature and soil moisture, although, with agronomic and ecological trade-offs.Item Implementing a citizen science project in a 9-12 high school science classroom(Montana State University - Bozeman, College of Letters & Science, 2019) Langager, Paula Marie; Chairperson, Graduate Committee: Walter WoolbaughThis classroom action research (AR) project explored the impacts of project-based learning on high school students critical thinking, decision-making, data collection and data analysis skills through the implementation of a citizen science project. AP® Environmental Science (APES) students co-developed a citizen science project that explored their local schoolyard biodiversity by designing and researching their own scientific investigative question. An evaluation of students changes in science self-efficacy, and attitudes toward science research and specific science tasks was tracked throughout the project. Pre- and post-Likert surveys, open-ended questions, field journals, focus group interviews, and a biological solutions science poster were employed as data collection tools. A mixed methodology (qualitative and quantitative) was used to analyze the data. These results showed that students made reasonable gains in data collection and analysis skills, critical thinking and decision-making abilities. Noticeable improvements were detected in student attitudes toward science and science self-efficacy. A discernable change was observed in the student's overall data and data analysis skills related to a field study.Item Distributions, abundances, and movements of small, nongame fishes in a large Great Plains river network(Montana State University - Bozeman, College of Letters & Science, 2019) Duncan, Michael Bennett; Chairperson, Graduate Committee: Alexander V. ZaleThe Yellowstone River is the longest unimpounded river in the conterminous United States and was thought to support a diverse fish assemblage; however, comprehensive data on the small nongame fish assemblage was lacking. I evaluated the sampling methods often used to capture small-bodied fishes in the channel margins of large Great Plains rivers, determined the distributions and abundances of these fishes in the Yellowstone River, characterized the movements of selected native cyprinids between the Yellowstone River and its tributaries, and assessed assemblage differences between the Yellowstone and Missouri rivers. Catch-per-unit-effort, species richness, and ranges of total lengths were greater in fyke net catches than in seine catches. Forty-two species (24 native and 18 nonnative) were captured in fyke nets in the lower Yellowstone River. Emerald Shiners Notropis atherinoides, Western Silvery Minnows Hybognathus argyritis, Flathead Chubs Platygobio gracilis, Sand Shiners Notropis stramineus, and Longnose Dace Rhinichthys cataractae composed nearly 94% of fyke net catch. Sturgeon Chubs Macrhybopsis gelida, Channel Catfish Ictalurus punctatus, Flathead Chubs, Stonecats Noturus flavus, and Sicklefin Chubs Macrhybopsis meeki composed 89% of the otter trawl catch. Sicklefin Chubs were captured as far as 18 river kilometers upstream of Glendive, Montana; Sturgeon Chubs were captured as far upstream as the Tongue River confluence. Otolith microchemistry analysis revealed that 69% of Western Silvery Minnows, 65% of Flathead Chubs, and 42% of Sand Shiners moved between main-stem and tributary habitats. The timing, frequencies, and patterns of movements varied among species. In my comparison of the Yellowstone and Missouri river fish assemblages, native and nonnative species richness were highest in Yellowstone River fyke net catches but proliferation of nonnative species was low. Total CPUE was highest in the Yellowstone River (median = 152 fish/net night), intermediate in the Missouri River below the Yellowstone River confluence (44 fish/net night), and lowest in the Missouri River above the confluence (21 fish/net night). Collectively, these studies provide a better understanding of the biotic and abiotic factors that help influence the distributions, abundances, and diversity of life-history strategies of small, nongame fish in Great Plains rivers.