Theses and Dissertations at Montana State University (MSU)
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Item Pollinator conservation and restoration in semi-natural ecosystems(Montana State University - Bozeman, College of Letters & Science, 2022) Glenny, William Robb; Chairperson, Graduate Committee: Laura Burkle; This is a manuscript style paper that includes co-authored chapters.Semi-natural ecosystems are areas with biological and physical characteristics that resemble natural ecosystems but are also affected by anthropogenic disturbances. Semi-natural ecosystems are also areas with high insect pollinator diversity. Land management actions within semi-natural ecosystems may therefore be important to counteract future declines of insect pollinators. However, current restoration strategies for insect pollinator communities are based on evidence from agricultural ecosystems, which have frequent human interventions to ensure plant success, neglect the importance of nesting materials, and primarily benefit generalist species. To inform management actions for the conservation and restoration of insect pollinators in semi- natural ecosystems, I (1) synthesized the current understanding of the effects of common land management actions on insect pollinators on public lands in the US, (2) identified habitat characteristics which structure the taxonomic and functional diversity of bee communities, (3) evaluated the strength of influence of mechanisms associated with diet breadth across groups of bee species and (4) designed a conceptual model which can be used to select flowering plant species to provide food resources for bee communities in semi-natural ecosystems. Management actions that increase the abundance of floral and nesting resources to support bee species from different functional groups are required to conserve and restore insect pollinator communities in semi-natural ecosystems. I found that (1) management actions have positive, neutral, and negative effects on insect pollinators, but research trends vary depending on the taxon and habitat type, (2) the taxonomic and functional diversity of bee communities are structured by the abundance of both floral and nesting resources, (3) patterns of abundance across space and time have a more positive effect on the diet breadth of bumble bee species compared to non- bumble bee species, and (4) wildflower species that receive a high visitation rate and richness, occupy functionally important positions within bee-flower interaction networks, and are spatially and temporally widespread are important to provide bee communities with food resources in semi-natural ecosystems. These wildflower species may be particularly important to include within seed mixes to revegetate semi-natural ecosystems and provide food resources for insect pollinators.Item Bee and butterfly communities in roadside habitats: identifying patterns, protecting monarchs, and informing management(Montana State University - Bozeman, College of Letters & Science, 2023) Meinzen, Thomas Claasen; Chairperson, Graduate Committee: Diane M. DebinskiInsect pollinators play a critical role in our natural and agricultural ecosystems. With global pollinator declines and habitat loss, attention has turned to roadside right-of-way lands (ROWs) as potential areas for supporting pollinator populations. Although many roadsides host flowering plants, understanding whether--and under what circumstances--roadsides actually benefit pollinator populations is critical for good conservation decision-making. Through a literature review, we found that pollinator population data (e.g., birth and death rates) are lacking to assess whether roadsides are a source or sink for pollinator populations. However, conscientious management practices, including reduced, well-timed mowing, selective, targeted spraying, and well-placed native plantings can improve roadsides' potential to support robust pollinator populations. Identifying roadside habitat for diverse pollinator communities and imperiled species is essential to prioritize pollinator-focused management practices across ROW systems. To support efforts to conserve monarch butterflies (Danaus plexippus), we surveyed 1,465 km (910 miles) of southern Idaho highways, mapping 1,363 patches of showy milkweed (Asclepias speciosa), the monarch's host plant. Roadside milkweed often bordered irrigated fields and crops; water availability may best explain its distribution. Existing statewide milkweed models (Svancara et al., 2019) did not effectively predict milkweed distribution in ROWs, suggesting the importance of roadside-specific factors, such as ROW management and disturbance history. To identify patterns of pollinator richness and abundance in Idaho ROWs, we surveyed butterflies and sampled bees at a randomized set of 63 100-meter (328-foot) roadside transects in southeastern Idaho, stratified by highway class and NDVI (greenness) category. Lower NDVI (less green) sites, those with more flowering plant species, and sites along smaller, less-trafficked highways supported significantly more species of bees, while ROWs with more abundant flowers were associated with more species of butterflies. Low NDVI sites were often characterized by native sagebrush plant communities, while sites of high NDVI were associated with high proportions of non-native plants, suggesting that NDVI might be useful both in predicting bee richness and abundance (low values) and locating developing noxious weed patches (high values). These results, together with our management recommendations, can help prioritize ROWs for pollinator protection and increase their capacity to support diverse pollinator communities.Item Greater sage-grouse (Centrocercus urophasianus) nest survival and nest predator response to fence modifications in a grazing modified landscape(Montana State University - Bozeman, College of Agriculture, 2023) O'Harra, Aaron William; Chairperson, Graduate Committee: Bok Sowell; This is a manuscript style paper that includes co-authored chapters.Livestock operations are present across much of the greater sage-grouse (Centrocercus urophasianus; sage-grouse) current range and the infrastructure associated with this land-use type can have negative effects on sage-grouse populations. Recent work has found that the daily survival rate of nests placed close to fences experience a 4-fold decrease in survival probability. The reduction in survival was theorized to be attributed to higher use of fences by predators due to increased movement efficiency and foraging rates predators experience along linear features. In this study, we experimentally modified fences to reduce perch availability and the barrier effects often associated with fences to improve sage-grouse nest survival. We monitored 177 nests over 8 years to assess the effectiveness of this management technique. We also used camera traps and point count surveys in the last 3 years of the study to assess the occurrence of three common sage-grouse nest predators; badgers (Taxidea taxus), coyotes (Canis latrans), and avian predators. We modeled daily nest survival against modified and traditional fences and landscape features throughout our study area in a Bayesian framework. Our predator occurrence rates were modeled using a single season occupancy model in relation to similar landscape features used for nest survival modeling. We detected evidence of an increase in nest survival of 11.4% (90% CRI: 3.2%, 20.0%) for sage grouse nests placed closer to modified fences (mean survival = 35.8%) when compared to traditional fence types (mean survival = 24.4%). We also found evidence for a 14% (95% CI: 5%, 23%) decrease in badger occurrence and a 15% (95% CI: 12%, 18%) increase in coyote occurrence along recently modified fences. We found no evidence that avian predators used fences more than areas with no fence present. Our results may be influenced by the distribution of fence types between sagebrush species. Our results indicate that predation risk for sage-grouse nests across a landscape is predator specific. We conclude that modifying fences in this way can improve sage-grouse nest survival, and the effectiveness of these modifications is controlled by a combination of the predators and landscape features associated with a nest site.Item Building an inclusive land management and conservation decision-making system with local stakeholders of Ulaan Taiga Special Protected Area in Mongolia(Montana State University - Bozeman, The Graduate School, 2022) Dovchin, Badamgarav; Chairperson, Graduate Committee: Christine Rogers Stanton; Christine Stanton, Suzanne Held, Kristin Ruppel, Paul Lachapelle, Tumursukh Jal, herders user groups and the Community Advisory Board were co-authors of the article, 'Twin ride: integrating WSEK and TEK in Mongolia (literature review)' submitted to the journal 'The other ways of knowing' which is contained within this dissertation.; Christine Stanton, Suzanne Held, Kristin Ruppel, Paul Lachapelle, Tumursukh Jal, herders user groups and the Community Advisory Board were co-authors of the article, 'Community-based participatory research in action: lessons from communities in the Ulaan Taiga Special Protected Area bufferzone communities' submitted to the journal 'Journal of land management and appraisal' which is contained within this dissertation.; Christine Stanton, Suzanne Held, Kristin Ruppel, Paul Lachapelle, Tumursukh Jal, herders user groups and the Community Advisory Board were co-authors of the article, 'Building an inclusive decision-making system for buffer zone land management and conservation of Ulaan Taiga Special Protected Area' submitted to the journal 'The other ways of knowing' which is contained within this dissertation.Environmental degradation and its management are pressing issues worldwide, especially in developing countries. Mongolia is a nomadic culture country with publicly owned land grazed by privately owned herds of domestic animals experiencing intense land degradation (Ministry of Environment and Tourism of Mongolia, 2018). The Eurocentric system (Koobak et al., 2021) Western Science-Based Ecological Knowledge (WSEK) (Studley, 1998) was introduced first by communism, then global North aid programs. Mongolian government fully adopted WSEK methods despite the reality that people of Mongolia still utilize Traditional Ecological Knowledge (TEK) (Berkes, 2012; Jamsranjav et al., 2019). Gradually the disconnect between the stakeholders increased over the last 100 years. Climate change, socioeconomic pressures on publicly owned land, and multiple stakeholders who practice different decision-making systems call for collaborative facilitation and interventions. The purpose of this study is to examine the following two major points: 1. The possibility of addressing the land degradation issues by integrating TEK and WSEK through Community Based Participatory Research (CBPR) facilitations in the Darhad Valley, Mongolia (2014-2020). 2. The perceptions of buffer zone communities of Ulaan Taiga Special Protected Area (UTSPA) regarding their ability to manage their land and the ecosystem services it provides. Guidance and participation of locals and advisory board across all steps in the research process (Hallett et al., 2017; Stanton, 2014), and application of a CBPR framework help rebalance the power dynamics among the stakeholders (Coombe et al., 2020a) and bring shared ownership (D'Alonzo, 2010) and trust (P. R. Lachapelle & McCool, 2012) to decision-making. Our team concluded that integrated epistemologies offer added strength and innovation in addressing some of the complex challenges. We found that the 'twin ride' (integration) of WSEK and TEK complement each other (Maweu, 2011). CBPR provides a framework to facilitate collaboration, apply theory to practice in culturally and epistemologically appropriate ways specific to the host community (Stanton et al., 2020), and help overcome various barriers such as loss of trust, institutional differences, and give time to collectively develop shared goals (P. R. Lachapelle et al., 2003). CBPR is a complicated but rewarding, potentially healing process (Stanton, 2014a; Waddell et al., 2020).Item A multi-scale assessment of the coupling between the nitrogen cycle and the terrestrial carbon sink under global change(Montana State University - Bozeman, College of Agriculture, 2022) Gay, Justin David; Chairperson, Graduate Committee: Jack Brookshire; This is a manuscript style paper that includes co-authored chapters.It is now unequivocal that the main driver of greenhouse gas (GHG) accumulation in Earth's atmosphere over the industrial era has been due to anthropogenic global change. Despite the recent and rapid rise in GHGs, global terrestrial ecosystems have slowed the rate of carbon dioxide accumulation in the atmosphere, and thus the rate of climate change, through the uptake and storage of carbon (C) in plant biomass and soil organic matter. However, the global cycles of C and nitrogen (N) are tightly coupled through primary production and the turnover of soil organic matter, highlighting a stoichiometric relationship that is critical to understanding the future stability and strength of the terrestrial C sink. Thus, our ability to understand the response of the terrestrial C sink to global change hinges on critical -- but often overlooked -- feedback with N cycling. In this dissertation, I examine how different aspects of global change and land management practices are impacting the terrestrial C sink by evaluating interactions with the N cycle in both managed and natural ecosystems. I use observational and experimental methods to quantitatively assess C and N dynamics at plot, landscape, and global scales. I focus this work on crop- and range-lands of the Upper Missouri River Basin in the United States, and in equatorial mountain forests across the globe to address three overarching research questions: 1. What are the controls over the soil-atmosphere gas exchange of greenhouse gases, and how do they change in response to management and vegetation cover? 2. How do changes in plant community composition influence ecosystem C and N dynamics? 3. How is global change altering the stability and rate of C and N accumulation and storage?Item Pulse crop management to enhance biological nitrogen fixation in the northern Great Plains(Montana State University - Bozeman, College of Agriculture, 2022) Baber, Kaleb Wade; Chairperson, Graduate Committee: Clain Jones; Clain Jones, Perry Miller, Sydney Atencio, Samuel Koeshall and Peggy Lamb were co-authors of the article, 'Lentil nitrogen fixation response to fertilizer and inoculant in the northern Great Plains' submitted to the journal 'Agronomy journal' which is contained within this thesis.; Clain Jones, Kevin McPhee, Perry Miller and Peggy Lamb were co-authors of the article, 'Assessment of nitrogen fixation among pea and lentil varieties in the semiarid northern Great Plains' submitted to the journal 'Agronomy journal' which is contained within this thesis.Pulse crop production has increased dramatically in Montana and the surrounding northern Great Plains over the past few decades. Through N fixation, pulse crops, including pea and lentil, can reduce N fertilizer requirements, both by replacing non N-fixing crops and positively contributing to soil N pools for subsequent crop uptake. Three studies were conducted in Montana over three years to investigate pulse crop management practices that enhance N fixation of pea and lentil. The first study investigated lentil N fixation response to fertilizers and inoculant types. Inoculant and S fertilizer each increased N fixed by lentil in 40% of site-years, but response was not well correlated with cropping history or soil sulfate-S levels. In one site-year, N fixation appeared to continue increasing at the highest tissue S concentration while seed yield plateaued below that highest level, indicating that S fertilizer could increase the soil N benefit of lentil even if a yield response is not expected. Potassium fertilizer nor inoculant type influenced N fixed. The second study assessed differences in N fixation among lentil and pea varieties. Amounts of N fixed varied in 75% and 50% of site-years for lentil and pea, respectively. Differences among varieties were sometimes large, up to 45 kg N ha-1. Two lentil varieties, CDC Richlea and Riveland, were frequently among the top N-fixers, while no pea varieties consistently fixed more N than others. Correlations between N fixed and seed yield ranged from weak to moderate, and pea more frequently had positive relationships than lentil. The third study evaluated N fixation response of two pea varieties to inoculant formulations. Inoculant formulation did not impact N fixed by either variety, and the uninoculated treatment performed as well as the inoculated treatments. This suggests producers may not need to inoculate pulse crops to achieve sufficient N fixation when effective rhizobia populations exist in their fields. These results contribute to the researchers' understanding of N fixation by pulse crops in the region. Together, these studies can help producers in the northern Great Plains better manage pea and lentil, improving both economic and environmental sustainability of the region's cropping systems.Item Understanding mechanisms of invasion and restoring lands impacted by non-native annual grasses(Montana State University - Bozeman, College of Agriculture, 2020) Majeski, Michelle Lynn; Chairperson, Graduate Committee: Jane M. Mangold; Catherine Zabinski, Lisa J. Rew and Jane Mangold were co-authors of the article, 'Ventenata dubia growth responds to field soil inocolum but not phosphorous and potassium treatments' which is contained within this thesis.; Catherine Zabinski, Lisa J. Rew and Jane Mangold were co-authors of the article, 'Ventenata dubia was associated with perennial grasses, bare ground and soil potassium concentration' which is contained within this thesis.; Stacy C. Simanonok, Zach Miller, Lisa J. Rew and Jane Mangold were co-authors of the article, 'Spring seeding provides a seasonal priority effect for Pseudoroegneria spicata in Bromus tectorum-invaded rangelands' which is contained within this thesis.European settlement and development of rangelands in the western U.S. has led to a shift in vegetation from native species to introduced species, some of which have become weedy and invasive. Effects of invasive plant species can vary but often include replacing native vegetation, altering ecosystems, affecting wildlife that relied on the native plants for food and shelter, and toxicity to livestock. Two introduced annual grasses of concern are Ventenata dubia and Bromus tectorum. These grasses are at different stages in their invasion in the western U.S. Ventenata dubia is a recent invasive species in the past ten years and B. tectorum has been dominant in the Intermountain West since the mid-1900s. Three independent studies were conducted to understand characteristics of V. dubia invasion and to test whether a seasonal priority effect could be shifted to Pseudoroegneria spicata to outcompete B. tectorum in range/pasturelands. A full-factorial design was executed in a greenhouse setting to examine if a plant-soil feedback contributes to V. dubia invasion and if V. dubia preferred specific nutrients for growth. Ventenata dubia biomass, shoot height and number of leaves and tillers (per plant) were higher when grown with field soil inoculum compared to sterilized greenhouse soil. Ventenata dubia growth varied among nutrient treatments, but trended higher with a full nutrient solution. A nested observational study was conducted to examine abiotic and biotic characteristics associated with V. dubia infestations. Ventenata dubia was positively associated with non-native perennial grasses and negatively associated with native perennial grasses, bare ground/rock and soil potassium concentration. A randomized split-plot design was performed in B. tectorum-infested range and pasturelands to test whether timing of herbicide application and seeding of P. spicata could create a seasonal priority effect for P. spicata. Bromus tectorum had lower cover and biomass (per m2) with spring herbicide application. Higher P. spicata density, cover and biomass resulted with spring seeding after B. tectorum was reduced. These studies show that established and seeded native perennial grasses can compete with nonnative, invasive annual grasses. When existing management tools (herbicide and revegetation) are applied in a different way, native perennial grasses benefit.Item Effects of grazing management on sharp-tailed grouse ecology in mixed-grass prairies(Montana State University - Bozeman, College of Agriculture, 2019) Milligan, Megan Cochran; Chairperson, Graduate Committee: Lance McNew; Lorelle I. Berkeley and Lance B. McNew were co-authors of the article, 'Effects of rangeland management on the nesting ecology of sharp-tailed grouse' in the journal 'Rangeland ecology and management' which is contained within this thesis.; Lorelle I. Berkeley and Lance B. McNew were co-authors of the article, 'Effects of rangeland management on the survival of adult sharp-tailed grouse' submitted to the journal 'Journal of wildlife management' which is contained within this thesis.; Lorelle I. Berkeley and Lance B. McNew were co-authors of the article, 'Effects of rangeland management on the habitat selection of sharp-tailed grouse in the mixed-grass prairie' submitted to the journal 'PLOS one' which is contained within this thesis.Many grassland species co-evolved with large herbivores and require habitats along the entire structural gradient created by grazing. Widespread declines of grassland birds, however, have prompted concerns about rangeland management. Conceptually, rest-rotation grazing functions as a conservation strategy to mimic historic disturbance regimes and create pasture-level heterogeneity in the absence of fire, but its utility for improving grouse habitat has not been tested. We evaluated rest-rotation grazing as a conservation management technique compared to traditional grazing systems, including summer rotation and season-long grazing, and assessed the effects on sharp-tailed grouse (Tympanuchus phasianellus), an indicator species for grassland ecosystems. We monitored radio-marked female sharp-tailed grouse in eastern Montana and western North Dakota during 2016-2018 to monitor nesting ecology, adult survival, and habitat selection. Both nest site selection and nest survival were directly related to vertical nesting cover, which was only weakly related to grazing management variables, including grazing system and stocking rate, at moderate stocking rates (< or = 2 AUM ha^-1). Cattle presence during the nesting period had a positive effect on daily nest survival, potentially because either the cow or rancher presence affected predator behavior. Grazing management did not have a meaningful influence on any aspect of the overall survival of adult female sharp-tailed grouse, although seasonal patterns of mortality risk differed among systems. More importantly, cropland increased mortality risk of adult female sharp-tailed grouse. At broad spatial scales, females selected for grassland habitats, but exhibited limited to no selection for either landscape or management variables when selecting habitat at smaller spatial scales. We found limited evidence that grazing management was a driver of habitat selection at either spatial scale examined. Furthermore, female sharp-tailed grouse exhibited strong individual variation in both home range size and third-order habitat selection. Taken together, our results suggest that rest-rotation grazing did not influence any aspect of sharp-tailed grouse ecology we studied relative to other grazing systems and did not increase pasture-level heterogeneity in relevant vegetation variables. Therefore, grazing management strategies with moderate stocking rates that preserve large intact grasslands are a better conservation strategy for sharp-tailed grouse than prescribing specific grazing systems.Item Optimizing efficacy of Bromus tectorum (cheatgrass, downy brome) biological contorl in crops and rangelands(Montana State University - Bozeman, College of Agriculture, 2017) Ehlert, Krista Ann; Chairperson, Graduate Committee: Fabian D. Menalled; Jane M. Mangold (co-chair)Management of Bromus tectorum L., an annual grass invasive in western North America, has focused on single and integrated methods across crop and non-crop settings. Extensive literature does not exist on the integration of Pyrenophora semeniperda, a generalist grass pathogen for B. tectorum control, which has been used experimentally with some success to control B. tectorum. However, questions remain about (1) the risk of non-target effects on grassy species, (2) efficacy as part of an integrated management plan, and (3) efficacy under different environmental conditions and on different B. tectorum populations. I sought to answer these questions with three distinct studies. First, I assessed the risk of P. semeniperda on B. tectorum and 15 co-occurring grass species in a greenhouse setting. Pyrenophora semeniperda reduced B. tectorum density by 40% but also negatively affected density of 60% of the non-target species tested, particularly native rangeland grasses. Second, I integrated P. semeniperda as part of a two-year rangeland revegetation management plan that included an herbicide (imazapic), a fungicide seed treatment, and different perennial grass seeding rates. Application of P. semeniperda did not increase inoculum loads above ambient levels, and there was no effect of seeding rate or seed treatment on B. tectorum or seeded perennial grass density or biomass. However, B. tectorum density was reduced by 60% the first year with a single imazapic application. Lastly, I compared the effects of temperature (13°C, 17°C, 21°C, 25°C, 32°C) and B. tectorum populations (range, crop, sub-alpine) on infection and mortality rates caused by P. semeniperda using a temperature gradient table. Infection rates by P. semeniperda peaked at intermediate temperatures (17°C, 21°C, 25°C) for range and sub-alpine populations, but were generally low and not as influenced by temperature in the crop population. Overall, B. tectorum control with P. semeniperda is possible, provided (1) non-target effects are considered, especially for range species, (2) research is conducted to increase P. semeniperda inoculum loads above ambient levels and revegetation is used with other control tactics, and (3) we take into account how distinct B. tectorum populations respond to P. semeniperda.Item The condition of the northern winter range in Yellowstone National Park : a discussion of the controversy(Montana State University - Bozeman, 1981) Tyers, Daniel Bruce; Chairperson, Graduate Committee: J. E. (John Edgar) Taylor