Theses and Dissertations at Montana State University (MSU)

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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.
The effect of the covid-19 pandemic on backyard bird feeding habits and populations using a citizen science approach
(Montana State University, 2021) Rittner, Zachary Francis
Citizen science is an effort to engage the public in scientific practice and enhance the educational experience for science students. The COVID-19 pandemic has forced most residents to isolate themselves in an effort to control the spread of the disease. As a consequence, backyard birdwatching and feeding have become increasingly popular, but the ecological effects of increased supplemental feeding for backyard birds are largely unknown. Monitoring changes in the abundance of common backyard bird feeder species in the towns of Scotch Plains-Fanwood Ecosystem (SPFE), New Jersey through the Great Backyard Bird Count (GBBC) could provide insights into motivating students through authentic, community-based learning and how changes in human behavior during the pandemic have contributed to population dynamics of the bird community of the SPFE through changes in resource availability. Students at Scotch Plains-Fanwood High School participated in a minimum of 15 consecutive minutes of bird watching during the GBBC in 2020 and 2021 at locations within the SPFE. In addition, students were asked to complete a survey evaluating the effectiveness of the Great Backyard Bird Count in engaging the public through citizen science. The results indicated that fewer total individual backyard birds were reported during the COVID-19 lockdown compared to the count before the lockdown in 2020 within the SPFE. In contrast, the increases in adjusted Simpson and Shannon indices suggest an increase in species diversity by 9-21% from 2020 to 2021. The increase in diversity may be partly explained by the 25% increase in the number of feeding stations. However, the data potentially have considerable uncertainties associated with small sample size, inconsistencies in observation duration, available resources (training, equipment, available instructors, etc.), all of which are challenges typical of citizen science and working with teenagers during a global pandemic. Finally, participant feedback regarding the effectiveness of citizen science was overwhelmingly high and demonstrated clear public engagement in and admiration of the scientific process.
Using remote sensing indices to analyze the influence of bare ground in dust source areas to total dust-on-snow load in the san juan mountains, colorado
(Montana State University, 2021) Bilbrey, Christopher Edward; Chairperson, Graduate Committee: Scott Powell
The movement of dust across the western United States (US) has increased exponentially over the last 20 to 30 years driving a positive feedback regime altering the timing and magnitude of snowmelt. Dust radiative forcing of snowmelt can potentially exceed present day and likely future greenhouse gas forcing by two orders of magnitude. The semiarid landscape of the Colorado Plateau is one of the largest sources of dust in the western US. MODIS satellite imagery has been used to identify frequent, large-scale dust plumes that originate in the dust source area of northeastern Arizona, US and deposit that dust in the San Juan Mountains, Colorado. My study attempted to distinguish a "tele-link" between vegetation vigor in the dust source area and end of season total dust load in the San Juan Mountains from October 1 to June 30 for the years 2016 to 2021. The Normalized Difference Vegetation Index (NDVI) is a principal index tool used in multitemporal vegetation monitoring, and is commonly used as a direct indicator of vegetation health and growth. NDVI allows us to delineate the distribution of vegetation and bare soil based on the characteristic reflectance patterns of green vegetation. My study compared monthly NDVI mean values acquired by MODIS and Sentinel-2 to evaluate each satellites efficacy at modeling vegetation cover. Results suggest the association between vegetation vigor, bare soil, and total dust load is more complex and a number of factors could influence the inter-annual variability of dust-deposition. Statistical analysis employing ANOVA and multiple means comparison effectively identified pairwise groups who's monthly NDVI mean values were significantly different from others and 95% confidence intervals of the true expected difference, but failed to distinguish a "tele-link" between change in vegetation vigor and end of season total dust load. Finer-spatial resolution imagery captured more local variability in change in vegetation vigor over time and expanded the significant NDVI sampling window from 30 to 60 days. Projected climate change will likely increase aridity in the southwestern US, reduce the amount of vegetation cover, increase the amount of bare soil and enhance dust emission throughout the years.
Factors influencing the effectiveness of canada goose relocation in georgia, usa
(Montana State University, 2021) Beard, Sarah Elizabeth; Chairperson, Graduate Committee: Tracy M. Sterling
An iconic species of North American waterfowl, Canada geese (Branta canadensis) have established an overabundant resident population in Georgia, USA. As a consequence, wildlife managers respond to a growing number of complaints from landowners in urban areas where Canada geese pose a threat to property and human safety. Some landowners rely on relocation when other methods are unsuccessful at sites with nuisance Canada geese; however, some studies show that relocation may be ineffective when geese return to their original capture site. To analyze factors that may influence returning geese that were relocated in Georgia, I gathered data from USDA-APHIS on nuisance Canada geese that were captured, banded, and relocated to rural, hunted areas within Georgia from 2010 to 2019. I compared the nonrecaptured population with the recaptured population for differences in age, sex, and relocated distance. I found a relationship between age and recapture status (X2 (1, N = 4,058) = 14.17, p = .0002) as well as relocated distance and recapture status (X2 (2, N = 4,059) = 9.54, p = .0085), but no evidence of an association between sex and recapture status. There were fewer juvenile Canada geese than expected among the recaptured sample. In addition, among the recaptured sample, there were fewer than expected geese that were relocated greater than 250 kilometers away. I found an overall 2.5% recapture rate by USDA-APHIS personnel at nuisance sites. I recommend continuing relocation efforts at distances greater than 150 kilometers and at least 250 kilometers when possible. Due to nuisance complaints at recurring sites throughout the 10-year period, I recommend increasing initiatives to educate urban landowners in preventive and pre-planned measures (e.g., egg addling, predator decoys) to manage nuisance populations.
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 Powell
The 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.
Elk harvest and the accessibility of hunt districts: does road density influence hunter harvest success?
(Montana State University, 2021) Little, Katelynn Rae; Chairperson, Graduate Committee: Tracy M. Sterling
Wildlife managers are constantly faced with the difficulty of balancing growing demands for elk hunting opportunities and maintaining elk populations. Presence of roads and associated impacts to elk movements, behaviors, and vulnerability/mortality has been widely studied, with a general consensus of negative impacts to elk where roads are open to motorized use. Road density has also been shown to influence hunter densities and hunter effort which may indirectly effect harvest success. Previous studies analyzing elk harvest were limited to bull harvest only, certain hunting seasons, or lacked spatial replicates. The purpose of my study was to analyze road density and associated, all-inclusive harvest metrics on public land in 13 hunting districts of southwest Montana. Harvest was analyzed in two ways: estimated harvest number and harvest success (percentage successful hunters to total hunters). I obtained harvest reports for 2014 to 2016 data on hunter harvests. I used road data from the Forest Service, Bureau of Land Management, and Montana Department of Transportation, as well as public land GIS data from the state of Montana. GIS methods were conducted using QGIS. I conducted linear regression analyses to determine whether independent variables (road density, hunter density, hunter to elk ratios, hunter effort) were significant predictors on response variables (harvest number or success). Road density and hunter density were not significant predictors of harvest (number or percentage), while hunter effort and hunter to elk ratios were only significant predictors of harvest number. Road density on its own may not significantly predictor of harvest, but traffic on roads might. Hunter density was not directly linked to road density; therefore, it is unclear whether road density influenced hunter density and consequently harvest. One limitation was the lack of data for trails open to motorized use. Motorized route density may have been greater if open trails were included. Hunter effort and hunter to elk ratios may be useful to wildlife managers for predicting elk harvest numbers. If harvest numbers increase when these metrics increase, managers could implement changes to hunting in certain areas to increase hunter interest, therefore increasing hunters and potentially increasing harvest number.
Conservation guidance for blanding's turtles in northwest iowa
(Montana State University, 2021) Howing, Drew Taylor Lee
Blanding's turtles (Emydoidea blandingii) are currently threatened or endangered across their range in the United States and Canada due to habitat destruction and fragmentation. In Iowa, a recent survey from 2010 states that they currently reside in only 26 of the original 45 counties they historically inhabited. Due to the habitat differences across their range, developing survey protocols for the prairie pot-hole region of northwest Iowa is needed. Within Dickinson, Clay, and Palo Alto counties of Iowa, Blanding's turtles have been detected historically and contain a greater abundance of wetland habitats than the surrounding counties. The goal of this project was to assess different survey and capture techniques to inform future monitoring programs for Blanding's turtles in this region of Iowa. I used visual rapid assessments and hoop net trapping to detect, capture, and mark Blanding's turtles throughout the 2020 and 2021 field seasons. These surveys and trapping efforts were mostly conducted throughout the month of June, which is later than most literature would recommend due to reduced turtle basking behavior. However, due to the proliferation of submergent vegetation as the summer progressed, it seems likely that the detection of this species could be greater using these methods later into the summer as turtles venture out into more open areas of wetlands. In addition, these methods led to the discovery of multiple viable Blanding's turtle populations and new sites where the species is present. An additional spatial analysis concluded the presence of perennial streams in turtle home ranges which could be an important habitat factor for their existence in the boom-and-bust cycles of the prairie. Further research needs to be conducted using these methods for developing a more robust dataset to determine the effectiveness of this method. Long-term monitoring will be initiated using a field maps survey created by Iowa Lakes Community College students for increasing efficiency of data collection by managers and other professionals that encounter this species. In addition, funding for the purchase of 25 radio transmitters has been received for marking and tracking adult male and female turtles. These data will give a population-level understanding of future conservation action needed for their habitat management.
Resilience of sagebrush steppe plants nine years after fire and soil disturbance in southwest montana
(Montana State University, 2021) Newell, Isaac Todhunter
Sagebrush steppe in the western United States faces an increasing risk of degradation and overall habitat loss from land use and climate change. One important result of these drivers is the spread of the nonnative annual grass, Bromus tectorum. In many of these grasslands, B. tectorum has altered fire regimes through a positive feedback loop in which increased B. tectorum leads to more severe and frequent fires, and consequently increased B. tectorum cover. This ultimately displaces native flora and fauna, moving grasslands away from historic structure and function. However, in the northern portion of the sagebrush steppe, native communities were recently found to be resilient to fire 3 years post-fire, but not to soil damage. I revisited the study site (Red Bluff, Montana, US) to evaluate how this plant community has responded to fire and soil damage 9 years after disturbance. I sampled the same three treatments: an area burned by the 2012 Red Bluff fire, an adjacent unburned area, and a bulldozed firebreak between the two. In each treatment, 28 x 1m2-plots were sampled along three transects running parallel to the fire break. Percentage cover of each species, litter, bare ground, rock, and manure were recorded and analyzed for differences in richness, ground cover, and Bromus tectorum cover, as well as alpha- and beta-diversities, using generalized linear models. Nearly a decade after disturbance, fire and soil damage still significantly affected species richness (p = 0.05) and species composition (p = 0.02). Both the unburned and burned treatments had a greater cover of native species than did the bulldozed plots (p < 0.01). Bromus tectorum was the most abundant species in the bulldozed treatment, with 186.7% greater relative abundance than unburned treatment, and 107.6% greater than the burned treatment (p < 0.01). This shows that while the plant community is resilient and resistant to nonnative invasion after fire, it is much less so after soil disturbance. This may have implications on future applications of fire breaks and the way they are managed after fire, as well as other mechanical disturbances to soil structure.
Analysis of cleanups of lead-contaminated residential soils at u.s. smelter superfund sites
(Montana State University, 2021) Tan, Robert
Lead contamination from historic smelting operations continues to pose a public health risk in the United States, particularly from exposure to contaminated soils. Epidemiological studies have shown that concentrations of lead in residential soils can result in unacceptable exposures, and that there is no apparent blood lead concentration that may entirely avoid adverse health effects. These findings have caused regulatory agencies to gradually reevaluate previous blood lead targets and cleanup levels for lead sites. The U.S. Environmental Protection Agency (EPA), which is responsible for conducting cleanups of large-scale lead smelting sites that are on the National Priorities List, has acknowledged current literature that demonstrates risks from trace exposures, but has not yet revised the 1994 blood lead level target of 10 ?g/dL. This ambiguity is coupled with regional delegations of authority that have resulted in varied approaches to addressing lead contamination within the Superfund program. These inconsistencies create a challenge to remedial project teams tasked with determining strategies to address these future sites. I address this challenge by conducting a first-of-its-kind comprehensive evaluation of residential cleanups at lead smelter Superfund sites. By using publicly available data from decision documents for 31 lead smelter sites across the US, I identify predominant cleanup strategies. Although the evaluations demonstrate inconsistent blood lead targets and cleanup levels used between sites, they also illustrate commonalities in the type of remedy selected as well as general costs for residential cleanups conducted by EPA's removal and remedial programs. My results indicate that remedial project teams should embrace strategies that use both removal and remedial actions to address residential soil contamination and should expect to select a remedy based on excavation and backfill of contaminated properties. Soil amendments may be able to reduce lead bioavailability but have only been used for residential properties at one site and were unable to achieve residential cleanup standards. Last, my paper provides average preliminary cost estimates for residential cleanups, ranging from $434 per yd3 removal actions, and $125 per yd3 for remedial actions. Although costs differ substantially between sites, these general estimates provide a starting point for early planning efforts.
Improving restoration of breeding sites to increase recruitment of anaxyrus boreas in western montana
(Montana State University, 2021) Johns, Nathanael David; Chairperson, Graduate Committee: Scott Powell
The Montana native western toads (Anaxyrus boreas) have, like most amphibians, been declining in recent years. Although it is endangered and at high risk of extirpation in many states, there are still several healthy breeding populations in Montana. Montana can increase recruitment of this increasingly rare anuran species through habitat restoration. However, using habitat restoration to addressing the decline of this species is not well researched. Here, I evaluate potential restoration methods that could increase recruitment. I provide an overview of the habitat requirements and preferences of A. boreas as well as effective restoration methods for this and other anuran species. To increase recruitment, restoration efforts should include construction of permanent ponds with low turbidity and extensive shallows that gradually increase to a maximum depth of 40 cm. Trees should be removed along the pond perimeter if they shade the water. Active management measures such as sediment removal in ponds, strict regulation of livestock grazing, periodically prescribed burns, and removal of invasive species such as the American bullfrog (Lithobates catesbeianus) should also be implemented. Farther from the breeding site, native deciduous shrubs should be planted, if they are not otherwise present. For existing breeding sites, the area within a 3-km radius should be protected from development and clearcuts. Introduction of beaver (Castor canadensis) to their historical range will also have a significant beneficial impact on the restoration of A. boreas. The locations of these efforts should also be carefully chosen to take into account the continuing effects of climate change. Taking these actions now, based on the data that are available, will help increase recruitment and improve the chances of this species recovering.

Theses and Dissertations at Montana State University (MSU)

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