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    Taxonomic studies on West Indian Staphylinidae
    (Montana State University - Bozeman, College of Agriculture, 2024) Rainey, Jordan James; Chairperson, Graduate Committee: Michael A. Ivie; This is a manuscript style paper that includes co-authored chapters.
    Aleomallus yaque Rainey and Ivie, new genus and species is described from high- elevation areas in the Dominican Republic and placed in the Aleocharinae tribe Diestotini. This placement is discussed with a review of the history of the tribe and related groups. A description with figures of diagnostic characters is provided. This discovery highlights the extent of undescribed Aleocharinae biodiversity in the mountains of the West Indies. The West Indian species of Belonuchus Nordmann, 1837 are revised to address a knowledge gap in our understanding of the genus. The genus now contains 17 species found in the West Indian biogeographical area, seven of which are described as new species: Belonuchus blackwelderi, new species (Hispaniola), Belonuchus crypticus, new species (Hispaniola), Belonuchus draco, new species (Hispaniola), Belonuchus franki, new species (Jamaica), Belonuchus sanchezi, new species (Hispaniola), Belonuchus dominici, new species (Hispaniola), and Belonuchus tenebros, new species (Hispaniola). The following new synonymies are proposed: Belonuchus hispaniolus Blackwelder, 1943 = Belonuchus gagates Erichson, 1840, new synonymy, Belonuchus oakleyi Blackwelder, 1943 = Belonuchus gagates Erichson, 1840, new synonymy. A lectotype and paralectotypes are designated for Belonuchus coeruleus Cameron, 1922, and Belonuchus cognatus Sharp, 1885. A lectotype is designated for Belonuchus eximius Bernhauer, 1917. Redescriptions and rediagnoses are provided for previously described species. All species are included in a taxonomic identification key, diagnostic characters are illustrated, distribution maps are presented for each species, and updates on the nomenclature of the group are provided.
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    A comprehensive study on forest management and wildfire trends in dry western coniferous regions of the United States
    (Montana State University - Bozeman, College of Agriculture, 2024) Schonenberg, Richard Herman; Co-chairs, Graduate Committee: Anthony Hartshorn and William Kleindl
    In response to the growing concern over the escalating severity of wildfires in dry coniferous forests across the Western United States, this study aims to evaluate the effectiveness of Managed Fire Operations (MFO) in mitigating wildfire severity. By leveraging satellite-derived fire severity data, specifically the Difference Normalized Burn Ratio (dNBR), I conducted a comprehensive analysis comparing fire severity between forest lands with and without MFO, subsequently affected by wildfires. Employing a paired study design, I analyzed wildfire events from 1985 to 2021 within dry coniferous forests, limited to south-facing slopes with moderate terrain gradients, using fire perimeter data from the Monitoring Trends in Burn Severity (MTBS) program. Geospatial analysis identified areas where wildfire perimeters intersected with MFO-designated zones, enabling the delineation of new burn perimeters for each wildfire. The results revealed that regions subjected to MFO before wildfires experienced a statistically significant decrease in fire severity compared to areas without MFO (Wilcoxon signed-rank test, p-value < .01). Ecoregion stratification revealed notable variations, with the Northwestern Forested Mountains showing an estimated median fire severity difference nearly three times greater than the Temperate Sierras. Further stratification by time since MFO implementation displayed consistent, modest reductions in fire severity across two intervals (0-15 years and 15-40 years), with minimal variations between the temporal categories. These results highlight the effectiveness of MFO in mitigating wildfire severity and emphasize the importance of regional context and temporal factors in evaluating MFO efficacy in Western U.S. dry coniferous forests over the past four decades.
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    Understanding the effects of floodplain shade on hyporheic and stream channel temperature cycles
    (Montana State University - Bozeman, College of Agriculture, 2024) Fogg, Sarah Kathleen; Chairperson, Graduate Committee: Geoffrey C. Poole; This is a manuscript style paper that includes co-authored chapters.
    River reaches with coarse-grained alluvial floodplains have a breadth of lateral interaction between the channel and surrounding landscape, yielding extensive riparian zones and high rates of gross water exchange between the channel and substrate (i.e., hyporheic exchange). The lateral hyporheic zone on floodplain rivers is often near the ground surface, allowing for heat exchange between the atmosphere, unsaturated sediments, and hyporheic zone. We hypothesized that floodplain shade overlying lateral hyporheic water influences the conductive heat flux through unsaturated sediments, thus influencing hyporheic temperatures and temperatures in associated stream channels. We conducted simulation modeling experiments to test the potential effects of floodplain shade on hyporheic and stream channel temperatures. We found that scenarios with floodplain shade led to cooler hyporheic and stream temperatures than scenarios lacking floodplain shade under a variety of realistic floodplain conditions. We conclude that floodplain forest shade is a novel consideration for riparian management on floodplain river reaches and may be crucial in managing and maintaining cold-water habitat into the future.
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    Soil health response to cropping systems in semi-arid Montana
    (Montana State University - Bozeman, College of Agriculture, 2024) Ashford, Zane Ann; Chairperson, Graduate Committee: Catherine A. Zabinski
    Traditional cropping systems in the northern Great Plains (NGP) were dominated by cereal-fallow rotations until the 1970s, resulting in increased soil erosion, decreased soil organic matter (SOM) accumulation, and declines in soil biological activity. Recent shifts toward continuous and more diverse no-till crop production attempt to increase sustainability, diversify economic opportunities, and keep up with the growing food demand without converting more land into agriculture. With a two-year study, I explored the effects of crop types in diverse, no-till, crop sequences on soil health in dryland and irrigated systems on one farm in semi-arid Montana, using biological indicators of potentially mineralizable nitrogen (PMN), soil enzyme activity (beta- glucosaminidase, beta-glucosidase, arylsulfatase, and acid and alkaline phosphatases), and permanganate oxidizable carbon (POxC), a measure of labile carbon. Crop sequences included four crop types -- cereals, oilseeds, legumes, and root crops. Root crops, namely sugar beet, drove soil responses in PMN, evident by increased plant-available N in soils following sugar beet. Soil enzyme activity, an indicator of nutrient cycling capacity, was strongly correlated with SOM, but did not follow a pattern based on crop type. Labile carbon changed in soils between years but did not respond consistently to crops. This research also explored the soil health gap by comparing soil health in cultivated systems to nearby grasslands. In a paired-site comparison on two farms in Montana, biological health indicators were 45% lower, on average, in cultivated soils compared to adjacent uncultivated soils. This difference was consistent with lower SOM averages, offering a simple assessment to quantify the maximum attainable soil health capacity within a specific agroecosystem. Soil acidification, a growing concern for producers across the NGP, contributed to 42% lower soil enzyme activity, based on four enzymes, compared to adjacent neutral pH cultivated soils. Enzyme activity was the only soil health parameter that was lower in acid soils compared to neutral pH soils, demonstrating the sensitivity of soil enzymes. Overall, these results indicate that biological soil health indicators are sensitive to changes in crop production, changing yearly, and provide farmers with the opportunity to fine- tune their management practices to meet their soil health goals.
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    Tracing interactions of hydrogeology and land use in two Montana watersheds
    (Montana State University - Bozeman, College of Agriculture, 2024) Keeshin, Skye Ilan; Chairperson, Graduate Committee: Stephanie A. Ewing
    Hydrogeologic systems dictate the introduction, transport, processing, and mixing of groundwaters, with implications for both groundwater and surface water quality. Land use can transform hydrogeologic processes and water quality through contributions of human amendments, alteration of soil and aquifer materials, and redistribution and consumption of water resources. Groundwater transit times are also orders of magnitude longer than those of surface water systems, resulting in lag times in water quality changes. In this thesis, I examine water quality consequences of land use in Montana at two headwater sites using geochemical tracers in groundwater and surface water. The first is within the Powder River Basin, the largest coal producing region in the US, where manmade aquifers composed of spoils from mine overburden replace existing unconsolidated and bedrock aquifers with salinity effects on downgradient waters. In a reclaimed coulee supplying groundwater to Rosebud Creek, a tributary of the Yellowstone River, geochemical and isotopic tracers reveal lateral contributions that contribute to dilution of high salinity mine-derived waters. These contributions include local inputs from shallow unconsolidated and bedrock aquifers and inputs of water on the order of 10,000 years from regional bedrock systems. The second site is the Gallatin Valley, a rapidly urbanizing intermountain basin in the Upper Missouri headwaters, where groundwater and surface water transects reveal mixing of water with a range of ages from a few years to 100,000 years. While not associated with spatial variation in nitrate concentration, these contributions likely attenuate rising nitrate concentrations in the valley aquifer as a whole over time, reflecting spatially variable loading from a legacy of agricultural fertilization and increasingly prevalent septic wastewater systems. A large component of the Gallatin Valley aquifer is decades old water sourced from higher elevation precipitation, consistent with long travelled mountain front stream losses. This component may diminish over time with an increasingly limited snowpack. Overall, hydrogeologic systems in these two land use regimes limit but do not eliminate effects of human-derived water quality concerns, and documenting them will improve water quality forecasting with impending changes in snowpack and precipitation.
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    Assessing and improving sustainability of Camelina sativa through rhizobacterial inoculants and soil enzymatic activity
    (Montana State University - Bozeman, College of Agriculture, 2023) Stowell, Henry Douglas; Co-chairs, Graduate Committee: Catherine A. Zabinski and Jed O. Eberly
    Camelina sativa is an oilseed crop with potential to be used in biofuel production as an alternative to contemporary fossil fuels. To ensure biofuels are a more sustainable alternative , considerations and improvements must be made regarding the inputs and land-use needs of producing biofuel feedstocks. This research assessed the beneficial effects of inoculating C. sativa plant growth-promoting rhizobacteria candidates in greenhouse trials. Additionally, we explored agronomic responses of C. sativa and bulk soil enzymes in field trials across Montana to nitrogen and sulfur fertilizer treatments applied as pelleted urea and gypsum respectively. Co- inoculations of Pseudomonas putida ATCC 12633 and Bacillus thuringiensis ATCC 33679 were associated with seed yield increases of 60% relative to the uninoculated control. Co-inoculations of Pseudomonas brassicacearum 36D4 and B. thuringiensis ATCC 33679 were associated with significantly shortened root lengths of early seedlings but did not reduce total biomass. Field trials found a strong seed yield response to nitrogen treatments, with yields increasing with each treatment up to 168 kg N/ha. No significant yield response to sulfur treatments was observed. Additionally, fertilizer treatments did not have any significant effects on the activities of arylsulfatase, beta-glucosaminidase, beta-glucosidase, or urease in soils sampled at crop flowering. Rhizobacterial inoculants have potential to improve crop yields without additional inputs and should be tested on C. sativa in field settings. Urea applications can be used to improve C. sativa yields without any short term effects on soil enzymatic activity, but longer-term studies are needed to accurately determine the effects of the crop and its inputs on soil properties.
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    In-nii (Bison bison L.) reintroduction to Amskapiipikini (Blackfeet) Nation homeland: relationships with ksahko (soils)
    (Montana State University - Bozeman, College of Agriculture, 2022) Tatsey, Latrice Dawn; Chairperson, Graduate Committee: Anthony Hartshorn
    In-nii (American Bison) are returning to their Traditional Territories after being nearly wiped out of the Great Plains of North America and Canada. The in-nii are slowly returning to Native American tribes who have the resources to run reintroduction programs like that of the Amskapiipikini (Blackfeet). This in-nii reintroduction presented an opportunity to look at the effects of the return of in-nii to the Amskapiipikini, and what their influences might be on the soils, plants, and water resources of the Blackfeet Nation. This research project was conducted on the Blackfeet Buffalo (In-nii) Ranch and the adjacent RRJ Cattle Ranch, comparing the influence of in-nii and cattle on soil nutrient cycles and soil carbon dynamics. Soil samples were taken from locations on the landscape that were near water sources on lower elevations, mid hillslopes for mid-elevation sites and on hilltops at higher elevations. Soil characteristics included soil organic matter (SOM), nitrate, pH, cation exchange capacity (CEC), and exchangeable calcium, potassium, sodium, and magnesium. Only two (CEC, magnesium) appeared to have been influenced by in-nii and cattle. The remaining soil characteristics were little influenced by grazer type. Substrate-induced respiration was also measured in the lab to see how microbes decomposed SOM (carbohydrates and other molecules) to release energy and CO2; we found no evidence of differences between in-nii- and cattle-influenced soils. Finally, we measured field respiration rates and water infiltration rates at multiple fence line sites; field soil respiration rates increased when soil had water infiltrated after the dry readings, soils also increased the time to absorb water after the first infiltration tests were run. Our preliminary results suggest that the reintroduction of in-nii to these lands has not yet resulted in measurable differences in soil-related properties of the Blackfeet Nation. Even so, the return of the in-nii for the Amskapiipikini is also about understanding the importance of using cultural science when studying the ecology of a system. Doing this can create an understanding of the traditional ways of knowing while bringing cultural healing and restoring connections between Amskapiipikini, in-nii, and land.
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    Integration of Puccinia punctiformis into organic management of Cirsium arvense
    (Montana State University - Bozeman, College of Agriculture, 2023) Chichinsky, Daniel Jacob; Chairperson, Graduate Committee: Fabian D. Menalled; Tim F. Seipel (co-chair)
    Cirsium arvense is a perennial weed that causes significant economic losses in agriculture. An extensive rhizomatous root system makes C. arvense difficult to manage, particularly in organic cropping systems that use tillage as a primary management tool. To improve organic management of C. arvense, there is a need for the development of alternative and integrated weed management toolsets that include C. arvense biological controls. Puccinia punctiformis is a fungal pathogen that systemically infects C. arvense, with the potential to reduce host vigor. The goal of this research was to assess the impacts of P. punctiformis within organic cropping systems, using a greenhouse and a field study that examined integration of the biocontrol with cultural and mechanical management tools. In the greenhouse, P. punctiformis was integrated with a competitive annual cropping sequence, where C. arvense's biomass production and competitive ability was assessed. Cirsium arvense biomass production was significantly reduced when P. punctiformis was integrated with the cultural management tactic, more than individual use of the biocontrol or cultural management alone. Additionally, P. punctiformis reduced the competitive ability of C. arvense over time. In the field, P. punctiformis was integrated with mechanical management, where reduced and standard tillage treatments were evaluated to determine the effects on P. punctiformis and C. arvense abundance. The reduced tillage treatment caused a greater increase in P. punctiformis infected C. arvense stems compared to standard tillage, however there was no impact to asymptomatic C. arvense stem density from either tillage treatment. In both tillage treatments, there was a reduction in asymptomatic C. arvense stem density in samples where P. punctiformis infection was present. Integration of P. punctiformis with cultural and mechanical tools can be an effective way to reduce C. arvense vigor. However, successful integration of the biocontrol can be dependent on a combination of environmental factors and deliberate cropping system management. While P. punctiformis is not a singular management solution, it has potential to be integrated into reduced disturbance cropping systems for long-term and sustainable C. arvense management.
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    Aquatic invertebrate colonization as a river restoration success criterion: a case study of the upper Blackfoot mining complex superfund site
    (Montana State University - Bozeman, College of Agriculture, 2023) Deyoe, Matthew Len; Co-chairs, Graduate Committee: Anthony Hartshorn and William Kleindl
    In 1975 the Mike Horse Dam partially collapsed, releasing 200,000 tons of cadmium, copper, iron, lead, manganese, and zinc into the streams and floodplains on the Upper Blackfoot Mining Complex (UBMC) in Montana, USA. The magnitude of the material that was toxic to humans from this event triggered the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), which currently governs 1,329 sites across the USA. Portions of the $39 million lawsuit in 2008 with the American Smelting and Refining Company (ASARCO), funded the remediation and restoration of 37 hectares of floodplains, wetlands, and stream channels. Although CERCLA's success criteria focus on reducing risk to human health from hazardous substances, the Montana Natural Resource Damage Program was interested in aquatic invertebrate colonization of the restored river ecosystems, since they are monitoring progress of restoration. To answer this, I explored whether observations of invertebrate colonization could gauge restoration success and identify aquatic invertebrate-based tools for future restoration projects. Over three years, I compared invertebrate communities at five impacted "restored" sites on the UBMC with ten unimpacted "reference" sites. I then quantified colonization using seven indices: four statistical taxonomic diversity and similarity indices, the River Invertebrate Prediction and Classification System (RIVPACS), the Benthic Index of Biotic Integrity (B-IBI), and a new Stable Isotopic Colonization Index (SICI) which estimated isotopic complexity using metrics derived from delta 15N and delta 13C stable isotopes. Statistical diversity and similarity indices showed the restored sites were diversifying quickly. For example, from 2020 to 2023, the average (+ or - 1SD) Shannon Diversity of restored sites increased from 1.1 + or - 0.5 to 1.8 + or - 0.43 while reference was 2.1 + or - 0.3. The average B-IBI of restored sites increased from 11.1 + or - 4.8 in 2020 to 31.7 + or - 7.7 in 2023 while reference B-IBI was 65.7 + or - 4.5, indicating ongoing ecosystem recovery, but this index required taxonomic identification to the genus level. The average SICI for restored sites was 23.3 + or - 6.1 and reference was 54 + or - 9.2, and SICI required identification to the family level. Restoration efforts on the UBMC have resulted in a promising trajectory, but continuous monitoring is imperative to ascertain if restored streams have reached reference conditions.
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    Ventenata (Ventenata dubia) control treatments on the Crow Reservation
    (Montana State University - Bozeman, College of Agriculture, 2023) Fighter, Zachariah Zachary Zane; Chairperson, Graduate Committee: Jane M. Mangold; Scott Powell (co-chair)
    Ventenata (Ventenata dubia) is a non-native winter annual grass that has been of increasing concern in southeastern Montana. Research has shown that ventenata can increase rapidly, lower forage production, and reduce biodiversity. This project is located in southeastern Montana, in Bighorn County on the Crow Reservation. Two studies were conducted to understand control options and monitoring of those treatments post-treatment. A field study tested two herbicides and a soil amendment for the management of ventenata. At four sites, indaziflam and imazapic at two water carrier rates and two rates of an organic soil nutrient amendment were tested using a split-plot randomized block design. The water carrier rates were meant to mimic aerial and ground applications. Herbicides were applied using a hand-held boom sprayer pressurized by CO 2. Soil amendment was hand-broadcasted. In late June 2022 (first growing season post-treatment), sampling consisted of randomly placing 3, 20 cm x 50 cm frames in each split-plot and estimating cover by species along with litter and bare ground. Imazapic and indaziflam provided the highest reduction of ventenata, regardless of water carrier rate. Across the four sites, imazapic reduced ventenata cover to <1% while indaziflam reduced cover to 4%, compared to the control which was 38%. The soil amendment reduced ventenata to 25% at two sites, suggesting it may not be as promising of a control method as the herbicides. Application rates for all treatments did not differ, suggesting that aerial application of the herbicides may provide just as good of control as ground application. This is encouraging for the prospect of managing ventenata aerially. At one of the sites, a remote sensing time series study using an Unmanned Aerial Vehicle (UAV) with a multispectral sensor was used to understand differences in the Normalized Difference Vegetation Index (NDVI) between herbicide sprayed and non-sprayed plots. Findings indicate that there is a shift in NDVI in late June where sprayed plots peak in NDVI and remain green longer into the season than non-sprayed plots. This study provides control options that land managers in southeastern Montana can consider using for ventenata management.
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