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Item 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. EwingHydrogeologic 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.Item Rural gentrification(Montana State University - Bozeman, College of Arts & Architecture, 2021) Matty-Huber, Cynthia; Chairperson, Graduate Committee: Dennis AigRepresentations and studies of gentrification largely focus on its impact in urban centers. Urban gentrification brings change in an urban area associated with the movement of more affluent individuals into a lower-class area. However, rural gentrification has been overlooked in documentary representations of gentrification. Rural gentrification occurs when wealthier people buy property in ranch and working-class areas, driving up property values. Both contexts share the difficult paradox that gentrification brings money into the impacted area, but it often comes at the expense of poorer, pre-gentrification residents who cannot afford increased property costs or taxes. The mountainous west of the United States has been an area of intense development in recent decades and many aspects of its character have changed with shifting demographics as a result of rural gentrification. This thesis, titled 'Rural Gentrification,' examines the unique role of documentary film in demonstrating the impact of rural gentrification through the eyes of, John Hoiland, one of Montana's last independent ranchers, who is the subject of my film 'For the Love of Land'. The film tells the story of finality, disappearance, and what it means to be the last of something in this rapidly-shifting terrain while bringing attention to that tragic position that these last remaining personalities of the old west find themselves in as the world around them changes. 'Rural Gentrification' argues that there is an urgent need to create visual representations of the mountainous west of the United States using documentary film against this backdrop of rapid change. Using 'For the Love of Land' as a case study, I trace the significance of observational cinema as a significant influence that informed the decision-making process and creation of the film.Item Understanding hydrogeomorphic influences on stream network denitrification and temperature dynamics(Montana State University - Bozeman, College of Agriculture, 2020) Carlson, Samuel Paul; Chairperson, Graduate Committee: Geoffrey PooleThe removal of nitrate from stream networks through the process of denitrification is an important component of local and regional nutrient cycles, but the controls on stream network denitrification rates remain poorly understood. Previous work has demonstrated general effects of stream channel size and nitrate loading rates on network-scale denitrification rates, but has been unable to elucidate connections between the complex environmental template of streams, and resulting denitrification rates. Understanding links between land use and management practices, physical characteristics of streams, and stream denitrification rates is critical to interpreting observed patterns of nitrate in freshwater systems and forming holistic management strategies for reducing the negative effects of elevated nitrate concentrations. To address these critical uncertainties, I developed a stream network simulation model that incorporates the effects of whole-stream aerobic respiration on biotic denitrification demand. This model is applied to a small, subalpine stream network under scenarios designed to explore: 1) the implications of temperature-controlled, network scale patterns of respiration rates on the distribution and overall magnitude of stream network denitrification, and 2) the effect of logging-induced channel simplification on whole network denitrification rates. The first analysis is complimented by an evaluation of controls on stream temperature across this network, revealing the spatially and temporally variable influence of in-network lakes on stream temperatures. Results from the first analysis suggest that reach- and network-scale denitrification rates are strongly influenced by respiration rate and temperature when nitrate supplies are high relative to removal rates, indicating an increased contribution of lower, warmer streams to whole-network denitrification. The second analysis reveals that historical logging has caused a ~30% loss of stream network denitrification capacity, which is manifested as a corresponding reduction in whole-network denitrification rates when nitrate supplies are not limiting. In sum, this work emphasizes the diverse set of factors that influence reach- and watershed-scale biogeochemical characteristics and processes, and suggests that land management actions which influence stream morphology may also alter stream denitrification rates.Item Investigating the impacts of agricultural land use change on regional climate processes in the northern North American Great Plains(Montana State University - Bozeman, College of Agriculture, 2021) Bromley, Gabriel Trees; Chairperson, Graduate Committee: Paul C. Stoy; Jack Brookshire (co-chair); Tobias Gerken, Andreas F. Prein and Paul C. Stoy were co-authors of the article, 'Recent trends in the near-surface climatology of the northern North American Great Plains' in the journal 'Journal of climate' which is contained within this dissertation.; Andreas F. Prein, Shannon Albeke and Paul C. Stoy were co-authors of the article, 'Simulating the impacts of agricultural land use change on the climate of the northern North American Great Plains: validating a convection-permitting climate model' submitted to the journal 'Climate dynamics' which is contained within this dissertation.; Andreas F. Prein, Shannon Albeke and Paul C. Stoy were co-authors of the article, 'The decline in summer fallow in the northern plains cooled near-surface climate but had minimal impacts on precipitation' submitted to the journal ' ' which is contained within this dissertation.; Andreas Prein and Paul C. Stoy were co-authors of the article, 'Recent enhancement of thermodynamic environments in the northern North American Great Plains' submitted to the journal 'Geophysical research letters' which is contained within this dissertation.The northern North American Great Plains (NNAGP) is the area defined by the Upper Missouri River Basin and the Canadian Prairies. It is a semi-arid region categorized by large stretches of grassland, pasture, and crops. During the last century and extending to the present day, a standard agricultural practice was to utilize a wheat-summer fallow rotation schedule, where the fields were left unplatted and an herbicide was often applied to keep weeds at bay. Concerns over soil health and profitability have led to the systematic decline of summer fallow, and nearly 116,000 km 2 that used to be fallow during the summer in the 1970s are now planted. An observational analysis discovered that from 1970-2015, during the early warm season, the NNAGP have cooled at -0.18 °C decade -1, nearly the same magnitude as the annual global warming rate. The near-surface atmosphere also moistened, evidenced by a decreasing vapor pressure deficit (VPD) trend, and monthly mean precipitation increased in excess of 8 mm per decade. Monthly mean convective available potential energy (CAPE) increased by 80% at Glasgow, MT and by 35% at Bismarck, ND based on atmospheric sounding observations. To test whether a reduction in summer fallow is responsible for these observed changes, a set of convection-permitting model experiments were performed over the NNAGP. Two sets (4 total) of three-year simulations were driven by ERA5 data with the vegetative fraction adjusted using satellite estimated fallow amounts for 2011 and 1984. The control simulations were extensively validated against an ensemble of observations with large temperature biases in Winter by ~ -3 °C and Summer by ~3°C. The areas where fallow area declined from 1984-2011 were cooler by about 1.5 °C and had a lower VPD by 0.15 kPa compared to where it did not. CAPE increased where fallow declined from 1984-2011 but so did convective inhibition (CIN). These findings insinuate that the observed change to monthly mean precipitation cannot be explained by summer fallow reduction alone. Trends in observed low level moisture transport show that the Great Plains Low Level Jet has been intensifying, bringing increased moisture to the NNAGP and partially responsible for the precipitation increase.Item Evaluating the land: evolving perceptions of landscape in Gallatin Valley settlement, 1864-1918(self-published, 1997-05) O'Neill, MaireThis study investigates how people have viewed the environment and the terrain of the Gallatin Valley through a cross section of time. The period during which the region was settled is explored for its impact on the present palimpsest of the landscape. The choices people made about where to farm and where to site their houses reveals much about their perceptions and attitudes towards the land. What people thought about its potential and its threats are reflected not only in their journals, but in the physical markings they have made in the form of buildings, fences, roads, and irrigation ditches.Item The role of land use change and land management in the global carbon cycle: simulation as a test of process understanding(Montana State University - Bozeman, College of Letters & Science, 2019) Calle, Leonardo; Chairperson, Graduate Committee: David Roberts and Benjamin Poulter (co-chair); Josep G. Canadell, Prabir Patra, Philippe Ciais, Kazuhito Ichii, Hanqin Tian, Masayuki Kondo, Shilong Piao, Almut Arneth, Anna B. Harper, Akihiko Ito, Etsushi Kato, Charlie Koven, Stephen Sitch, Benjamin D. Stocker, Nicolas Vivoy, Andy Wiltshire, Sonke Zaehle and Benjamin Poulter were co-authors of the article, 'Regional carbon fluxes from land use and land cover change in Asia, 1980-2009' in the journal 'Environmental research letters' which is contained within this dissertation.; Prabir Patra and Benjamin Poulter were co-authors of the article, 'A segmentation algorithm for characterizing rise and fall segments in seasonal cycles: an application to XCO 2 to estimate benchmarks and assess model bias' in the journal 'Atmospheric measurement techniques discussions' which is contained within this dissertation.Humans have left their mark on Earth's ecosystems for centuries. Since 1900, the human population has grown more than 400%. Land conversion and land management have helped meet an ever-increasing demand for natural resources. Forests have been cleared for agriculture, grasslands have been used for grazing by farmed animals, and extensive logging activity has provided fuelwood for energy and raw materials for building. But a long history of land management has also led to a change in forest production, leaving century-old legacies of human activity on Earth's ecosystems. As land is deforested, wood can be used for building or other products. Unused biomass can be burned for fuel or naturally broken down by microbes into soils, ultimately being converted to carbon dioxide. This phase conversion of carbon, from solid to gas, is a natural process but humans have sped up this process, leading to more carbon dioxide in the atmosphere than would otherwise occur naturally. Increasing levels of carbon dioxide in the atmosphere is a direct cause of increasing global temperatures and changes to regional climates. For these reasons, the focus of research in this Dissertation has been to track each and every process during land use change and land management, to provide a better accounting of where and how much carbon gets transferred from solid to gas during land use activities, and to identify any alteration to the productivity of ecosystems long after timber harvest has removed wood for products or agricultural lands have been abandoned and the forest allowed to regrow. The research papers in Chapter Two and Three have been published in peer-reviewed scientific journals, and Chapter Four is prepared for submission for publication. Each chapter focuses on a very specific problem, but the thread connecting all these works is carbon -- How much carbon is transferred to a gas when natural lands are modified and resources extracted to meet human demand? Does deforestation leave a unique and long-lasting signal in the atmosphere? Land management creates more young, fast-growing forests, but can models represent forests of different ages at global scales?Item Disentangling anthropogenic and natural drivers of change in vegetation and fire history along the forest-grassland ecotones of the central United States and Patagonia(Montana State University - Bozeman, College of Letters & Science, 2020) Nanavati, William Parashar; Chairperson, Graduate Committee: Cathy Whitlock; Eric C. Grimm was a co-author of the article, 'Humans, fire, and ecology in the southern Missouri Ozarks' in the journal 'The holocene' which is contained within this dissertation.; Cathy Whitlock, Valeria Outes and Gustavo Villarosa were co-authors of the article, 'A holocene history of Araucaria araucana in northernmost Patagonia' submitted to the journal 'Journal of biogeography' which is contained within this dissertation.; Cathy Whitlock, Virginia Iglesias and Maria Eugenia de Porras were co-authors of the article, 'Postglacial vegetation, fire, and climate history along the eastern Andes, Argentina and Chile (lat. 41-55°S)' in the journal 'Quaternary science reviews' which is contained within this dissertation.Disentangling anthropogenic and natural drivers of vegetation and fire history at different spatiotemporal scales is a fundamental challenge in Earth Systems science. To better understand the role of past human ignition in altering long-term ecosystem dynamics, we rely on the anthropogenic fire regime conceptual model proposed by Guyette et al. (2002) in the central U.S. Ozarks. The synthesis of new and existing pollen and charcoal records, and their integration with archaeological, ethnographic, and independent paleoclimate records is used to test the anthropogenic fire regime conceptual model at a longer time scale in the central U.S. Ozarks. Following its validation, this conceptual model is applied to the forest-steppe ecotone east of the Patagonian Andes (38-55°S) for the first time. Although it is well established that Patagonian vegetation and fire history for most of the postglacial period was governed by the strength and position of the Southern Westerly Wind (SWW) storm tracks, the influence of land use since the arrival of American Indians to the region ~12,000 years ago remains unclear. From the late glacial to early Holocene, region-wide increases in fire were associated with aridity while the SWW were weakened and south of their present position. Between ~7000-4000 cal yr BP, increased arboreal taxa and decreased fire throughout Patagonia suggest wet conditions as the SWW moved northward to their present position. After ~4000 cal yr BP, a combination of increased land use and greater climate variability, led to spatially heterogeneous but generally rising fire activity along the forest-steppe ecotone. When trends in the vegetation and fire history of individual sites are compared to each other and to the archaeological record, however, it becomes apparent that American Indians may have served as an important source of ignition, locally increasing landscape heterogeneity since their arrival. During the last 100 years, increased Euro-American settlement and land clearance in Patagonia led to native forest loss, more disturbance, and the spread of introduced taxa along the eastern flanks of the Andes. These ecological changes in the recent century far outweigh thousands of years of American Indian influence on fire and vegetation history.Item American Zion: Mormon perspectives on landscape from Zion National Park to the Bundy family war(Montana State University - Bozeman, College of Letters & Science, 2017) Quammen, Betsy Gaines; Chairperson, Graduate Committee: Michael ReidyThis dissertation is about Mormon views on landscape and resource use from Euro-American settlement in what is today southern Utah and southeastern Nevada, to the current range battles over public lands. In journals, articles, interviews, videos, and blog posts, a record of grazing and extraction during early settlement through the opening of tourism and modern federal management exists; these materials portray religious and utilitarian views on landscape and justify land use accordingly. Opinions over the appropriate use of federal lands, cultural biases and differing notions of ownership present a wide disparity on regional and national perceptions of suitable uses of federal property. Most urban Americans want to access public lands for reasons other than resource extraction. Western ranchers and their supporters, on the other hand, want to use public land for economic purposes. A group of Mormon ranchers justify their position through ancestry, entitlement and religious beliefs. The result has been a protracted conflict, in Mormon homeland, between the federal government, regional residents and the broader American public. This dissertation tracks early land use by Southern Paiute and Mormons; the history of grazing on federal lands and the establishment of national parks and monuments in Mormon country; and current armed conflicts over land use.Item The effect of organic certification on farmland value(Montana State University - Bozeman, College of Agriculture, 2017) Boldbaatar, Munkhnasan; Chairperson, Graduate Committee: Joseph JanzenThis research considers the relationship between organic certification and farmland values. We employ the ARMS survey data from 2003 to 2011. We construct three models with different organic status classifications. We control for differences in farm type, NASS crop district, urbanization, and year fixed effects. We find that organic certification has a significant (statistically and economically) effect on farmland value. Our model suggests that a 1 percentage point increase in a farm's organic land would result a 0.23 percentage point increase in the farmland rental rate.Item A multi-use facility in Anchorage, Alaska : point resolution(Montana State University - Bozeman, 1986) Wolf, Gary; Chairperson, Graduate Committee: Clark E. Llewellyn