Theses and Dissertations at Montana State University (MSU)
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Item Breaking through: how documentary filmmakers expose and unravel the fossil fuel hegemony(Montana State University - Bozeman, College of Arts & Architecture, 2022) Dinner, Joshua; Chairperson, Graduate Committee: Theo LipfertBy analyzing contemporary environmental films within Antonio Gramsci's theoretical framework of hegemony, this MFA thesis highlights a path for storytellers and science communicators to overcome hidden barriers built into the language of environmental activism. Part one uses scientific papers, academic research, and my MFA thesis film 'No Time for Trees' (2022) to scrutinize the environmental stewardship activity of tree planting, which municipal governments and non-profit organizations often promote as a strategy to sequester atmospheric CO 2 emissions. It will contextualize the hegemonic "tree planting message" as a false narrative that empowers individuals to partake in ineffective strategies to combat global warming. Part two examines The 11th Hour (2007) to identify how a documentary's narration impacts how viewers assess their role in the environmental arena. It identifies the pronoun "we" as a small but influential element of the film's language that may connote hegemonic messaging that blames individuals for climate change and directs them to see it solved. Finally, part three examines several rhetorical film strategies used in 'Merchants of Doubt' (2014) to expose the fossil fuel industry's comprehensive history of deception. Even will limited visual evidence of hegemony, films can help viewers think critically about stories they hear in the news media or within publications that skew climate science to favor the continued use of fossil fuels.Item Exploring the role of water in tree growth and what trees can tell us about the hydroclimate of the past(Montana State University - Bozeman, College of Letters & Science, 2018) Martin, Justin T.; Chairperson, Graduate Committee: David Roberts; Jia Hu (co-chair); Nathaniel Looker, Zachary Hoylman, Kelsey Jencso and Jia Hu were co-authors of the article, 'Hydrometeorology organizes intra-annual patterns of tree growth across time, space, and species in a montane watershed' in the journal 'New phytologist' which is contained within this thesis.; Nathaniel Looker, Zachary Hoylman, Kelsey Jencso and Jia Hu were co-authors of the article, 'Differences in the use of winter precipitation by conifers along an elevation gradient in the northern Rockies' submitted to the journal 'Global change biology' which is contained within this thesis.; Gregory Pederson, Connie Woodhouse, Edward Cook, Gregory McCabe and Kevin Anchukaitis were co-authors of the article, 'Unprecedented drought intensity tracks recent warming in the headwaters of the United States' largest river basin' submitted to the journal 'Nature climate change' which is contained within this thesis.Here, we revisit the role of water potential in tree growth control using a field-based approach to exploring the role of soil moisture supply and atmospheric moisture demand on tree water potential and subsequently, growth. We explore how limitation in tree radial growth can be well predicted by local hydrometeorlogical conditions and associated tree water potentials, and observe that such limitation occurs under conditions that are considerably more mesic than those associated with the onset of photosynthetic limitation resulting from stomatal regulation (Martin et al., 2017). While direct observation of tree xylem growth and growth limitation remains a very challenging problem, our findings provide strong evidence for the role of Psi x in the regulation of tree radial growth in dry environments...Because one of the most prominent features of observed climate change in the American West has been an advancement in the timing of spring conditions (Cayan et al., 2001; Stewart et al., 2005), developing a better understanding of how the timing of moisture delivery and tree growth relate is an important research goal. Using a field-based study carried out over three years in western Montana, we quantified the timing and magnitude of moisture delivery to a forest ecosystem, and coupled this to isotope-based observations of where in the soil profile trees sourced water from as well as the seasonal evolution of radial growth. This allowed us to estimate the importance of winter precipitation relative to summer rains for growth in trees over the growing season. This work establishes a baseline understanding of how temporal dynamics of moisture delivery to forests and tree growth relate in time and can help guide our understanding of how ongoing changes to climate conditions may affect tree growth in the future...In order to better understand the hydroclimatic dynamics of the Missouri river, we developed a network of tree ring based reconstructions of streamflow spanning 1200 years for every major tributary across the mountain headwaters of the Missouri river. We examined the history of basin-wide drought events evident in the tree ring record in the context of reconstructed temperature and explored how the relationship between temperature and streamflow has changed over time. As a result, it is evident that rising temperatures create new challenges for water managers and users in the Upper Missouri River Basin that are likely to increase as temperatures warm in the future.Item Soil storage on steep forested and non-forested mountain hillslopes in the Bitterroot Mountains, Montana(Montana State University - Bozeman, College of Letters & Science, 2018) Quinn, Colin Aidan; Chairperson, Graduate Committee: Jean DixonMountain hillslopes are dynamic settings with discontinuous soils affected by a suite of variables including climate, lithology, hydrology, and vegetation. Our study seeks to understand how forest cover influences soil and rock distribution at decadal to century timescales. We focus on a series of post-glacial hillslopes in Lost Horse Creek of the Bitterroot Mountains, Montana. In this system, avalanche paths maintain parallel, topographically similar swaths of forested and non-forested slopes with uniform aspect, lithology, and climate. We combine field observations, fallout radionuclide analysis (210 Pbex & 137 Cs), and remote sensing data to understand both landscape- and fine-scale patterns in soil and rock distribution. Local soil and rock measurements indicate more extensive soil cover (forest = 94.4 + or = 2.6%; non-forest = 88.3 + or = 1.9%) and thicker soils (6cm greater median) in the forested system. We compare landcover-classified rock to topographic metrics from LiDAR data and find a doubling of rock cover (from 40% to 80%) as hillslope angles transition across slopes of ~24-42 ?. Topographic roughness, calculated as the standard deviation of slope, is predictive of only ~60% of total landscape rock cover, but can identify large boulders and coarse-scale outcrops with higher accuracy (79%). These calibrated remote sensing metrics indicate higher rock cover in non-forested regions (34%, compared to 20% in forested areas), though with high uncertainty. Additionally, we measure fallout-radionuclide inventories in soils to explore variations in decadal transport processes and soil residence times. We find distinct 210 Pb and 137 Cs behaviors in forested and non-forested systems, controlled both by unique partitioning of each nuclide within organic and mineral soil horizons, but also due to depth-driven differences in their physical mobility. Average 210 Pb ex inventories in non-forested soils are 33% lower, and half as variable as soils in the forested region (10.45 + or = 0.97 and 15.49 + or = 1.91 kBq/m 2 respectively), while 137 Cs inventories are indistinguishable (4.04 + or = 0.34 and 3.73 + or = 0.42 kBq/m 2). Together, our spatial, field, and isotope analyses suggest forested systems have greater soil storage and longer residence times than non-forested soils, mediated by differences in surface erosion processes within a larger fire disturbance landscape.Item The average length of freeze-free season as an index to woody ornamental plant hardiness(Montana State University - Bozeman, College of Agriculture, 1971) Murphy, J. L.Item Natural modeling of quaking aspen(Montana State University - Bozeman, College of Engineering, 1993) Spear, Rita SteeleItem A synecological study of the forested moraines of the valley floor of Grand Teton National Park, Wyoming(Montana State University - Bozeman, College of Agriculture, 1966) Oswald, E. T.Item Temporal accumulation and ablation patterns of the seasonal snowpack in forests representing varying stages of growth(Montana State University - Bozeman, College of Letters & Science, 1990) Hardy, Janet PhillipsItem Long-term perspectives on northern Rockies climatic variability from tree rings in Glacier National Park, Montana(Montana State University - Bozeman, College of Agriculture, 2004) Pederson, Gregory Thomas; Chairperson, Graduate Committee: Lisa J. Graumlich.Instrumental climate records reveal fluctuations in summer moisture anomalies and winter snowpack in Glacier National Park, Montana, on decadal and multidecadal timescales. However, because climate records for the region are limited to the 20th century, studies on the impacts of long-duration variations in climate on physical and ecosystem processes were limited. Therefore, a reconstruction of summer moisture variability (June - August) spanning A.D. 1540-2000 was created from a multi-species network of tree-ring chronologies sampled in Glacier National Park. The reconstruction shows decadal-scale shifts between drought and pluvial events with a pronounced cool/wet period spanning the end of the Little Ice Age (A.D. 1770-1840). The single most exceptional drought event occurred over the 20th century (A.D. 1917-1941) and was associated with the most spatially consistent drought regime throughout the northern Rockies and Pacific Northwest over the past ~500 yrs. Among a wider spatial network of hydroclimatic reconstructions arrayed along a north-south Rocky Mountain transect, trends at Glacier National Park were found to be most similar to those in the Canadian Rockies and the Pacific Northwest.