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  • Thumbnail for Coccinellid predation on Aphis helianthi : diffusive instability and pattern formation in predator-prey systems
    Coccinellid predation on Aphis helianthi : diffusive instability and pattern formation in predator-prey systems by Kidney, Daniel

    Spatial context in predator-prey systems has proven to have important dynamical consequences. Instabilities and spatial pattern formation driven by diffusion (Turing pattern formation) have been extensively observed and theorized on, but empirical examples of Turing pattern formation in ecological systems are few. In this study we construct and analyze a reaction-diffusion equation model of the aphid species Aphis helianthi under predation by two species of ladybugs: Coccinella septempunctata and Hippodamia convergens. The structure and parametrization of the model is entirely field derived and in analysis of model output it is compared extensively to field observations. This system fits the well known framework for diffusive instability and pattern formation: an activator-inhibitor system in which the inhibitor (predator) diffuses substantially faster than the activator (prey). Theory predicts that under these conditions the inhibitor will fail to strike a normal equilibrium with the activator; rather diffusing away from activator outbreaks too quickly to contain them, subsequently over-inhibiting the surrounding lower densities of activator (undermatching). This usually results in a patchy, bimodal distribution of prey resulting from cubic density dependence driven by undermatching. Aphid population distribution in the field is clearly bimodal and patchy. We looked for several indications of diffusive instability in field data; bimodality, cubic density dependence, and undermatching were all found. The focus of this paper is on a mathematical model we developed from field data to gain insight into the workings of the system. I found the model matched field data very well and corroborated the hypothesized functioning of a diffusive instability. I explored the role of self attraction (aggregation) among ladybugs. Aggregation is not considered a hallmark of diffusive instability but in this case it created some preytaxis in ladybugs (allowing aphids to act as an activator). Preytaxis by aggregation is slow though, which allowed some aphid populations to avoid detection long enough to reach the high attractor of cubic density dependence. Finally I considered the nature of space in our system. Although our model is constructed in Euclidean space it demonstrates some features of a network. Network structured systems manifest Turing patterns primarily as bimodal distributions. They also facilitate understanding of ladybug behavior and may increase efficiency of computer model execution.

  • Thumbnail for Rethinking "Wild" and Shifting the Management Paradigm: Facilitating 21st Century Conservation through the BLM's Wild Horse Program
  • Thumbnail for Characterization of secondary organic aerosol formed from pyruvic acid photolysis
    Characterization of secondary organic aerosol formed from pyruvic acid photolysis by Severson, Rachel

    Pyruvic acid is ubiquitous in the atmosphere and currently used as a proxy for similar molecules in climate models. We produced secondary organic aerosol (SOA) from the aqueous photolysis of pyruvic acid, and aerosol yield and cloud condensation nuclei (CCN) activity was measured. Aqueous samples were atomized to obtain the volume of aerosol produced per volume of initial pyruvic acid (aerosol yield) and the hygroscopicity parameter (κ) was determined. At room temperature (21°C), unreacted pyruvic acid was atomized to yield ~ 4% aerosol with κ = 0.22. Significant formation of aerosol from unreacted volatile pyruvic acid implicates the potential involvement of self-oligomerization via hemiketal formation. After photolysis, a 0.1 M aqueous sample of pyruvic acid led to an increased aerosol yield of ~ 15%, and a decrease in κ to 0.13. This decrease in κ after photochemical aging is in contrast to conventional hypotheses regarding in-cloud SOA formation, which generally predict an increase in hygroscopicity. The potential roles of variable environmental conditions in SOA formation were also investigated. Pyruvic acid photolysis carried out at 15°C, pH 2 and 21°C, pH 7 gave a decrease in κ from 0.2 to 0.13, and from 0.22 to 0.12, respectively. At pH 7, photolysis resulted in a lesser increase in aerosol yield from ~ 6% to only 10%; aerosol yield increased in the 15°C condition from 5 to 18%. These results support the importance of further investigation of SOA formation and composition, and of the effects of fluctuating environmental conditions—these effects are not currently well understood, but are likely important on a global scale.

  • Thumbnail for East, West, and Back: The Path of Gary Snyder
    East, West, and Back: The Path of Gary Snyder by Stein, Thomas Jacob

    This paper will address two closely linked lines of inquiry, the first of which is how the living practice of Zen Buddhism might work to deepen an ecological understanding of the world by fostering a deeper understanding of the self and the place of the self in the wider sphere of the inherent interconnectedness of the natural world. The second question is: How might the path of Gary Snyder be an example to which American environmentalists might look in order to bring greater meaning and understanding to the practice of what is conventionally termed “environmentalism.” These questions will bring about discussion of the potential problems with Western dualism that might be countered by the nondualist tradition of Zen Buddhism. With this context established, we will examine the trajectory of the work of Gary Snyder and how the practice of Zen Buddhism broadened his understanding of themes already present in his American naturalist roots. In this paper I focus on two important gleanings from Zen Buddhist practice and teaching, the first of which is the idea of a dependent self that is inherently part of the interconnected sphere of living and nonliving things here on this earth and extending outward into the entire universe. This Buddhist view of self allows for a wider scope that works against the restrictions placed on the self by the dominant Western notion of an independent and autonomous self. Snyder’s sense of interconnectivity can be seen to develop throughout the trajectory of his poetry and prose, coevolving with his understanding of self as it is informed by his Zen practice. The second takeaway I hope will be the grounding effects of Zen practice, allowing the practitioner to focus on the task at hand, effectively eliminating mind-body dualism that can be shown to extend to a problematic and hierarchical human-nature dualism. I will examine this idea of undivided attention to the task at hand as Gary Snyder has emphasized this aspect of his Buddhist and naturalist practice throughout the course of his life and works. An American naturalist, poet, activist, and Zen practitioner, Gary Snyder supplements Western ecological thought with indigenous and Eastern wisdom. He effectively draws from each tradition to add to his practice of living lightly on this earth. Snyder has cultivated a worldview in which interconnectivity is inherent and every action is done in mind of a larger whole, no doubt owing to his involvement with Zen practice. It is my goal in writing this paper to examine, by the example of the life and writing of Gary Snyder, how certain aspects of environmentalism, speaking both philosophically and practically, might be given greater meaning and depth through the nondualist practice of Zen Buddhism.

  • Thumbnail for An exploratory study of the vertical growth of trees at the alpine treeline of Pike's Peak, CO
    An exploratory study of the vertical growth of trees at the alpine treeline of Pike's Peak, CO by Marks, Rebecca L

    Vertical growth is an important element to consider when evaluating the movement of an alpine treeline. The vertical growth of trees is decisive in the establishment of trees upslope of the existing treeline, as trees must be able to grow up, mature, and reproduce in order for the treeline to advance. The purpose of this study was to explore the possible causes of, and factors influencing, the vertical growth of trees in a treeline environment, specifically at the alpine treeline of Pike’s Peak, CO. Vertical growth was first studied on an individual scale, specifically investigating the thermal regime of trees and its impact on growth. The air temperature profile showed a nighttime inversion of daytime conditions. During the night there was a lapse rate of approximately 1°C, with the coldest conditions closest to the ground. Thus, the smallest trees were in significantly colder environments during the night than the largest trees. During the day, there was a lapse rate of approximately 3°C per meter, a very high lapse rate, with the warmest conditions occurring closest to the ground. Thus, the smallest trees were in the warmest conditions throughout the day. Additionally, it was found that small trees were coupled to ground conditions during the day as well as the night, and that the taller trees were coupled to atmospheric conditions. Yet, the coupling relationships were not exact, as the tree temperatures never exactly matched the ground or atmospheric temperatures. Finally, I investigated whether daytime or nighttime temperatures impacted growth more closely. It was found that daytime conditions were more important for the growth of trees at the study site on Pike’s Peak. The second part of the study investigated tree growth on a stand-wide scale, considering whether or not there were larger spatial patterns affecting the vertical growth of trees. I found that a shelterbelt-like system was in place at the treeline, the presence of which seemed to be affecting the growth of the trees within its bounds. Specifically, there was depression of growth directly upslope of the trees creating the upper bounds of the treeline, then an area of facilitated growth, ending with a return to normal conditions. Yet, these shelterbelt conditions were only detected for trees one meter or taller. The growth patterns for trees under 1 meter did not correlate to the growth patterns of taller trees. Additionally, the shelterbelt conditions would only be present during the day, which further confirms the importance of daytime conditions found in the first study. This exploratory study was a first look into the drivers of vertical growth of trees at an alpine treeline.

  • Thumbnail for Carbon fluxes in the SiB3 model : evaluating the response of the terrestrial biosphere to significant drought
    Carbon fluxes in the SiB3 model : evaluating the response of the terrestrial biosphere to significant drought by Shiach, Ian Michael

    This study investigated the behavior of the terrestrial biosphere during times of significant drought, particularly in regard to carbon fluxes. The Simple Biosphere Model Version 3 (SiB3) was used to facilitate an investigation of ecosystem drought response. The Standardized Precipitation Index (SPI) was evaluated from 1983 to 2006 in order to produce historical drought maps, which were used to facilitate a subjective analysis of drought behavior and to identify geographic point locations in the SiB3 model for further temporal study. Standardized maps were produced for modeled physiological variables (gross primary productivity, respiration, net ecosystem exchange, and soil water stress factor) over time in order to determine general regional drought response patterns. Physiological response variable data for particular spatial locations was then analyzed over time during drought years for anecdotal comparison with observational study data. While the SPI, which standardizes precipitation, was predicted to be an indicator of ecosystem drought response, this did not appear to be the case. The droughts modeled in the SiB3 model, which included the droughts in the United States Southwest and Australia in 2002 and in Europe in 2003, were found to respond heterogeneously in terms of carbon fluxes to similar droughts. The U.S. Southwest and Australia appeared to respond to drought in a manner consistent with anecdotal evidence with regard to perturbations in gross primary productivity (GPP), ecosystem respiration, and net ecosystem exchange (NEE), while Europe appeared to respond in a manner dissimilar to published descriptions of that drought. The behavior of the soil water stress factor in Australia and Europe seemed to be incorrect as well. Precipitation input data, derived from a reanalysis dataset from the National Centers for Environmental Prediction (NCEP), the treatment by the SiB3 model of the soil water stress factor, and the possible heterogeneous vegetative response to seasonality between regions were identified as potential causes of these disparities.

  • Thumbnail for Collaborative Conservation in the Contested Landscapes of Southern Utah
    Collaborative Conservation in the Contested Landscapes of Southern Utah by Larsen, Judy Brooke

    As the West has grown and urbanized, a clash has formed between the Old West and New West—between traditional, rural livelihoods such as ranching and mining and those of the growing service sector and recreational economy. However, the complex history of Western landscapes and the current mix of diverse stakeholders show that the conflict goes beyond this binary. Conventional methods of large landscape conservation can heighten contention, so collaborative conservation has emerged as an alternative strategy. This paper discusses Southern Utah as a contested landscape, and assesses the viability of collaborative conservation to reduce contention in the region and conserve large landscapes. To identify factors that make Southern Utah contested, I conducted a historical analysis of federal land policy and major conservation events and land disputes in Southern Utah, and I interviewed 37 people, including stakeholders, experts, federal agency workers, and elected officials. I then assessed four case studies of collaborative conservation in Southern Utah. I found seven characteristics important for collaborative conservation processes: unifying crisis, funding, leadership, expert facilitator, appropriate scope, consensus, and reciprocity. I also assessed the outcomes of each case study in terms of improved environmental health and improved relations and trust among stakeholders and managers (Kinney 2001). I found that Southern Utah is an inherently contested landscape that poses challenges to substantively conserve large landscapes while also reducing contention. Collaborative conservation is a viable conservation strategy under the circumstances I identified, but the success of the collaboration can vary depending on the goals and methods used in the collaboration.


    The “institutional inertia” for Education for Sustainability (EfS) in liberal arts institutions is often attributed to faculty perceptions that EfS is not relevant within their area of expertise. However, sustainability is most effectively integrated into an institution when the formal administrative structures align to prioritize a whole system approach. After conducting 40 interviews with professors across all divisions, we developed an understanding of academics’ attitudes, values, and experiences to identify areas where EfS can be more effectively woven into informal campus activities and curricula. In addition, the formal administrative structures of Higher Education Institutions (HEIs) can promote incongruences between faculty beliefs and campus practices. Findings from this qualitative study are divided into three hypotheses that a liberal arts education should: (1) transition away from teaching within disciplines and establish curricula structured around the process of learning, the development of skills, and the acquisition of knowledge through transdisciplinary topics, (2) create a context for student learning that engages the affective domain and fosters opportunities to develop individual values, attitudes and passions, (3) prioritize a process of learning that includes active participation and an inquiry-based approach to develop students as leaders and agents of change.  

  • Thumbnail for Conserving biodiversity : a qualitative method for analyzing federal environmental policies in the Greater Yellowstone Ecosystem
    Conserving biodiversity : a qualitative method for analyzing federal environmental policies in the Greater Yellowstone Ecosystem by Williams, Samuel Parker

    Biological diversity includes the variance in genes, organisms, and relationships found in nature. Also called biodiversity, it provides countless economic, social, and personal benefits to people in the United States and all over the world. In the U.S., this is recognized by the federal government most explicitly in the Endangered Species Act’s protections for those flora and fauna whose survival is least likely and most endangered by human action. Unfortunately, there are many anthropogenic threats to biological diversity. In order to protect this incredible natural resource, responsible management must be implemented across all levels of government. Given the amount of funding, large spatial scales, and public interest at stake, the federal government is the best suited to this task. The federal government must play a key role in the protection of biological diversity. The purpose of this paper is to provide a qualitative analysis of the federal government’s management of biological diversity in the Greater Yellowstone Ecosystem. Examining management at these scales is uncommon, yet extremely valuable. By examining management on scales that coincide with the scale of natural processes, we can better see the broad implications and interactions of our management policies. We can also determine how to sharpen management in order to more accurately address these important scales. In order to achieve this, a basic overview of modern conservation science and terms to be utilized will be provided. Building upon this overview, four categories will be describe, which, according to the science, are vital to the preservation of biological diversity. These categories are cores, connectivity, restoration, and monitoring. There will be three standards used to assess the quality of policy. Scientific foundations, the human-nature nexus, and adaptability are these three measures. The Greater Yellowstone ecosystem will then be described. Finally, in each of the four categories, examples of policy or management action will be described and analyzed via the three measures of successful policy. This analysis shall provide examples of policies with varying degrees of success. By extrapolating management from these representative case studies, an aggregate picture of management across the ecosystem will be gained. It is hoped that such analysis will uncover areas where management may be improved and facilitate the spread of successful policies and management ideas. It is also intended as a suitable framework for examining and creating biodiversity management policies in other ecosystems, regions, and countries.

  • Thumbnail for Tread lightly : an assessment of researcher trampling impacts on the understory vegetation of Lake Wabikon Forest Dynamics Plot
    Tread lightly : an assessment of researcher trampling impacts on the understory vegetation of Lake Wabikon Forest Dynamics Plot by Ede, Alena Corin

    Long term and large-scale ecological studies often require intensive sampling and replication. However, the inevitable impacts resulting from intensive researcher activity are often considered negligible and largely ignored in data analysis and interpretation of ecological data. This thesis study examines the impact of researcher trampling activity on the density and diversity of understory fern and woody seedling communities in a northern temperate forest research plot in Northern Wisconsin. I established thirty 1X1 m plots in heavily trampled, moderately trampled, and untrampled locations on and near the Wabikon Lake Forest Dynamics Plot. Fern and woody seedlings were identified to species, and fern species richness and Shannon’s diversity scores for woody seedlings analyzed for each plot and across trampling treatments. Fern and woody seedling diversity varied significantly with trampling intensity (ferns: Chi 2 = 9.772, df = 2, p = 0.008; woody seedlings: Chi 2 = 10.546, df = 2, p = 0.005). Decreases in fern density occurred between control and moderately trampled (MW = 269.000, WW = 734.000, p = 0.006) and between control and heavily trampled locations (MW = 283.500, WW = 784.500, p = 0.012), however moderately and heavily disturbed locations did not vary significantly in fern density (MW = 405.500, WW = 870.500, p = 0.485). Overall seedling density showed no significant variation between trampling treatments, however individual species assessments of Acer saccharum and Fraxinus americana seedlings indicate a significant decrease between trampling treatments for both species. Fraxinus americana seedling density decreased significantly control and moderately trampled (MW = 306.000, WW = 771.000, p = 0.031) and control and heavily trampled plots (MW = 317.500, WW = 782.500, p = 0.047), with no significant decrease between moderately and heavily trampled plots (MW = 436.000, WW = 901.000, p = 0.832). Conversely, Acer saccharum seedlings did not decrease significantly between control and moderately trampled plots (MW = 440.500, WW = 905.500, p = .874), but decreased significantly between control and heavily trampled (MW = 310.000, WW = 775.000, p = 0.008) and between moderately and heavily trampled locations (MW = 322.500, WW = 787.500, p = 0.013). Significant reductions in density and diversity of understory communities suggest that researcher activity can significantly alter a study ecosystem. This has both ecological and ethical implications, as researcher-induced alterations to understory composition may bias ecologists’ understanding of ecosystem dynamics and ecosystem response to environmental change.

  • Thumbnail for Size-Resolved Aerosol Composition near Rocky Mountain National Park
    Size-Resolved Aerosol Composition near Rocky Mountain National Park by Sussman, Rachel

    Increasing our understanding of aerosol properties is important because of their potential impacts on visibility, human health, and sensitive ecosystems. The Rocky Mountain Airborne Nitrogen and Sulfur (RoMANS) study was conducted in 2006 to identify the sources, transport, and speciation of atmospheric gases and aerosols throughout Colorado that influence Rocky Mountain National Park (RMNP). As one component of this study, Micro-Orifice Uniform Deposition Impactor (MOUDI) samples were collected at two sites in the vicinity of RMNP. Samples were taken over a time span of 48 hours each during a period of 36 days in the spring (March-April) and summer (July-August). The samples were analyzed by ion chromatography to determine the concentrations of NH4+, Na+, Ca2+, K+, Mg2+, Cl-, NO2-, NO3-, SO42-, and C2O42- in either ten or twelve different size bins from >18 μm to <0.18 μm. The diameter of nitrate has important implications for nitrogen deposition in RMNP as larger particles have a higher deposition velocity. In the spring, nitrate was observed to be mainly in the accumulation mode while in the summer it was primarily in the coarse mode. Ammonium and sulfate were the dominant species in the accumulation mode and on several days the sulfate was sufficient to completely neutralize ammonium. However, there were a substantial number of days where the addition of nitrate and oxalate to the ammonium neutralization was not enough to account for complete neutralization. The excess ammonium suggests that other organic acids may be an important component of the aerosol in the region. There is a dearth of research on the size distribution and secondary formation pathways of organic acids, such as aerosol oxalate, which might be contributing to haze and acting as cloud condensation nuclei. The size distribution of oxalate was found to peak in the accumulation mode, specifically between 0.32 and 0.56 μm. We examined three potential contributors to oxalate concentrations: biomass burning, in-cloud processes, and gas-phase photo-oxidation. All three were found to be likely emission and formation mechanisms, but it is unclear which pathway is dominant.

  • Thumbnail for Examining the Impact of the Northward Migration of Yellow Cedar on Ecosystem Biogeochemistry and the Net Carbon Equilibrium
    Examining the Impact of the Northward Migration of Yellow Cedar on Ecosystem Biogeochemistry and the Net Carbon Equilibrium by Jurney, Patrick

    Abstract: Yellow Cedar is an ecologically, culturally, and commercially important tree species; its habitat extends 20° in latitude from Southeast Alaska to the Northern California. It is experiencing extensive decline in areas of low elevation, latitude, and drainage capacity. This decline is due largely to climate change decreasing the snowpack, resulting in root-freezing injuries. Future climate change will place even the northernmost reaches of its range in conditions conducive to mortality by the end of the 21st century, putting Yellow Cedar on a path towards extinction. As vast areas of Yellow Cedar forest experience mortality, the species is also slowly migrating north to newly suitable habitat. Its northward migration is hampered by meager dispersal capability and its niche traits which limit its competitiveness to marginal soils. The effects of Yellow Cedar’s northward migration needs to be better understood to properly implement conservation strategies that can protect the longevity of the species. In particular, how does Yellow Cedar colonization alter soil conditions and forest ecosystem function? Soil biogeochemical analyses in pioneer stands indicate that the presence of Yellow Cedar improves the suitability of soils to many forest species; soils have higher N content and are less acidic. The results also illuminate a decrease in the bioavailability of soil carbon with the presence of Yellow Cedar, which suggests that the species increases carbon storage capacity of soils in temperate rainforests. This suggests an increase in soil respiration in areas of decline, a positive feedback cycle from global warming. Yellow Cedar is an important case study of the global impacts of climate change on our biosphere and a harbinger for many species as climate change intensifies.

  • Thumbnail for Water quality in Bali : a multiperspectival approach
    Water quality in Bali : a multiperspectival approach by Bellows, Zachary David

    Water pollution in Bali due to human waste and agricultural runoff is a serious concern. Social and cultural influences such as rigid social structures, tourism, and weak infrastructure contribute to water pollution on the island. In an attempt to quantify the extent of the pollution, nutrient concentrations and other relevant variables were measured at seven points along the Yeh Ho River seven times in June, 2013. Interviews were also conducted to provide social and cultural context. The results of the study indicate that nutrient concentrations increase significantly as the water travels downstream from 15 (± 1.9) to 40 (± 3.2) ppm nitrate-NO3 and from 0.16 (± 0.06) to 0.61 (± 0.06) ppm phosphorous-PO4. In addition, nutrient concentrations on June 18th were higher across all sampling sites than the measurements on other days by 9.0 (± 2.4) ppm nitrate-NO3 and by 0.53 (± 0.06) ppm phosphorous-PO4. Generally, the levels of N and P in the Yeh Ho River are significantly higher than the expected natural background levels of nutrients in rivers. These trends are likely attributable to significant, uncontrolled, anthropogenic inputs into the Yeh Ho River. The qualitative data corroborates this interpretation. Other explanations for this nutrient increase include changing uptake rate due to geomorphological changes of the river, or systemic error introduced by sampling downstream sites later. However, these factors are likely negligible relative to anthropogenic inputs.

  • Thumbnail for A Micrometeorological Study of an Abrupt Treeline on Pike’s Peak
    A Micrometeorological Study of an Abrupt Treeline on Pike’s Peak by Parish, Meredith

    Pike’s Peak Treeline Microclimatology: Our study site in Pike’s Peak is one of the few abrupt treelines that is advancing with recent regional warming. We established that there is most likely an eddy in the lee of timberline during askew flow as evidenced by the increasing size (both length and height) of a slow air bubble from parallel to askew flow. This increased size of the slowed air bubble creates sheltered conditions downwind of the shelterbelt. Shelterbelts are known to ameliorate agricultural health because eddies can create beneficial climatic conditions through decreased wind speeds. However, the eddy created in our study site may not create a better environment for tree growth. Tree establishment above 2H must be inhibited by too high of wind speeds creating high shear and near non-existent snow cover during the winter. The area between timberline and 2H has been slowly filling in with seedlings since the mid/late 1800’s. The trees in this section do not grow into krummholz form. If a seedling can be established it grows into a fully-grown symmetrical tree. It is difficult, but not impossible for seedlings to become established in this zone. Tree establishment is most likely dependent on very specific microsites within this area that have some wind flow, moderate snow cover in the winter, and 40-80% open sky exposure.

  • Thumbnail for The Cow in the Room: Regulating the Environmental Harms of Industrial Animal Agriculture
    The Cow in the Room: Regulating the Environmental Harms of Industrial Animal Agriculture by Palko, Gabriella

    Despite being the largest US methane emitter, the main source of water pollution, the driving force behind species extinction and habitat loss, and an intensive natural resource user, animal agriculture is scantily regulated and almost never considered as an option for combating climate change. This thesis seeks to provide a comprehensive analysis of the widespread environmental harms of the meat industry to demonstrate why it must be controlled. The historic 2015 Paris Agreement provides a framework for policy makers to address several ecological and climate threats, and regulating animal agriculture falls directly in line with the provisions put forth in the agreement. In order for the US to uphold their emissions reductions commitment and duties under the Paris agreement, industrial animal agriculture must be addressed. Current policies are examined as either hindrances or tools for controlling the detrimental impacts of the industry, followed by recommendations for policy vehicles and outlets to regulate the widespread degradation from industrial animal agriculture. If the earth is to avoid catastrophic climate change and ecological collapse, the cow in the room must be addressed.

  • Thumbnail for Unlocking an Abrupt Tree Line: A Synthesis of Micrometeorology and Vegetative Response
    Unlocking an Abrupt Tree Line: A Synthesis of Micrometeorology and Vegetative Response by Neumeyer, Eric Robert

    The advancement of global tree lines in response to climate change has raised questions among researchers about tree recruitment at elevations beyond tree line. This study aims to help understand this process by examining the progression of an abrupt tree line of engelmann spruce on the western slope of Pikes Peak, in Colorado Springs, Colorado. Methodology for this study includes drone photography, GIS mapping, dendrochronology, tree growth measurements, and soil moisture measurements. The results of our examination suggest that the three main mechanisms controlling advancement at our tree line include a leeward eddy when upslope winds interact with the tree line like a shelterbelt, a spiral eddy when winds are parallel to tree line, and cold air damming of katabatic winds against the tree line at night. Our examination of the vegetative response of trees at our tree line suggests that the most healthy recruitment is occurring on the southern edge of our transect and at the upper extent of the area expected to be protected by the tree line. We have found that trees and limbs that exist within the cold air dam at tree line have experienced decreased growth compared to trees outside of this layer of cold air.

  • Thumbnail for Projected distributional changes in Arctic-breeding passerines as a factor of land cover change in Northern Alaska
    Projected distributional changes in Arctic-breeding passerines as a factor of land cover change in Northern Alaska by Burk, Erin

    In North American bird species, breeding distributions are shifting north toward the poles with climate change (Hitch and Leberg 2007). Habitat type could act as a better predictor of shifts in the breeding distributions of territorial birds than elevation or temperature gradients alone, as both an individual’s breeding performance and adult survival depend on habitat suitability (Reif et al. 2010). Using models that predict how the vegetative structure will change in a tundra landscape, we can predict how territorial bird distributions might change alongside a warming climate as a factor of habitat type. This study makes population and bird species richness projections for tundra-breeding birds based on their habitat preference at the Primus Creek study site in the Noatak National Preserve, Alaska.

  • Thumbnail for Return to the Taoist Nature--RETURN TO THE TAOIST NATURE   Tracing the evolution of Nature Education in China for establishing a systematic experience-in-nature network
    Return to the Taoist Nature--RETURN TO THE TAOIST NATURE Tracing the evolution of Nature Education in China for establishing a systematic experience-in-nature network by Zheng, Aiyu

    People’s urgent needs for clean, safe, and enjoyable living conditions have enabled Nature Education (NE), a form of Environmental Education (EE), to burgeon to meet the needs of the environmental predicament in the People’s Republic of China (PRC). This emergent qualitative study was guided by grounded theory based on data collection and analysis from transcribing and translating 12 in-depth interviews with four case study NE organizations. Building on Integral theory and Maslow’s hierarchy of needs, this study analyzes how cultural perspectives of human-nature relationships contribute to the progression of indigenous environmental education. Based on three cycles of coding and the resulting themes that allowed me to trace the emergence and development of NE in PRC, this study presents a new model, the holarchy of human environmental needs, that includes needs on several levels: survival, resource utilization, social activities, psychological health, to self-actualization. When all levels of environmental needs are met through NE, participants can eventually attain the ultimate harmony with NATURE embodied in Taoism. Within the social context of increasing urban-rural differentiation in PRC, this study also proposes a systematic Experience in nature (EN) network, along with a list of practical suggestion for NE organizations and practitioners to take advantage of community networks, thus raising the efficiency of need-based environmental education.

  • Thumbnail for The Past and Future of Wildfire in the Colorado Springs Wildland-Urban Interface
  • Thumbnail for DCC Test thesis
  • Thumbnail for The Testimonial Experience of Civil Wars: A Question of Trauma Expression and Historical Representation
    The Testimonial Experience of Civil Wars: A Question of Trauma Expression and Historical Representation by Yamada, K'lah Rose

    The following paper will use the civil wars of Spain and Northern Ireland as two case studies for the analysis of the individual expression of trauma. I will establish the historical contexts of the two wars, followed by an examination and comparison of the collective and individual silences and the memorialization of the civil wars. Afterwards, I will analyze the effects of trauma on the individual expression of the civil wars. Finally I will discuss the limitations of the archives. Through the comparative study of two civil wars and the different methods of memorialization and representation, an argument may be made that in order to discuss an individual’s traumatic experience he or she may use the polyphonic discourse thereby allowing the speaker to both represent his or her experiences as well as begin to process any past trauma.


    A senior essay written on the changes of superheroes within america during the 20th century. Comparing the ways the characters have changed alongside the problems and successes of America. Captain America and Iron Man are the two main characters focused upon. The essay reflects on their differences in representing the positive and negative aspects of American Exceptionalism.

  • Thumbnail for From “Yellow Peril” to “Model Minority” in Popular Media: Continuity in Asian American Representation Before and After World War II
  • Thumbnail for The werewolf is afraid : translations of La sueñera by Ana María Shúa
  • Thumbnail for They Shall Take Up Serpents
    They Shall Take Up Serpents by Sarafan, Jamie Anne

    The American South has almost always been largely defined by its brand of fiery, passionate, evangelical Christianity. Within this, one of the most enduring images of Southern religion in the mind of the American public is the ritual of serpent handling. Featured in popular culture from Saturday Night Live skits to movies starring Will Ferrell, serpent handling has become almost synonymous with ideas and parodies of white, American Christian zealots. Further associated with poor, uneducated, white, “backwoods” members of Southern society, the power and meaning of serpent handling to believers is often overlooked in favor of sensationalized media accounts, which have led to unfair, unsympathetic national bias and stereotypes of a minority American religious group. What this thesis aims to do is, in part, begin to chip away at many of these stereotypes through exploring the cultural, social and theological origins of this uniquely Southern religious practice and help give serpent handling a legitimate place in the American religious history it deserves. What this thesis posits is that serpent handling emerged with the birth of the Pentecostal Church as a reaction to a white, Southern, masculine identity crisis that gripped the Post-Reconstruction South. More specifically, the genesis of this religious ritual was both highly temporal and regional in nature and emerged as a socially-reactive response to the cultural shifts brought on by the industrialization of the South, and originating at almost the exact the same time as other extreme movements in the area, such as the second generation of the Ku Klux Klan. By examining the practice through lens of masculine overcompensation thesis, a social theory which posits that when under both perceived and actual cultural threats, men reassert their manliness through bold, often dangerous, demonstrations of masculinity, what this thesis argues is that serpent handling emerged as a theologically and symbolically viable Christian fundamentalist means by which early Southern Pentecostals sought to reclaim their sense of manhood during a time of change.