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  • 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 Assessment of Phytoremediation in the Kerber Creek Watershed, Saguache County, CO
    Assessment of Phytoremediation in the Kerber Creek Watershed, Saguache County, CO by Berglund, Erika

    As a result of abandoned mining operations, the Kerber Creek Watershed in Saguache County, CO became the site of large-scale acid mine drainage and deposition. Consequently, highly acidic soils and subsequently toxic levels of bioavailable metals characterized the floodplain. In response to this environmental degradation, several groups including the USFS, BLM, ASARCO, Bonanza Stakeholders Group, and Trout Unlimited began remediating contaminated sites by adding neutralizing amendments, compost, and a seed mixture to the soils for the purpose of phytoremediation. This study aims to develop an understanding of the metal uptake and storage behaviors of the various plants that have established in the remediated sites. This information is intended to quantify the success of phytoremediation efforts and inform future work. Plant coverage was determined and samples of present species were taken at each site. Samples were then identified, cleaned, separated into different tissues, dried, powdered, digested with a nitric acid, microwave-assisted digestion procedure, and analyzed for metal content using an ICP-OES. All samples were found to have metal levels above that of critical concentrations for plants, suggesting that they are all highly metal tolerant. Translocation factors (metalaboveground:metalbelowground) were determined for each species and it was found that all herbaceous species sampled stored significant levels of metals in aboveground tissue, with TF factors above one and as high as eight, while grass species primarily retained metals in their roots, with TF factors for nearly all samples below one. Noticeable heavy grazing by cattle and the resultant presence of herbaceous weedy species seem to pose a threat to the long-term success of phytoremediation in the area. Future re-seeding efforts and the development of an improved cattle management strategy may be necessary to maintain a healthy, stable watershed.

  • Thumbnail for Causes and Consequences of Alpine Shrub Expansion on Pikes Peak, Colorado
    Causes and Consequences of Alpine Shrub Expansion on Pikes Peak, Colorado by Wheeler, Audrey Renee

    Alpine ecotones are often used as sites for measuring ecological responses to environmental changes. Recent decades of human-induced climate change have had a measured effect of increasing the altitude of alpine treelines in areas with increasing regional summer temperatures. On Pikes Peak (Southern Rocky Mountains, Colorado), there has been a measured treeline advance in the past several decades. The purpose of this study is to determine whether alpine willow shrubs on Pikes Peak are also advancing upslope in response to recent climate warming trends. After sampling ~300 shrubs in linear transects directed upslope, the shrubs were aged by counting and measuring annual growth rings. There is a significant negative correlation between shrub age and elevation for shrubs on the bottom of the valley (p=0.015). The mean shrub age decreases with increased elevation, and the ages in the lowest elevation band are significantly different from those in the highest elevation band for valley shrubs (p=0.041). The width of annual growth rings did not appear to have a correlation with annual or growing season temperature anomalies. A photographic analysis of aerial photographs from the past several decades was inconclusive. This study suggests that shrubs are increasingly recruiting at higher elevations on Pikes Peak, and have perhaps spread to their current elevation within the past 30 years. By surveying shrub movement in alpine environments, extrapolations can be made about how shrub distribution will change in the future and how shrubs may contribute to feedback cycles for regional climate phenomena.

  • 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 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.

  • 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 Effects of Wildfire on Biogeochemical Cycling in Ponderosa Pine Ecosystems
    Effects of Wildfire on Biogeochemical Cycling in Ponderosa Pine Ecosystems by Sherman, Ross Burchenal

    The frequency and severity of wildfires in the western United States is increasing, due primarily to a warming climate and unnaturally dense forests caused by policies of fire suppression. Ponderosa pine ecosystems, which historically have been subjected to mostly low severity ground fires, are now experiencing a drastically different fire regime. Carbon and nitrogen stocks, base cations, and strong acid anions were analyzed in response to wildfire severity in the Hayman and Waldo Canyon burn scars, located northeast of Colorado Springs, CO. Results show signs of persisting ecosystem disturbance twelve years after the Hayman Fire occurred, and two years after the Waldo Canyon Fire. Most notably, we observed depleted stocks of carbon and nitrogen in soil samples, as well as decreasing dissolved organic carbon (DOC) in response to percent of watershed disturbed. Base cations (K+, Na+, Mg2+, Ca2+) and sulfate (SO42-) were generally found to increase in response to percent burned at the less severe burn parameters, while nitrate showed a significant positive response to percent of watershed burned at high severity. These relationships suggest that ponderosa pine ecosystems are regenerating more slowly in response to this more severe fire regime, and questions remain about the forests’ ability to act as a reliable carbon sink.

  • Thumbnail for Electrified Reefs: Enhancing Growth in a Temperate Solitary Coral Species?
    Electrified Reefs: Enhancing Growth in a Temperate Solitary Coral Species? by Barnett, Rebekah Mae

    Coral reefs provide humans with important ecosystem services including food, pharmaceuticals, and water filtration (Moberg and Folke 1999). These ecosystem services, however, are at risk from ocean acidification, coral bleaching, and other destructive anthropogenic activities. Since these ecosystem services are costly to replace and their natural ability to restore themselves has been compromised, active restoration is necessary. A promising tool for active restoration is the Biorock® method. The Biorock® method consists of running an electrode through a large metal cathode and smaller anode. The electrical current causes the precipitation of calcium carbonate onto the cathode. The cathode works as an artificial reef framework by providing a natural substrate onto which corals can grow. Claims about the effectiveness of this technology in terms of increased coral growth, reproduction, health, and diversity are spectacular (Goreau and Hilbertz 2005), but independent research is divided on the question of its effectiveness. In an attempt to help clarify the technology’s effectiveness, we conducted laboratory experiments to test the claims of growth enhancement for the electrolytic technology by exposing the temperate solitary coral Balanophyllia elegans to powered and unpowered treatments. The study focused on coral growth, but careful observations were made on other aspects of the community including presence and thickness of algal cover. Our results are not consistent with claims made about the benefits of electrolysis on coral growth. Growth between treatments was significantly different but, while claims suggest a 3 to 5-fold increase in growth (Goreau 2014), corals exposed to an electrical current grew less than control corals. The results suggest that the electric current may actually depress growth. A species-specific tolerance to electrical currents may help explain our results as well as the variation seen in other studies. In addition to variation caused by species tolerance and current level, there also seem to be overall trends of the technology being effective for warm-water corals, but ineffective or even detrimental to cold-water corals. The variation in effectiveness between warm and cold-water species is surprising given the proposed physiological mechanisms behind the benefit and suggests that photosynthesis may play an important role in determining whether or not the technology is effective. Our results suggest an ability of the electrical current to depress the growth of algae, which can positively impact photosynthesis and the corals’ ability to calcify. Algae inhibition can therefore play an important role in determining whether or not the technology is effective, but is still part of a complex interplay between current density, ion availability, algae and photosynthesis. Further study is needed to clarify these interactions and their role in determining the effectiveness of the Biorock® method.

  • Thumbnail for Federal regulation of hydraulic fracturing: Fusing the fissure between energy and the environment
    Federal regulation of hydraulic fracturing: Fusing the fissure between energy and the environment by Lavietes, Rebecca

    This thesis advocates for the federal regulation of hydraulic fracturing based on two fundamental arguments. First, I argue that natural gas will be the primary energy source in the United States over the next few decades focusing on the national security implications associated with climate change and foreign oil dependencies. Second, I argue that federal regulation is the only way to ensure the continued development of domestic natural gas due to growing public concern pertaining to groundwater contamination. Finally, the paper presents four policy recommendations to be carried out on the federal level.

  • Thumbnail for Global Climate Change and National Park Service Management
    Global Climate Change and National Park Service Management by Moss, Kevin Nicholas

    The National Park Service (NPS) manages over 84 million acres of public lands in the United States. Its landscapes include some of the most visually stunning and ecologically pristine areas of the country. The parks, monuments, wildernesses, and protected areas that encompass the NPS are largely protected from human development, but that does not mean they are immune from disturbance or damage. In the past, impacts to these landscapes were largely due to poor land use decisions, such as overgrazing by cattle and fire suppression. However, a new threat – global climate change – threatens to significantly disturb these pristine areas. The NPS faces a substantial challenge in formulating effective management strategies to mitigate the impacts of climate change. This thesis investigates the system-wide response by the NPS to climate change in two ways. First, a comprehensive review of environmental management strategies was explored, with a focus on responses that could be particularly effective in a directionally changing climate. Second, a series of interviews with NPS managers and scientific researchers was conducted in order to contextualize the unique challenges that individual parks face regarding climate change. Interview responses were then discussed alongside the literature findings in order to explore the NPS’ response to climate change. The thesis concludes with specific recommendations for how the NPS can improve its strategies to mitigate the impacts of climate change on its landscapes.


    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.  


    Thermal conditions control the elevation to which trees persist in alpine settings. Long-term historical data suggests a correlation between periods of anomalously warm regional temperatures and treeline advance on Pike’s Peak (Southern Rocky Mountains, Colorado, USA) (Kummel et al., W.I.P). Still, treelines do not uniformly respond to warming and treeline form is shown to be an indicator of sensitivity to warming (Harsch & Bader, 2011). This dependence suggests that further investigation of the relationship between climate and treeline movement is warranted. While alpine vegetation are controlled by the climate at treeline, they also interact with the air around them and in this way influence local climate. This report focuses on the microclimatology of air parcels surrounding individual trees and the relationship between microclimatology and tree growth. We found important results that indicate the formation of distinct microclimatological regions around individual trees. Specifically, it seems that trees act as a barrier to upslope airflow and in so doing cause the formation of eddies on the leeward side of trees. The longer residence times of entrained air tends to correspond with elevated temperature and moisture conditions. This microclimate formation suggests that trees process and shape their local climate in interesting ways. Understanding the sensitivity of treeline to climate change will be a question of understanding the interaction of local tree climate with that of the overall treeline.

  • Thumbnail for Major and trace element geochemistry of pedogenic carbonates as a proxy for climate change during the ETM2 and H2 hyperthermal events in the Bighorn Basin, WY
    Major and trace element geochemistry of pedogenic carbonates as a proxy for climate change during the ETM2 and H2 hyperthermal events in the Bighorn Basin, WY by Hopper, Elizabeth Ann

    A series of rapid global warming events, triggered by the release of CO2, occurred at ~55.5 Ma. These events are called hyperthermals, and they have garnered a great deal of attention as probable analogs for present-day CO2 increase and climate change. The best known hyperthermal event is the PETM, which was followed by two smaller events called ETM2 and H2. Pedogenic carbonate nodules from the Bighorn Basin in Wyoming provide the first terrestrial records of ETM2 and H2. Since pedogenic carbonates precipitate out of the groundwater, the major and trace element composition of these nodules can be used as a proxy for groundwater conditions during ETM2 and H2. The ratios Na/K, Na/Al, K/Al and Mg/Al were used as weathering indicators. Boron was used as a proxy for pH, and Phosphorus was used as a proxy for plant activity. The redox sensitive elements Fe, Cu, Se, V, U Zn, and Ni were considered as proxies for soil saturation. Comparison of pre hyperthermal to mid hyperthermal groundwater chemistry indicates that (1) Weathering intensity and sedimentation rates decreased during ETM2 and H2 (2) soil and groundwater became more acidic during ETM2 and H2 (3) The acidification was primarily driven by increases in plant activity during ETM2 and (4) Average rainfall decreased during ETM2, but the hyperthermal was characterized by wet and dry cycles.

  • Thumbnail for Micrometeorology of a Diffuse Tree Line: How do airflow structures affect sensible heat flux divergence and temperature-controlled tree growth?
    Micrometeorology of a Diffuse Tree Line: How do airflow structures affect sensible heat flux divergence and temperature-controlled tree growth? by Sondermann, Dylan P

    Harsch (2009, 2011) determined that diffuse tree lines are advancing globally as a response to warmer growing season temperatures. However, few have studied the local micrometeorological processes that change local climatic conditions for trees. This thesis aims to understand local airflow patterns and heat distribution within a diffuse tree line on Pikes Peak (Teller County, CO). Previous research identified that the study site represents an advancing tree line that has transitioned from an abrupt to a diffuse structure within the last century (Kummel et al. 2009-present). The mountain location of the study site governs large-scale wind patterns as an anabatic-katabatic wind system. On a more local scale, surface interactions at the diffuse tree line alter daytime flows, resulting in the formation of a low level jet. This jet alters climatic conditions by creating three vertical sub-layers with different atmospheric properties. A preliminary heat budget analysis of the diffuse tree line confirms the findings of jet characteristics while also determining that the low level jet is capable of altering vertical heat distribution and depositing heat as flows move uphill. This heat deposition is likely connected to growth patterns studied by Marks (2014) and overall tree line dynamics (Elwood et al. 2012).

  • Thumbnail for Rethinking "Wild" and Shifting the Management Paradigm: Facilitating 21st Century Conservation through the BLM's Wild Horse Program
  • Thumbnail for The Vulnerability of California Amphibian Species to Climate Change
    The Vulnerability of California Amphibian Species to Climate Change by Ben-Zeev, Rayna

    Amphibians are declining on a global scale, faster than any other taxonomic group. Although I am still unsure of the causes of many local declines, I have evidence that on a larger scale temperature and precipitation changes caused by climate change directly relate to broader amphibian disappearances. I aim to use past temperature and precipitation trends and amphibian distributions in California to predict future amphibian distributions. I use the Biomod2 package in R, along with CMIP5 climate layers and emissions scenarios to correlate amphibian distributions to climate, and predict a range of future possibilities for amphibians under different carbon emission scenarios. I hope to identify which species are most in danger of extirpation to hopefully direct future management initiatives to these species.