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.
Abstract Neonicotinoids are a unique class of insecticide used extensively in the agricultural industry. They were first introduced to the agrochemical industry in the early 1990’s. Since then, neonicotinoid use has grown almost exponentially due to their favorable qualities. The insecticide is effective because it acts as a neurotoxin that targets insect neuronal nicotinic acetylcholine receptors, which allows the chemical to be selectively lethal to insects. Scientists, farmers, and beekeepers have recently become concerned about pollinator exposure to neonicotinoids due to dramatic declines bee populations. Pollinators can be exposed to neonicotinoids through a variety of different pathways, including consumption of contaminated pollen and nectar. Scientific research suggests that neonicotinoid exposure can have both lethal and sublethal effects on pollinators. Pollinators provide a very important ecosystem service, yet they are constantly subject to risk through neonicotinoid exposure. This study examines the role of the Environmental Protection Agency in regulating potentially harmful pesticides and concludes with suggestions for amending the Federal Insecticide Rodenticide and Fungicide Act as well as for regulating neonicotinoids.
Pattern formation in ecosystems via self-organization is an important area of investigation in the field of ecology. Self-organization is the process whereby short-range facilitation and long-range inhibition lead to patterns in ecosystems at varying scales. Can biotic agents, such as key ecosystem engineers, be responsible for patterns of self-organization? We sought to investigate this question on the tundra of Pikes Peak outside Colorado Springs, CO. Aerial images of Pikes Peak reveal distinct patches of alpine avens (Geum rossii) dotting the tundra. Are there any patterns in the distribution and characteristics of these alpine avens patches? Closer examination reveals that evidence of northern pocket gopher (Thomomys talpoides) soil disturbance also speckles the tundra. Are there any links between gopher disturbance and alpine avens patches? We sought to answer these broad questions through a series of three investigations. We examined the large-scale spatial distribution of the avens patches relative to each other, surface gopher disturbance in relation to individual avens patches, and the underground characteristics of the tundra below the patches. Our findings indicate that while a link can be established between gopher disturbance and avens patches, it is not the complete picture. We found that contrary to the expectation that avens patches would follow a regular distribution at smaller distances, they were in fact randomly distributed at small distances and clumped at greater distances as shown by Ripley’s K tests. In line with our hypotheses, we found that gopher disturbance was clumped, and occurred more often within avens patches than would be expected given disturbance frequency across the tundra, p=0.001 (chi-squared=10.88, DF=1) for quadrant one, and p=0.0001 (chi-squared=306.96, DF=1) for quadrant two. Finally, we discovered an interesting pattern of what appears to be disintegrated bedrock beneath the avens patches, which may have implications for avens patch resilience on the tundra. In t-tests comparing mean resistivity of soil underground inside and outside the patch, p<0.05 for all depths except the lowest depth in one patch. In sum, it appears from our findings that while gopher disturbance may be necessary for avens patches on the Pikes Peak tundra, it is not sufficient. This is given the fact that gopher disturbance occurs in areas where avens patches do not, and avens patch boundaries are crisply defined while gopher disturbance is diffuse. Evidence does seem to point to self-organization on the tundra, with gopher disturbance creating short-range facilitation for alpine avens, and some mechanism of long-range inhibition preventing avens patches from occurring everywhere on the tundra.
The awareness of sustainability issues has increased the demand for contemporary environmental, social, and economic solutions. The green building movement, with LEED as the primary assessment standard in the United States, is a major focus of urban sustainability and the built environment. The Catamount Center Dorm, an ~3,000 sq. ft. small environmental education dorm at the rural Catamount Mountain Campus, located in Woodland Park, Colorado, underwent a preliminary LEED evaluation during the early construction stage. This qualitative case study identifies three theoretical constructs that address contestable concepts and gaps within the literature, and may be beneficial for directing future study; they include 1) LEED can serve as an effective educational tool for students, building designers, and LEED accredited professionals 2) LEED impacts building design team dynamics, influencing individual roles, advocacy, and group conversations, 3) LEED provides narrow sustainability solutions within the greater scope of green building practices and should be weighted against the larger ambitions of a project.
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.
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.
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.
This thesis seeks to determine the most effective means of distributing appropriate sustainable energy technology to individuals that have no access to energy services. There are approximately 1.4 billion people around the world that are ‘energy-impoverished.’ ASETs are small-scale clean energy technologies that fill the immediate energy needs of these individuals. There are, however, seven fundamental barriers limiting the dissemination of these technologies. These barriers result from the microeconomic and sociological conditions of these populations. This thesis analyzes 12 unique distribution models from companies, nonprofit organizations, and universities, and shows how each model performs relative to these barriers. Following this analysis, I propose the most effective means of distribution ASET to energy-impoverished populations. Title on PDF: Methods for distributing appropriate sustainable energy technologies in developing nations : a comparative analysis
Warmer and drier conditions as a result of climate change are expected to have significant effects on closed cone conifer ecosystems, including changes in disturbance regimes, reduced plant growth, and decreased seedling recruitment. Changes in the fire regime could potentially cause localized extinction by narrowing the fire interval past the point compatible with the reproductive timeframe of the closed cone forest. The “interval squeeze hypothesis” describes the synergistic effects of changes in disturbance regimes, plant growth, and seedling recruitment, and suggests that closed cone conifer ecosystems may face extinction sooner than initially accounted for. California closed cone pine species provide a unique way to test the interval squeeze hypothesis. Their short lifespan and fire return interval allow data to be collected over the lifetime of the forest and quantify changes caused by climate change. Stand structure and composition metrics were measured at six sites in California and Colorado. The univariate comparison of metrics showed that California and Colorado pine species are similar across important aspects of stand structure and composition. As such, there is potential for California forests to serve as a model ecosystem for Colorado forests. Pinus contorta var latifolia (Lodgepole Pine) is one of the most widespread tree species across western North America. A large-scale mortality event of P. contort var latifolia forest could cause significant change to the carbon sequestration and water infiltration capacity of these forests.
Atmospheric mercury (Hg), an airborne heavy metal, can be deposited into aquatic and terrestrial systems, posing a risk to ecosystems and human health. It is therefore important to understand the sources, chemical cycling, and fate of atmospheric mercury. This study looks at total gaseous Hg (TGM) and total Hg (THg) concentrations collected at an urban near-road site in Colorado Springs, CO from June - August, 2016 and at a rural location in Rocky Flats National Wildlife Refuge, Louisville, CO, from June - August, 2018. Mercury concentrations at the two sites were significantly different from one another. The urban data set reveals a significant diurnal pattern, with hourly average TGM concentrations reaching a maximum at 3:00 MST (1.9 ± 0.3 ng/m3) and minimum at 13:00 MST (1.6 ± 0.2 ng/m3). In contrast, at the rural site we find that hourly-average concentrations peak at 13:00 MST (1.5 ± 0.1 ng/m3) and are lowest at 6:00 MST (1.4 ± 0.1 ng/m3). These diurnal Hg patterns are comparable to those found in other studies looking at urban/rural differences. Sources of Hg at both sites were also investigated. At the urban site, the data points to high TGM concentrations originating from local sources. Additionally, strong correlation between TGM and CO2 suggests soil evasion as a potential Hg source. The rural site, on the other hand, does not appear to be influenced by nearby Hg point sources and reflects a typical background site.
Management of the Columbia River has come to an impasse: after decades of litigation and controversy, there is a growing sense among stakeholders that there may be no good solution to the conflict between endangered salmon and the region’s expansive hydroelectric generation system. Dams and reservoirs pose severe challenges to the survival and migration of salmon and have been blamed for significant population declines over the past century. Addressing this issue, however, is complicated by the fact that river management strategies to benefit the fish often require operational changes that reduce the productivity of hydroelectric power generators, and thus they are strongly opposed by hydroelectric interests and dam operators. Still, the National Marine Fisheries Service, the agency charged with ensuring that other federal agencies’ actions (including actions of federal dam operators) do not jeopardize listed species, is constantly pressured by Native American tribes, environmental groups, and other stakeholders to implement just that sort of management plan. Caught between the two sides, the NMFS, instead of being decisive, has tended to avoid upsetting the status quo and has been often criticized for it. This report seeks to explain why the NMFS has been so reluctant to regulate the hydroelectric system. It shows that, despite the authority of the NMFS the Endangered Species Act, they must operate within the confines of what is politically feasible. Political feasibility is constrained in part by the legacy of a trend toward neoliberalism that gained influence in U.S. politics during the 1980s and 1990s. Specifically, neoliberal policies aimed at limiting federal involvement in economic activities and private land under the ESA have become impediments to federal action in the Columbia that would give endangered fish priority over development activities that threaten their survival. Two such policies are analyzed in this report, the “no surprises” policy, which was originally designed for private landowners but is now used between regulating and regulated agencies, and the “best available science” mandate for federal action under the ESA.
Invasive species are becoming increasingly problematic as human activities and climate change accelerate their spread to new areas. The invasive grass Bothriochloa ischaemum (King ranch bluestem) has taken over large portions of the savanna on the Edwards Plateau in central Texas. Given its pervasiveness, it greatly reduces the populations of native grasses and forbs, and land managers are looking for effective ways to control this species. Recurring fire is necessary to maintain savanna ecosystems; this study aims to determine the most effective timing of fire for controlling B. ischaemum and maintaining a diverse savanna ecosystem. An unreplicated randomized block design was used, in which plots were burned at different times of year during 2016, or left unburned as a control. Pre-fire moisture data, soil temperature data from the duration of the burn, and post-fire plant species data were taken from each plot. These data show that there is a non-significant correlation between August burns and higher fire intensity, and a slight negative correlation between fuel moisture content and higher fire intensity. There was a nonsignificant trend towards lower species richness in unburned plots. On average, a plot burned in August or October was less likely to have B. ishcaemum than a plot burned in February or April, or left unburned. Prescribed burns successfully increased the abundance of native perennials, especially when done in the late summer. These results are probably due to differences in plant phenology at the time of each fire. Native plants are adapted to summer fires, while B. ischaemum could be at a vulnerable phenological stage during the summer. These findings have important implications for the management and restoration of central Texas grasslands. We recommend that land managers use prescribed burns during late summer in order to control B. ischaemum and boost ecosystem health.
Treelines are climatically constrained ecotones existing worldwide. With global warming and climate change, treelines are expected to advance in elevation on a global scale. Previous research has shown that abrupt treeline shapes are advancing at far slower rates than diffuse treeline structures, indicating that temperature increases are not the only factor. Smaller-scale, endogenous factors may be at play including microclimates, tree-to-tree interactions and feedbacks. Our study at an abrupt treeline on Pike’s Peak aims to understand the effects of temperature and smaller-scale factors on seedling growth, in the effort to try and understand the feedbacks involved in treeline movement and formation. Results indicate that this specific abrupt treeline is creating a microclimate that facilitates seedling growth above the historical treeline. Once this new growth of seedlings matures, another abrupt treeline will form and perpetuate the process.
The combination of environmental and spiritual threats posed by mining on sacred geographies is exemplified in the struggle for Chi’chil Bildagoteel , or Oak Flat, a site in southeastern Arizona sacred to the San Carlos Apache Tribe that is currently threatened by an impending copper mine.
In this thesis, I conduct a transnational analysis of the racialized hierarchies I observed during my research at La Clínica, a midwifery school and birth center on the U.S.-Mexico border. The discourse surrounding La Clínica couches the border space and the clinic in benevolent terms, but interviews with students of color reveal complicated racial and class politics that mediate the clinic and their experiences learning and working there. Students of color are thus motivated to form and create varying modalities of agency in order to define their experiences on their own terms, to express gratitude, and as a vehicle for survival in a predominantly white institution.
Using The Guide to Getting It On and The Joy of Sex, this paper explores the ways in which sex guides address queer identities. The arguments presented rely on queer theory, particularly the work of Annamarie Jagose and Eve Sedgewick, to understand queer as an unstable and dynamic category of identity. The paper then turns to The Guide to Getting It On and The Joy of Sex to examine how sex guides uphold hegemonic standards of heterosexuality and whiteness and further marginalize queer identities and people of color, arguing that sex guides cannot account for queer identities and are inherently exclusionary even when they aim to be inclusive.
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.
The rise of the consumer economy in the United States during the 20th century brought about the rise of advertising. Advertising became such an integral part of our luxury economy that different methods and techniques had to be developed in order to attract a consumer base on a psychological level. Due to a multitude of factors, however, the popularity of psychological advertising did not increase as quickly as other scholars in the field might believe.
Visitors to North Africa have long noticed a sharp contrast between the lush landscape described in ancient texts which supported Roman cities like Leptis Magna, and the more arid, barren landscape of North Africa today. Environmental historians have traditionally attributed this contrast to a decline in the extent of forests and in agricultural fertility since the start of the Roman period, brought on by an overexploitation of Rome’s natural resources. Recently, however, this model has been criticized by several post-colonial and environmental theorists, who argue that the idea of decline in North Africa is a colonial invention that allowed Europeans to exert control over North Africa’s Arab and Berber populations. This essay seeks to evaluate the history and the historiography of the North African environment, and of the Mediterranean environment more generally, to uncover the extent to which decline may have occurred. It concludes that environmental decline did indeed occur in North Africa, but the source of this decline was the Roman Empire itself. The nomadic Arab people of North Africa cannot be blamed for the environmental changes which took place before their arrival. At the same time, human-influenced decline must not be ignored when considering the Roman Empire’s complex legacy.
This thesis paper will attempt to analyze the interaction of Chinese and Western medicines throughout the end of the nineteenth and early twentieth centuries. In particular, pain management will be used as a framework for understanding these interactions, especially in light of how anesthesia and post-operative pain relief methods were developed separately and then in tandem with these bodies of medicine. How can the evolution of Chinese medicine as it came in contact with Western medicine in the twentieth century help us to understand the culmination of medicine interactions such as acupuncture anesthesia in the 1970’s? In looking at the late nineteenth century (both in the West and in China), the Republican period in China, the Communist Revolution of 1949 in China, and the significant decade of US-China rapprochement in the 1970’s, an investigation of pain management and how Chinese medicine and Western medicine interacted is conducted. Chinese medicine has been favorably adaptive in relation to its traditional history and how it amalgamated with Western science, and there are aspects of Chinese medicine that should be incorporated into Western medical systems today.
This thesis explores the question of how Orange County and Los Angeles counties formed distinct identities in the years after World War II ended. This thesis will claim that historical events in the postwar years created unique communities in the two counties that allowed Orange County to develop its own identity, separate from the assumption that it is a suburb of Los Angeles. The creation and opening of Disneyland in Anaheim, California in 1955 marks a pivotal turning point for the forming of identity in Orange County. Additionally, the growing conservative movement in Orange County is necessarily different from the climate in urban Los Angeles. The movement in support of republican candidate Barry Goldwater in Orange County in 1964, specifically contrasted with the presence of a race riot in Los Angeles in 1965 concretely distinguishes the identities of the two counties. The event of the Riot simply could not have occurred in the homogenous community in suburban Orange County by 1965, solidifying the unique identity of Orange County.