Mountain Scholar :: Browsing by Author "Leisz, Stephen, committee member"

Browsing by Author "Leisz, Stephen, committee member"

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Open Access
Africa's fuelwood footprint and the biome-level impacts of tree harvest
(Colorado State University. Libraries, 2014) Tredennick, Andrew T., author; Galvin, Kathleen, advisor; Hanan, Niall P., advisor; Coughenour, Michael, committee member; Leisz, Stephen, committee member
To view the abstract, please see the full text of the document.
Open Access
Analysis of land use change and greenhouse gas emissions in Kalasin Province, Thailand
(Colorado State University. Libraries, 2018) Chailangka, Preeyarat, author; Paustian, Keith, advisor; Fonte, Steven, committee member; Leisz, Stephen, committee member
Growing global population causes many stresses on the environment, perhaps the most serious is global warming due to Greenhouse Gas (GHG) emissions. Major contributors to GHG emissions include agricultural production and land use change. Southeast Asia is one of the world's fastest growing regions and provides many crops for export, so the land use changes are rapid and not always made in an environmentally conscious manner. The province chosen for this study, Kalasin, is located in a major economic development region with the multi-country East-West Economic Corridor (EWEC) running through it. The EWEC has brought many changes to this province such as expansion of the manufacturing sector, more urban growth to support new factories, and new roads to reach areas which were previously not developed. The largest single land use in Thailand and the Kalasin province is cropland. There have been many changes in farming practices in the province as well, from the types of crops grown to the increasing numbers of commercial farms. These shifts in land use are leading to changes in the amount of GHG emissions and are also leading to land degradation in parts of the province as well. The largest GHGs emissions in agricultural sector come from rice cultivation (45%), followed by biomass carbon stock losses (40%). Some government policies have led to crops being grown on unsuitable lands, which is often associated with greater use of fertilizers and intensive tillage practices applied. Other practices involve draining wetlands, creating rice paddies on unsuitable soils, or clearing forests to farm the area. In this study we look at land use and land use changes throughout the province and use that data to estimate a GHG emissions inventory in the agricultural sector in order to better understand the effects that growth, land use and land use changes in the Kalasin province have on the environment.
Open Access
Assessment and improvement of hydraulic disinfection efficiency of a live small drinking water system in South Africa
(Colorado State University. Libraries, 2018) Baker, Jessica L., author; Venayagamoorthy, S. Karan, advisor; Niemann, Jeffrey, committee member; Leisz, Stephen, committee member
Since the implementation of chlorination, the most common method of water disinfection, diseases such as Cholera, Typhoid Fever, and Dysentery have been essentially eliminated in the U.S. and other industrialized countries (WHO 2017). However, these nations still experience challenges in meeting drinking water standards. In 2009, the Colorado Department of Public Health and Environment contracted Colorado State University (CSU)'s Department of Civil and Environmental Engineering to address the poor hydraulic disinfection efficiency of contact tanks of small-scale drinking water systems. From this research, the Baffling Factor Guidance Manual (2014) was published, which presents innovative modifications proven to increase the hydraulic disinfection efficiency of small-scale contact tanks. The proposed innovative technology has the potential to have a significant positive impact in developing nations since at least 2 billion people worldwide use a drinking water source that is contaminated with feces (WHO 2017). Historical experience suggests that simply transporting a technology does not necessarily equate to long-lasting impact, but how that technology is transferred is critical to its sustainability. A successful solution to the need for disinfected water must be holistic, taking into consideration culture, law, politics, economics, environment, etc. The focus of this thesis is to investigate further the application of the innovative contact tank modifications of an inlet manifold and random packing material (RPM) on live systems. A case study was conducted on a small waterworks in the rural town of Rosetta, KwaZulu-Natal, South Africa, in collaboration with Umgeni Water. Physical tracer tests were conducted on a 10,000L cylindrical tank acting as the contact chamber to assess the hydraulic disinfection efficiency in terms of baffling factor (BF), before and after the installation of a 4-way inlet manifold modification. This modification resulted in a 37% improvement in the BF, increasing the contact time (CT), an important aspect of disinfection, in the cylindrical contact tank from 8.4 min-mg/L to 11.0 min-mg/L. In addition to the international case study, a pilot study was conducted at CSU to address the biofilm formation concerns of the innovative use of random packing material (RPM) in contact tanks. Preliminary results support the hypothesis that the presence of a disinfectant in the contact tank, though in the process of disinfecting the water, would mitigate the growth of a biofilm on the RPM.
Open Access
Building on sustainable development goal indicator 11.3.1. for improved utility and guidance
(Colorado State University. Libraries, 2023) Cardenas-Ritzert, Orion, author; Vogeler, Jody, advisor; McHale, Melissa, committee member; Leisz, Stephen, committee member
The increased production of broad-coverage spatial datasets and investigation of these datasets by spatial analysis techniques allows for consistent examinations of urbanization patterns across the globe. Spatial data and analyses have proven valuable for sustainable urban development initiatives, including Sustainable Development Goal (SDG) 11 under the United Nation's 2030 Agenda for Sustainable Development. SDG Indicator 11.3.1 is a geospatially measured indicator implemented under SDG 11 for monitoring rates of urban expansion and population growth in a specific area over a period of time. Current methodological approaches and data inputs may hinder the application of SDG Indicator 11.3.1 at certain scales and extents. The overarching goal of this research is to build on the utility of SDG Indicator 11.3.1 by enhancing an existing urban delineation method for automated function, examining urban change at the urban agglomeration level across broad extents, highlighting hotspots of SDG Indicator 11.3.1, and evaluating the impacts of the spatial resolution of data inputs on SDG Indicator 11.3.1 and related outputs. In Chapter 1, we advanced an existing urban delineation method for the automatic identification of individual urban agglomerations across broad extents. We accomplished this by integrating various open-source datasets and tools with spatial analysis techniques. We used this methodology to examine SDG Indicator 11.3.1 and additional urban change metrics for urban agglomerations in Ethiopia, Nigeria, and South Africa over the 2016 to 2020 period. In Chapter 2, we applied our delineation methodology and examined the influence of spatial resolution of land use data on urban delineation, urban change metrics, and urban related land use change in Ethiopia over the 2016 to 2020 period. The results of Chapter 1 revealed trends of urban change and highlighted hotspots of SDG Indicator 11.3.1 at multiple levels across the three African countries. Chapter 2 revealed the implications of using varied spatial resolutions of land use maps when delineating urban areas, assessing SDG Indicator 11.3.1 and other urban change metrics, and examining urbanization-driven land use change.
Open Access
Cuexcomate or temezcal?: deciphering the circular architectural features at Angamuco, Michoacán, Mexico
(Colorado State University. Libraries, 2013) Ahrens, Corrie, author; Fisher, Christopher T., advisor; Leisz, Stephen, committee member; Didier, John, committee member
The Middle Postclassic Purépecha site of Angamuco in the Lake Pátzcuaro Basin, Michoacán, Mexico possesses a significant number of circular architectural features. Comparison of these features to similar structures across Mesoamerica suggests their function as cuexcomates (granaries) or temezcals (sweatbaths). Based on comparative research of storage structures and sweatbaths employed throughout Mesoamerica, identification of physical attributes associated with cuexcomates and temezcals provided a basic foundation for identification of these structures during field survey. The availability of GPS and LiDAR data enable the use of spatial spatial statistics resulting in the identification of statistically significant spatial clustering of the circular features based on diameter. These clusters reside in elite and commoner residential and public/civic-ceremonial areas. Further inspection of these areas has provided insights into storage behavior, socio-economic characteristics, access, and urban development among the Purépecha. Future research at Angamuco providing the existence of additional circular features will aid in better identification of circular structure types and the expansion of storage knowledge and spatial analysis techniques employed at archaeological sites.
Open Access
"Destination Pine Ridge": a longitudinal case study of barriers to collaboration in culturally appropriate tourism initiatives
(Colorado State University. Libraries, 2013) Akers, Andrea, author; Pickering, Kathleen, advisor; Leisz, Stephen, committee member; Cottrell, Stuart, committee member
According to Ross et al. (2011) there are many barriers to genuine collaboration and natural resource co-management between Indigenous groups and westernized government groups but do these barriers exist for partnerships with Indigenous groups in other realms? This thesis is a specific case study of a partnership between the Pine Ridge Area Chamber of Commerce, the National Park Service, and several other South Dakota entities involved with the region's tourism industry. This partnership, as a strategy to increase tourism to the Pine Ridge Indian Reservation in South Dakota through education, has had to tackle many of the same barriers as Ross et al. (2011) argues exist for natural resource co-management attempts, but have also made significant achievements. A participatory epistemology and Pierre Bourdieu's (2009[1977], 1991, 1986) concept of capitals elaborate the case study analysis. This partnership has a long way to go before it is truly and equally collaborative, and has to confront many barriers until Lakota knowledge is incorporated into NPS interpretation. It has, though, accomplished many important steps to facilitating a mutually beneficial partnership have been accomplished, as well as individual growth and understanding among the participants.
Open Access
"Die at home": a contextualization and mapping of the New York City Draft Riots of 1863
(Colorado State University. Libraries, 2018) Hoehne, Patrick Tyler, author; Gudmestad, Robert, advisor; Leisz, Stephen, committee member; Payne, Sarah, committee member
This thesis attempts to contextualize and explore the New York City Draft Riots of 1863 – one of the deadliest instances of civil insurrection in American history – in order to prove that the violence of the riots was neither completely undirected nor uniform. At the heart of this argument is the simple idea that violence is never random. The first two chapters contextualize the Draft Riots within the greater experience of New York's Irish population, both in the Civil War and at home in New York City. The final two chapters, through a spatiotemporal analysis, seek to isolate patterns within riot violence in order to better understand the differing targets and tactics of rioters throughout the unrest.
Open Access
Floodplain organic carbon storage in the central Yukon River Basin, interior Alaska
(Colorado State University. Libraries, 2018) Lininger, Katherine Blom, author; Wohl, Ellen, advisor; Covino, Tim, committee member; Leisz, Stephen, committee member; Rathburn, Sara, committee member
River channels and floodplains transport, transform, deposit, and store organic carbon (OC) as active participants in the carbon cycle. Two of the largest stocks of OC in floodplains include soil and downed large wood (LW). This dissertation investigates floodplain OC stocks in LW and soil, and the geomorphic controls on soil OC stocks in the central Yukon River Basin in the Yukon Flats region of interior Alaska. The Yukon Flats region contains discontinuous permafrost, has a semiarid boreal climate, and has experienced little human modification. Almost all studies of floodplain OC have occurred in the temperate regions, despite permafrost regions storing large amounts of OC in the subsurface due to cold and wet conditions. In addition, relatively little is known about the geomorphic processes that control soil OC distribution on the landscape, particularly over large regions. Wood has been removed for navigation and infrastructure protection in many river corridors, and thus knowledge of natural wood loads, particularly on floodplains, is limited. I first present floodplain downed large wood measurements for the Yukon Flats region, and compare those measurements to downed wood loads in unaltered floodplains in two additional biomes, the subtropical lowlands and the semiarid temperate mountains. Average volumes of downed LW are 42 m3ha-1, 50 m3ha-1, and 116 m3ha-1 in the semiarid boreal, subtropical, and semiarid temperate sites, respectively. I find patterns in LW loads reflect climatic controls, such as decay rate and primary productivity, as well as increases in floodplain downed wood loads with recent disturbances such as fire. Next, I assess the geomorphic controls on floodplain soil OC concentrations along the Yukon River and four of its tributaries using a large dataset of floodplain soil samples, finding that river basin characteristics and geomorphic unit characteristics likely influence the spatial distribution of soil OC on the landscape. Average OC concentration within floodplain soil is 2.8% (median = 2.2%). Most floodplain soil OC likely comes from riparian vegetation, which is influenced by channel migration rates and the development of geomorphic units within the floodplain. Greater variability in OC concentrations among geomorphic units compared to among river basins indicates that a bottom-up approach to estimating OC on the landscape (scaling up from small-scale landscape units) may be necessary. Finally, I estimate the soil OC stock in the floodplains of the Yukon Flats and find that my estimate results in approximately an 80% increase in OC stock when compared to a previously published database. The residence time of floodplain sediment is constrained using radiocarbon dates taken from cutbanks, and indicates that OC may be stored in floodplains for over 7000 years before being eroded by the channel. This dissertation provides much needed information on the geomorphic controls on floodplain OC storage in permafrost regions, which are undergoing relatively rapid warming due to anthropogenic climate change. In addition, it highlights the importance of accounting for floodplains as unique landscape units and mediators of OC fluxes, water, and nutrients.
Open Access
Frontier beer: a spatial analysis of Denver breweries, 1859-1876
(Colorado State University. Libraries, 2019) Neihart, Braden, author; Orsi, Jared, advisor; Archambeau, Nicole, committee member; Leisz, Stephen, committee member
American breweries in the nineteenth century offer a business-based lens to understand immigration and industrialization. For this reason, historians in recent years have turned increasing attention to the history of beer, particularly in individual cities such as Chicago or St. Louis. This study examines brewers in Denver from the 1859 Gold Rush to statehood in 1876 and attends to spatial challenges they faced as a result of ethnic and industrial conditions within and far from the city. Over this period, the brewing industry transitioned from several small breweries into a handful of high-producing businesses. Distance to necessary materials, equipment, and customers posed tremendous hurdles to brewers and elicited creative solutions. Breweries thus fulfilled cultural and industrial desires by overcoming geographic obstacles. They condensed space within Denver and the nation through railroads, replaced craftwork with industrial labor, and attempted to structure transitory labor in the American West.
Open Access
Geologic mapping and kinematic analysis of the Independence Mine shear zone in the Sangre de Cristo Range, southern Colorado: extensional reactivation of a Laramide reverse fault
(Colorado State University. Libraries, 2023) Sitar, Michael C., author; Singleton, John, advisor; Ridley, John, committee member; Leisz, Stephen, committee member; Caine, Jonathan Saul, committee member
The Sangre de Cristo Range in southern Colorado records some of the deepest Cenozoic structural levels in the Rocky Mountain region. Exposures of Laramide-age contractional mylonites show evidence for brittle-plastic extensional overprinting associated with the Rio Grande rift. This study examines the relation between Laramide contraction and Rio Grande rift extension by detailed geologic mapping and kinematic, geochronological, and geochemical analyses in a 50 km2 area centered on the Independence Mine shear zone (IMSZ), formerly called the Independence Mine thrust. The IMSZ is a 15- to 100-meter-thick, shallow-to-moderately (25°–62°), WSW-dipping brittle-plastic shear zone near the topographic base of the western flank of the range. It displays microstructural evidence for initiation as a top-NE contractional mylonite zone consistent with Laramide kinematics but is pervasively overprinted by deformation fabrics indicating top-SW extensional reactivation. Top-SW microstructures are characterized by phyllosilicate-lined C- and C'-shear bands and mixed brittle-plastic deformation of quartz. Mapping shows that the IMSZ is the thickest member of a system of mylonitic shear zones that dip shallowly to moderately (25°–67°) to the WSW and are hosted primarily within Proterozoic gneiss. Shear zones in amphibole-rich gneiss are commonly dominated by chlorite whereas those in quartzo-feldspathic gneiss have abundant white mica. Many of the thinner shear zones also record top-SW overprinting of top-NE fabrics. Though both top-NE and top-SW shear fabrics involve cataclasis and quartz dislocation creep, extensional overprinting appears to be mostly restricted to mylonites where secondary phyllosilicates form an interconnected weak phase. These relations are interpreted as fluid-mediated, reaction-weakening gradients where lithologically controlled rheological contrasts were variably sensitive to extensional reactivation. One top-SW shear zone adjacent to the IMSZ cuts a gabbro stock that was dated at 25.7 ± 0.7 Ma using LA-ICP-MS zircon U-Pb geochronometry. Synkinematic monazite grains in two samples of the IMSZ yield LA-ICP-MS U-Pb and U-Th-Pb ages of 24.9 ± 3.0 Ma and 22.2 ± 0.7Ma, respectively. These data are consistent with extensional reactivation occurring during Late Oligocene to Early Miocene time. The IMSZ and associated reactivated shear zones may represent mid-crustal extension that was widespread in the earliest stages of Rio Grande rifting before extension shifted to high-angle brittle-regime normal faults along the range front.
Open Access
GIS-based reservoir planning with limited data in developing nations: a case study of the Lower Mekong River Basin
(Colorado State University. Libraries, 2014) Cvar, Aaron, author; Grigg, Neil S., advisor; Labadie, John, committee member; Fontane, Darrell, committee member; Leisz, Stephen, committee member; Laituri, Melinda, committee member
To view the abstract, please see the full text of the document.
Open Access
Great river wood dynamics in northern Canada
(Colorado State University. Libraries, 2016) Kramer, Natalie, author; Wohl, Ellen, advisor; Rathburn, Sara, committee member; Kampf, Stephanie, committee member; Leisz, Stephen, committee member
Downed wood is a resource easily utilized by plants and animals from the forests to the sea and is essential for many ecosystems. The diverse benefits that wood brings to streams and riparian corridors are well documented by river scientists and wood re-introduction is commonly used as a river restoration tool. However, much of the existing work investigates the short-term impact of wood rather than its variability through time and legacy on the landscape. In this dissertation, I use the Slave River (water discharge=2-7 x103 m3 s −1 , channel widths=300-2000 m, drainage area=6x105 km2 ), and its receiving sedimentary basin, the Great Slave Lake (surface area=273 km2 , depths 20-600 m, volume 1000-2000 km3 ), in northern Canada to better understand wood transport dynamics of a major river basin across varied timescales from minutes to centuries and the influence of driftwood on shoreline landscape evolution. The four primary contributions of this work are: a comprehensive literature review and synthesis of wood transport in rivers worldwide (Chapter 1), new methods for monitoring and quantifying wood flux with timelapse cameras (Chapter 2), description of processes among driftwood, sediment, and vegetation that result in shoreline features that I have coined "driftcretions" (Chapter 3), and expansion of wood transport research into multiple timescales with a focus on how flow history impacts magnitude of wood flux (Chapter 4). In Chapter 1, I: qualitatively summarize existing transport research around flow, wood and reach characteristics, quantitatively consolidate and analyze wood mobility field data in relation to increasing channel size, identify disconnects between driving processes and how mobility is measured, and constrain and conceptualize thresholds between wood dynamic ii regimes. In Chapter 2, I introduce a cheap, useful and fast way to monitor and estimate wood flux with timelapse photography through the use of the metric p, the probability of seeing wood within a timeframe, and I provide statistical methods to estimate appropriate sampling intervals to minimize bias and variance. In Chapter 3, I describe processes and rates by which pulsed driftwood export are delivered and accreted to shorelines and I discuss how these processes influence rates of carbon sequestration, sediment storage and habitat formation. In Chapter 4, I use a variety of methods centered around repeat photography and anecdotes to assess temporal variability of pulsed driftwood flux through the Slave River in the past century. Findings in this dissertation provide useful information for understanding pulsed wood flux, shoreline dynamics and landforms in marine and terrestrial water bodies before widespread historical deforestation, damming of rivers, and wood removal along major waterways. I not only synthesize and link existing work on wood mobilization, transport and deposition to an intriguing case study, but challenge existing wood transport premises, provide new conceptual models describing processes of wood transport through drainage networks, and present new approaches and methods for quantifying and analyzing the variability in wood flux and influence of wood deposits on landforms. My descriptions of wood transport and shoreline processes prior to development of river corridors will be an invaluable resource to groups who seek to identify environmental impacts of dams and to scientists who are investigating the impact that past and future development of river corridors has had or will have on ecosystems.
Open Access
Ground stone lithic technology of the Indian Peaks, Colorado, USA
(Colorado State University. Libraries, 2013) Pelton, Spencer R., author; LaBelle, Jason M., advisor; Leisz, Stephen, committee member; Stolhgren, Thomas, committee member
Ground stone tools are a long-noted aspect of pre-contact archaeological assemblages from the high elevations (2975-3666 meters asl) of the Colorado Front Range (CFR). The tools are present in small frequencies at around 40% of the sites thus far recorded, and are typically present as heavily fragmented grinding slab fragments procured many kilometers east and meters of relief lower than the study area and a combination of local and non-local handstones in a wide array of morphological configurations. Compared to their chipped stone counterparts, ground stone tools typically comprise a small percentage of archaeological assemblages, and have thus been reported in a largely cursory fashion. Though the ground stone assemblage from a single site is too small and perhaps too homogenous to inform large-scale questions, they take on increased interpretive potential when synthesized in aggregate and on a regional scale. Drawing from a distributional approach to archaeology and a technological approach to artifact analysis, the present study addresses the behavioral implications of ground stone tool presence in the high altitudes of the CFR by employing a three-tiered morphological, temporal, and spatial analysis. A technological analysis of ground stone tools (chapter 4) is centered upon answering two primary research questions catered towards understanding the function and technological organization of the high altitude ground stone toolkit. Firstly, the idea that handstones were technologically flexible in function is tested through comparison of the size of and diversity of modifications present on local and non-local handstones. It is determined that non-local handstones are significantly smaller in mass than local handstones, and were thereby chosen for inclusion into mobile toolkits on this basis. However, contrary to expectations of a flexible tool, non-local handstones contain less diversity of modifications than local handstones, suggesting that they were transported for some specialized purpose that local handstones could not fulfill. For netherstones, the idea that some were used as cooking stones is tested, given the assumption that thinner stones would function better for this task and would subsequently exhibit thermal alteration on a more frequent basis. This hypothesis is not proven, suggesting that thermal alteration of grinding slabs is not related to use as cooking stones, or that thickness is not related to grinding slabs' function as cooking stones. A temporal analysis (chapter 5) is conducted to test a prior model of high altitude land use that anticipates a greater diversity of ground stone tool forms will be present in assemblages of early Archaic age, during which residential use of the study area is proposed to have increased in response to climate change. It is determined that, though this period contains the greatest diversity of ground stone tool forms both in terms of handstone morphology and grinding slab thickness, that diversity is almost entirely a function of sample size. The implications of these results are discussed and several needs for future diachronic studies in the region are called for. Finally, a distributional analysis (chapter 6) of ground stone tool presence is undertaken in order to test current models of land use for the Colorado Front Range; the 'rotary' model expects a largely random distribution of ground stone tools and the 'up-down' model expects a largely patterned distribution. It is determined that there are significant differences in the presence of ground stone tools between major ecological zones, and that each zone is provisioned with different ground stone tools types in roughly the same manner. Further, this significant difference is directional, and patterned in terms of the diversity of edible plants located within each ecological zone. These results are interpreted to be most supportive of an 'up-down' model of prehistoric land use.
Open Access
Integrated assessment of agricultural ecosystems using simulation-optimization and machine learning
(Colorado State University. Libraries, 2018) Nguyen, Trung H., author; Paustian, Keith, advisor; Cotrufo, Francesca, committee member; Kelly, Eugene, committee member; Leisz, Stephen, committee member; Davies, Christian, committee member
Agriculture provides many ecosystem services to human society but is also a major cause of environmental degradation. The key challenge of modern agricultural production is to meet projected increases in global demands for food, water, and energy in sustainable ways. Sustainable agricultural production requires integrated decision-support tools and rigorous assessment methods to improve the efficiency of natural resource management while minimizing its impacts to society and long-term ecosystem health. This dissertation focuses on developing methodology and modeling tools to support decision-making for sustainable agricultural resource management. The Millennium Ecosystem Assessment is used as a guiding framework for all the model development. The dissertation balances between the communication of the integrated assessment methodology and the presentation of the modeling techniques through four independent case studies. The first study links biogeochemical models with life cycle assessment (LCA) to explore the impact of regionally-specific ecosystem carbon stock changes associated with cassava cultivation for ethanol production in Vietnam. The second study couples biogeochemical models with GIS and optimization algorithms to conduct a high-resolution, spatially-explicit trade-off analysis of ecosystem services for irrigated corn production systems in the South Platte River Basin, Colorado, USA. The derived modeling platform is named the "Agricultural Ecosystem Service Optimization" (Ag-EcoSOpt). The third study integrates LCA into the Ag-EcoSOpt for a life-cycle-based optimization of feedstock landscape design for a hybrid corn grain- and stover-based ethanol production system at Front Range Energy biorefinery, Windsor, Colorado, USA. The last study develops a surrogate-based optimization framework for Ag-EcoSOpt to reduce the computational burden of large-scale landscape analyses. The study explores the trade-offs among seven management objectives of the irrigated corn production systems in Colorado, USA at different spatial scales.
Open Access
Kilti Pyebwa, the culture of trees: the value of local knowledge in coupled social-ecological systems of rural Haiti
(Colorado State University. Libraries, 2013) McGreevy, John Ryan, author; Browne, Katherine, advisor; Leisz, Stephen, committee member; Reid, Robin, committee member
Haiti's area of forest cover has dropped from 80% to less than 2% since the arrival of foreign influence in 1492. Yet, Haitians remain closely intertwined with the environment, depending on trees for food, shade, building materials, medicine, and protection against hurricanes. Organizations have attempted to reforest Haiti, but 50 years of planting has provided only temporary tree cover. From lack of sustainable outcomes, conservation professionals now acknowledge the need for cultural knowledge and Haitian input. My research addresses these lacking cultural aspects and focuses on the Pwoblem Pyebwa (Tree Problem) in rural Haiti. I have conducted qualitative, iterative research with Haitian research partners and combined this with knowledge from outsiders. Viewing Haiti as a Coupled Social-Ecological System (as local peoples seem to do) has also allowed me to tease out complex processes that foster a cycle of poverty and environmental degradation, which I have named the Pwoblem Pyebwa Cycle. I have also used knowledge from locals and outsiders to situate this cycle in the historical context through the original Pwoblem Pyebwa Model. Doing so has revealed systemic causes of deforestation in Haiti in the form of Initiating Factors (factors that initiated and continue to impact the Cycle) and Catalyzing Factors (factors that perpetuate and increase the magnitude of this Cycle). Lastly, I studied different types of trees in rural Haiti and the local uses of such trees. I conducted this research with the mindset that local peoples hold the most knowledge about their uses of trees and should be treated as teachers and me a student of Haiti. In order to better understand what information is locally specific and what information pertains to the larger Social-Ecological Systems of Haiti, I conducted interviews, participant observation, and focus groups in three rural regions: Deschapelles, Ti Bwa, and Anse Rouge. Each region and each village in these regions had its own set of environmental and social characteristics. Despite these differences, certain commonalities remained constant, and I have set up the Pwoblem Pyebwa Model as a tool to understand the culture of trees across regions of Haiti.
Open Access
Land use restrictions and household transportation choice
(Colorado State University. Libraries, 2016) Mueller, Andrew G., author; Shields, Martin, advisor; Weiler, Stephan, advisor; Mushinski, David, committee member; Leisz, Stephen, committee member
The primary objective of the dissertation is to further existing research on the link between the built environment and travel behavior. The dissertation proposes to make this advance in two distinct ways. First, by testing the impact of land use regulation on travel behavior by incorporating zoning restrictions as an exogenous variable in the model. Second, by explicitly modeling spatial variation in the discrete choice of mode of transportation. The dissertation is organized into three chapters. The first develops a multinomial discrete choice model that addresses unobserved travel preferences by incorporating sociodemographic, built environment, and land use restriction variables. The second builds upon the first by explicitly modeling spatial dependence of travel mode choice in a and compares the results of models from the first and second chapters to address the effect of spatial dependence on travel behavior-built environment model estimates. The third reviews previous models and theories related to land use restrictions, and reviews the economic and policy implications of findings from the first two chapters.
Open Access
Lidar remote sensing of savanna biophysical attributes
(Colorado State University. Libraries, 2015) Gwenzi, David, author; Lefsky, Michael Andrew, advisor; Leisz, Stephen, committee member; Ryan, Michael, committee member; Sibold, Jason, committee member
Although savanna ecosystems cover approximately 20 % of the terrestrial land surface and can have productivity equal to some closed forests, their role in the global carbon cycle is poorly understood. Studies using Light Detection And Ranging (Lidar) have demonstrated the sensor’s ability to measure canopy height, that is in turn strongly related to biophysical attributes such as aboveground carbon storage, but most of this work has focused on closed canopy forests. The sparse observation network in savannas means they remain one of the weak links in our understanding of the global carbon cycle. This study explored the applicability of a past spaceborne Lidar mission and the potential of future missions to estimate canopy height and carbon storage in these biomes. The research used data from two Oak savannas in California, USA: the Tejon Ranch Conservancy in Kern County and the Tonzi Ranch in Santa Clara County. In the first paper we used non-parametric regression techniques to estimate canopy height from waveform parameters derived from the Ice Cloud and land Elevation Satellite’s Geoscience Laser Altimeter System (ICESat-GLAS) data. Merely adopting the methods derived for forests did not produce adequate results but the modeling was significantly improved by incorporating canopy cover information and interaction terms to address the high structural heterogeneity inherent to savannas. Paper 2 explored the relationship between canopy height and aboveground biomass. To accomplish this we developed generalized models using the classical least squares regression modeling approach to relate canopy height to above ground woody biomass and then employed Hierarchical Bayesian Analysis (HBA) to explore the implications of using generalized instead of species composition-specific models. Models that incorporated canopy cover proxies performed better than those that did not. Although the model parameters indicated interspecific variability, the distribution of the posterior densities of the differences between composition level and global level parameter values showed a high support for the use of global parameters, suggesting that these canopy height-biomass models are universally (large scale) applicable. As the spatial coverage of spaceborne lidar will remain limited for the immediate future, our objective in paper 3 was to explore the best means of extrapolating plot level biomass into wall-to-wall maps that provide more ecological information. We evaluated the utility of three spatial modeling approaches to address this problem: deterministic methods, geostatistical methods and an image segmentation approach. Overall, the mean pixel biomass estimated by the 3 approaches did not differ significantly but the output maps showed marked differences in the estimation precision and ability of each model to mimic the primary variable’s trend across the landscape. The results emphasized the need for future satellite lidar missions to consider increasing the sampling intensity across track so that biomass observations are made and characterized at the scale at which they vary. With ICESat-GLAS having been decommissioned in 2010, the earliest planned spaceborne lidar mission is ICESat-2, which will use the Advanced Topography Laser Altimeter System (ATLAS) sensor, which uses a photon counting technique. In paper 4 we explore the capability of this mission for studying three dimensional vegetation structure in savannas. We used data from the Multiple Altimeter Beam Experimental Lidar (MABEL), an airborne photon counting lidar sensor developed by NASA Goddard to simulate ICESat-2 data. We segmented each transect into different block sizes and calculated canopy top and mean ground elevation based on the structure of the histogram of the block’s aggregated photons. Our algorithm was able to compute canopy height and generate visually meaningful vegetation profiles at MABEL’s signal and noise levels but a simulation of the expected performance of ICESat-2 by adjusting MABEL data's detected number of signal and noise photons to that predicted using ATLAS instrument model design cases indicated that signal photons will be substantially lower. The lower data resolution reduces canopy height estimation precision especially in areas of low density vegetation cover. Given the clear difficulties in processing simulated ATLAS data, it appears unlikely that it will provide the kind of data required for mapping of the biophysical properties of savanna vegetation. Rather, resources are better concentrated on preparing for the Global Ecosystem Dynamics Investigation (GEDI) mission, a waveform lidar mission scheduled to launch by the end of this decade. In addition to the full waveform technique, GEDI will collect data from 25 m diameter contiguous footprints with a high across track density, a requirement that we identified as critically necessary in paper 3.
Open Access
Mapping burn severity, pine beetle infestation, and their interaction at the High Park Fire
(Colorado State University. Libraries, 2015) Stone, Brandon, author; Lefsky, Michael, advisor; Rocca, Monique, committee member; Leisz, Stephen, committee member
North America's western forests are experiencing wildfire and mountain pine beetle (MPB) disturbances that are unprecedented in the historic record, but it remains unclear whether and how MPB infestation influences post-infestation fire behavior. The 2012 High Park Fire burned in an area that’s estimated to have begun a MPB outbreak cycle within five years before the wildfire, resulting in a landscape in which disturbance interactions can be studied. A first step in studying these interactions is mapping regions of beetle infestation and post-fire disturbance. We implemented an approach for mapping beetle infestation and burn severity using as source data three 5 m resolution RapidEye satellite images (two pre-fire, one post-fire). A two-tiered methodology was developed to overcome the spatial limitations of many classification approaches through explicit analyses at both pixel and plot level. Major land cover classes were photo-interpreted at the plot-level and their spectral signature used to classify 5 m images. A new image was generated at 25 m resolution by tabulating the fraction of coincident 5 m pixels in each cover class. The original photo interpretation was then used to train a second classification using as its source image the new 25 m image. Maps were validated using k-fold analysis of the original photo interpretation, field data collected immediately post-fire, and publicly available classifications. To investigate the influence of pre-fire beetle infestation on burn severity within the High Park Fire, we fit a log-linear model of conditional independence to our thematic maps after controlling for forest cover class and slope aspect. Our analysis revealed a high co-occurrence of severe burning and beetle infestation within high elevation lodgepole pine stands, but did not find statistically significant evidence that infected stands were more likely to burn severely than similar uninfected stands. Through an inspection of the year-to-year changes in the class fraction signatures of pixels classified as MPB infestation, we were able to observe increases in infection extent and intensity in the year before the fire. The resulting maps will help to increase our understanding of the process that contributed to the High Park Fire, and we believe that the novel classification approach will allow for improved characterization of forest disturbances.
Open Access
Muddy state development in Ghana’s upper east region: one village, one dam, and its effects on smallholder farmers in a study community
(Colorado State University. Libraries, 2023) Roan, Patrick, author; Hausermann, Heidi, advisor; Leisz, Stephen, committee member; Fonte, Steven, committee member; Nyantakyi-Frimpong, Hanson, committee member
Warming trends and drought conditions across northern Ghana portend major implications for water access critical to the future of smallholder farming, food security, and human health. To mediate the impacts of future water resource concerns, the Ghanaian government launched the One Village, One Dam initiative (1V1D) in 2017 which aimed to construct or repair approximately 570 small-scale dams on ephemeral streams in northern communities. Hundreds of dams have been constructed or overhauled to develop northern regions and provide communities with access to water, particularly for dry season farming. This thesis examines the implications of the 1V1D intervention in one study community in Ghana's Upper East Region including social-ecological relationships between smallholders and their farming practices, land-use changes, gold mining, climate data, and farmer perceptions of climate change. My findings reveal that while the government attempted a community-based approach with 1V1D, local insight was marginalized and implementation relied more on outside engineering expertise and State preferences. Most participants contend the dam embankment was poorly designed, improperly located for adequate water capture, and heavy sedimentation including from gold mining is decreasing its capacity. The dam is insufficient for dry season farming, forcing farmers and livestock to depend on wells and boreholes for water, and regional markets for supplemental food supply. Issues of food, water, and economic insecurity are therefore not well addressed by this State development project. A comparative analysis of participant perceptions on climate change is explored and this thesis ends with insights on community ideas for more sustainable climate adaptation interventions.
Open Access
Pedagogical processes and ethnobotanic knowledge on the Pine Ridge Indian Reservation
(Colorado State University. Libraries, 2013) Glenn, Kristina, author; Sherman, Kathleen, advisor; Leisz, Stephen, committee member; Cafaro, Philip, committee member
While observing the processes of engaging participatory-based methods in developing a culturally appropriate approach to environmental education on the Pine Ridge Indian Reservation, this paper seeks to understand the current perceptions that Lakota youth have of their relationship to traditional ecological knowledge and their local ecosystems, and to understand the role that traditional knowledge serves for the participants today.