Department of Forest and Rangeland Stewardship

Permanent URI for this community

https://hdl.handle.net/10217/100430

These digital collections include theses, dissertations, faculty publications, and student publications from the Department of Forest and Rangeland Stewardship. Due to departmental name changes, materials from the following historical departments are also included here: Forest and Wood Sciences; Forest Management and Wood Utilization; Forest, Rangeland, and Watershed Stewardship; Forest Recreation; Forest Recreation and Wildlife Conservation; Forest Sciences; Forestry; Range Management; Range Science; Rangeland Ecosystem Science; Watershed Sciences.

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Open Access
A comparative analysis of wetland and riparian vegetation on Bureau of Land Management land in the western US
(Colorado State University. Libraries, 2023) Binck, Elin, author; Sueltenfuss, Jeremy, advisor; Reynolds, Lindsay, committee member; Smith, Melinda, committee member; Havrilla, Caroline, committee member
In 2011, the BLM deployed its first of three Assessment, Inventory, and Monitoring (AIM) programs as a large-scale, standardized ecological monitoring effort across the agency's land. The first two programs, known as Terrestrial AIM and Lotic AIM, were designed to sample all terrestrial and river ecosystems throughout the landscape. In 2019, the agency piloted its third AIM program, specifically targeting riparian areas and wetlands. This study addressed two main questions: 1) How do wetland and riparian areas sampled with the Terrestrial AIM program compare to those sampled with the Riparian and Wetland (R&W) AIM program, and 2) What are the drivers of plant community composition of the wetlands and riparian areas sampled on BLM land? I developed a set of criteria to identify sites sampled with Terrestrial AIM that had characteristics of wetlands or riparian areas. I then compared vegetation cover, floristic quality metrics, and species composition using nonmetric multidimensional scaling (NMDS) to those sites sampled with R&W AIM. R&W AIM sites had much greater foliar cover, hydrophytic species cover, and perennial cover, but Terrestrial sites had slightly higher floristic metric values. I similarly analyzed the R&W sites on their own, incorporating wetland-specific data that is collected with the new program. I found that sites that met the criteria to be classified as wetlands in the Terrestrial data were a distinct population from the sites sampled with R&W AIM. The main drivers of plant community composition among sites sampled with R&W AIM were elevation and the distribution of surface water, but impacts of grazing were also apparent. All sites assessed by both AIM programs had floristic quality metrics characteristic of highly impacted wetland systems. This study indicates the value of the new R&W AIM program for its ability to perform wetland-specific ecological monitoring, provide valuable data on the health of wetlands, and provide baseline condition that can help guide land management practices into the future.
Open Access
A geospatial framework to assess fireline effectiveness for large wildfires in the western USA
(Colorado State University. Libraries, 2020-08-18) Gannon, Benjamin M., author; Thompson, Matthew P., author; Deming, Kira Z., author; Bayham, Jude, author; Wei, Yu, author; O'Connor, Christopher D., author; Fire, publisher
Quantifying fireline effectiveness (FLE) is essential to evaluate the efficiency of large wildfire management strategies to foster institutional learning and improvement in fire management organizations. FLE performance metrics for incident-level evaluation have been developed and applied to a small set of wildfires, but there is a need to understand how widely they vary across incidents to progress towards targets or standards for performance evaluation. Recent efforts to archive spatially explicit fireline records from large wildfires facilitate the application of these metrics to a broad sample of wildfires in different environments. We evaluated fireline outcomes (burned over, held, not engaged) and analyzed incident-scale FLE for 33 large wildfires in the western USA from the 2017 and 2018 fire seasons. FLE performance metrics varied widely across wildfires and often aligned with factors that influence suppression strategy. We propose a performance evaluation framework based on both the held to engaged fireline ratio and the total fireline to perimeter ratio. These two metrics capture whether fireline was placed in locations with high probability of engaging with the wildfire and holding and the relative level of investment in containment compared to wildfire growth. We also identify future research directions to improve understanding of decision quality in a risk-based framework.
Open Access
A landscape-scale investigation into the risk of lodgepole pine mortality caused by mountain pine beetle Dendroctonus ponderosae (Coleoptera: Curculioidae: Scolytinae)
(Colorado State University. Libraries, 2010) Johnson, Erik W., author; Reich, Robin M., advisor; Negron-Segarra, Jose F., 1960-, committee member; Jacobi, William R., committee member
Mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, is currently causing Pinus contorta Douglas (LP) mortality in several areas of western United States and Canada at high levels including portions of Colorado. For decades, researchers have developed models to help land managers predict when and where MPB infestation will develop based on forest structure, tree size, tree age and geographic characteristics; these models were developed at the stand-level for stand-level analysis. Land managers and planners have become increasingly interested in predicting MPB risk and susceptibility at the landscape-scale; however attempts at landscape-scale modeling have proven difficult as continuous forest mensuration datasets are often lacking. Techniques for producing low-cost, high-resolution, landscape-scale forest composition and forest structure Geographic Information System (GIS) layers were demonstrated by this study. These GIS layers were subsequently used to assess several existing MPB risk models, at the landscape-scale, and to derive a new empirical MPB model. The procedures outlined in this paper describe the generation of landscape-scale forest composition and structure GIS layers (predictive surfaces) based on recent and innovative remote sensing and spatial statistical techniques. These techniques transform a small field sample into a continuous GIS surface utilizing multiple linear regression and binary regression trees. Information derived from satellite imagery and digital elevation models are used as auxiliary variables to assist in the prediction of response variables (basal area, proportion of lodgepole pine basal area, diameter at breast height, quadratic mean diameter, percent canopy closure, and trees per acre). A carefully designed field sample, stratified by Landsat image spectral groupings, optimized sampling faculties by maximizing between-stratum variability while minimizing within-stratum variability. Forest composition (spatial distribution of tree species), basal area, proportion of lodgepole pine basal area, diameter at breast height, quadratic mean diameter, percent canopy closure, and trees per acre predictive surfaces were developed for Colorado's Fraser River Valley. These predictive surfaces were then used to assess the landscape-scale predictive capabilities of following MPB prediction models: Anhold et al., (1996), Amman et al. (1977), Shore and Safranyik (1992), and the USDA Forest Service National Insect and Disease Risk Map. Finally, a new MPB model is described based on geographic factors, the predictive surfaces, and recent occurrence of mountain pine beetle caused-tree mortality.
Open Access
A modeling approach to estimating snow cover depletion and soil moisture recharge in a semi-arid climate at two NASA CLPX
(Colorado State University. Libraries, 2004) Holcombe, Julie D., author; Fassnacht, Steven R., advisor
Snow cover depletion and soil moisture recharge are small segments, but crucial hydrological components for cryospheric regions of the earth. The abilities of a one-dimensional mass and energy balance model (SNTHERM) to predict snow cover depletion and Fast All season Soil STrength (FASST) to model the evolution of soil moisture recharge based on observed data from two NASA Cold Land Processes Experiment (CLPX) sites were evaluated. The objective was to investigate both model accuracies in predicting the observed parameters at Buffalo Pass near Steamboat and Illinois River located in North Park, both of which are located in the Colorado Rocky Mountains and are known for their differences in terrain and weather conditions. The results from SNTHERM and FASST and the model performance statistics illustrate that the models overall fit to the observations were excellent at both locations. SNTHERM predicted the snow cover depletion date two days later than the observations at Buffalo Pass and only one day prior to the observations at Illinois River. The timing of snow accumulation and melt at Illinois River was in agreement with the observations at Illinois River, but the magnitude of snow depth was incorrect. The shallow and patchy nature of snow cover and the inconsistent meteorological parameters were problematic for SNTHERM. FASST correctly predicted the magnitude of seasonal soil moisture storage at both sites, but soil moisture recharge prediction was challenging for the model. A lateral flow module and thorough soil data are thought to improve FASST's capability to predict the timing of soil moisture change. SNTHERM and FASST prove to possess the ability to predict snow cover depletion and seasonal soil moisture storage at two radically different field sites.
Open Access
A spatial stochastic programming model for timber and core area management under risk of stand-replacing fire
(Colorado State University. Libraries, 2012) Nguyen, Dung Tuan, author; Wei, Yu, advisor; Bevers, Michael, committee member; Kling, Robert W., committee member
Forest harvest scheduling has been modeled using deterministic and stochastic programming models. Past models seldom address explicit spatial forest management concerns under the influence of natural disturbances. In this research study, we employ multistage full recourse stochastic programming models to explore the challenges and advantages of building spatial optimization models that account for the influences of random stand-replacing fires. Our exploratory test models simultaneously consider timber harvest and mature forest core area objectives. Each model run reports first-period harvesting decisions for each stand based on a sample set of random fire. We integrate multiple model runs to evaluate the persistence of period-one solutions under the influence of stochastic fires. Follow-up simulations were used to support multiple comparisons of different candidate forest management alternatives for the first time period. Test case results indicate that integrating the occurrence of stand-replacing fire into forest harvest scheduling models could improve the quality of long-term spatially explicit forest plans.
Open Access
A stochastic mixed integer program for modeling wildfire behavior and optimizing fire suppression operations
(Colorado State University. Libraries, 2014) Belval, Erin Jean McCowen, author; Wei, Yu, advisor; Bevers, Michael, committee member; Reich, Robin, committee member; Labadie, John, committee member
Wildfire suppression decisions combine multiple objectives and risk management to form a complex background against which decision makers attempt to determine efficient management actions in a short period of time. Their decisions are necessarily dynamic in nature as a sequence of random events unfolds at each fire. This dissertation presents a stochastic mixed integer program with full recourse to simulate spatially explicit fire behavior for a single fire representing a distribution of probable changes in behavior in response to weather changes. Suppression decisions and fire behavior respond dynamically to these weather events and to each other. Initially, a deterministic mixed integer program is developed to explore how to integrate spatial fire behavior with suppression actions into a mathematical programming framework. The model uses a raster landscape. Fire behavior includes fire arrival time and fireline intensity at each cell and the minimum travel time path by which fire reached the cell. Spatially explicit fireline intensities and arrival times are dependent upon the fire spread paths, therefore fire suppression actions that change the minimum travel time path also change the fireline intensity and arrival time. Weather is modeled as constant. Test cases for the deterministic model provide examples of spatially explicit fire behavior and corresponding optimal suppression strategies for a variety of suppression levels. Next, a stochastic mixed integer program is developed that expands upon the capabilities of the deterministic model. The stochastic model allows uncertain fire behavior to be simulated by referring to probabilistic weather decision trees. The fire behavior in the stochastic model interacts dynamically with both weather changes and suppression decisions. Constraints are included to characterize fire as ecologically beneficial or harmful based upon the fireline intensity, which allows the model to examine multiple policy objectives. A selection of alternative policy objectives is modeled in test cases, including minimizing the total expected area burned, minimizing the expected area burned at an ecologically harmful fireline intensity, maximizing the expected area burned at an ecologically beneficial fireline intensity, and minimizing expected fireline production. Explicit nonanticipativity constraints ensure that the model produces suppression decisions that account for uncertainty in weather forecasts. In the final model formulation, detailed fire control constraints are incorporated into the stochastic mixed integer fire growth and behavior program to model more realistic suppression decisions. These constraints account for spatial restrictions for fire crew travel and operations; for example, a crew's travel path must be continuous. Crew safety is also addressed; crews must keep a safety buffer zone between themselves and the fire. Fireline quality issues are accounted for by comparing control line capacity with fireline intensity to determine when a fireline will hold. The model lets crews work at varying production rates throughout their shifts, giving the model the flexibility to fit work assignments with the predicted fire behavior.
Open Access
A triadic relationship on the northern Great Plains: bison (Bison bison), native plants, and native people
(Colorado State University. Libraries, 2007) Garrett, James J., author; Woodmansee, Robert G., advisor
The dissertation investigates and documents the historic relationship that exists among Bison bison, native plants, and Native People. An exhaustive in-depth review of each ecological component is given. Lakota Indian participants were interviewed for their qualitative knowledge of the three ecological components being studied. Interviewees were selected for their individual expertise in ethnobotany. Lokota culture, and/or indigenous ecological knowledge. Participant contributions are synthesized into a running narrative that describes the relationship in intimate detail. Detailed analysis shows that there are many facets to the relationship that exists among the three major ecological components. Recommendations are made for further research and the appendices include Lokota terminology, interview protocol and questions, data codes, and maps of Lakota territory before and after colonization.
Open Access
Aboveground woody biomass estimation of green ash trees (Fraxinus pennsylvanica Marsh.) along Colorado's Northern Front Range in response to the invasive emerald ash borer (Agrilus plannipenis Fairmaire)
(Colorado State University. Libraries, 2018) Truslove, Micaela, author; Mackes, Kurt, advisor; Nagel, Linda, advisor; Davis, Seth, committee member; Paustian, Keith, committee member; Wood, Keith, committee member
The invasive emerald ash borer (Agrilus planipennis Fairmaire) has killed hundreds of millions of ash trees (Fraxinus spp.) in forests and urban areas across the United States. Green ash (Fraxinus pennsylvanica Marsh.) is the most widely planted street tree in the greater Denver Metro Area, comprising 15% of the urban tree population on a per-stem basis, and up to 33% of the canopy cover in some cities. EAB is currently established in Boulder, Colorado and as the infestation progresses along the Colorado Northern Front Range, municipalities will need to predict and budget for woody debris disposal from EAB-killed trees. Though existing green ash biomass predictive equations exist, most were developed for areas outside the arid West and generally represent only trees in natural forests, with full, healthy crowns. This study aimed to test whether these equations can accurately predict aboveground woody biomass of green ash trees removed as part of emerald ash borer mitigation efforts in urban areas of Colorado's Northern Front Range. Data from 42 destructively sampled ash trees removed from 11 sites as part of emerald ash borer mitigation efforts were used to evaluate the predictive capability of 12 forest-derived and five urban green ash biomass equations. The published urban equations underpredicted total sampled biomass by as much as 38% and overpredicted by as much as 47%. Forest-derived equations underpredicted by as much as 57% and overpredicted up to 52%. A local, published equation developed in the Northern Front Range overpredicted biomass by 47%. This local urban equation was developed using only open-grown trees with full, healthy crowns while the trees sampled for this study exhibited a broad spectrum of crown conditions, better representing trees that will routinely be removed as part of emerald ash borer management strategies. Sampled trees were also used to develop new local green ash biomass equations, more appropriate for use in emerald ash borer management strategies in Colorado's Northern Front Range cities. In addition, the locally-derived average specific gravity value for green ash wood was 0.57, and the locally-derived average moisture content value was 41%. These are 7.5% higher and 24% lower respectively than widely-used published values. The locally-derived values can be used to further improve the accuracy of urban forest mensuration efforts in Colorado's Northern Front Range.
Open Access
Advancing prescribed fire science through numerical simulation and improved reporting practices
(Colorado State University. Libraries, 2022) Bonner, Sophie R., author; Hoffman, Chad, advisor; Linn, Rodman, committee member; Tinkham, Wade, committee member; Rocca, Monique, committee member
Planning a prescribed burn that is safe and effective relies on land managers understanding how a complex suite of interactions between the burning environment (e.g., fuels, fire weather, and topography) and ignition factors influence fire behavior and effects. As the field of prescribed fire science has grown, more questions have arisen regarding how the spatial structure of forests and the ignition pattern affect the ecological outcomes of these burns. Advancing our understanding of these factors is crucial to provide managers with quality, evidence-based science that can inform prescribed fire planning. In this two-part thesis, my objectives were: i) to evaluate reporting quality in recent prescribed fire literature and suggest minimum reporting standards for future prescribed fire experiments, and ii) to explore the potential effects of complex forest fuel structures and ignition patterns on fire behavior and the resultant ecological effects during prescribed burns. In Chapter 1, I present results from a literature review of reporting standards from over 200 prescribed fire experiments conducted from 2016 to 2020. My results suggest substantial shortcomings in the reporting of critical data that limit the utility of prescribed fire research. Specifically, I found that specific information on burning conditions such as fuel moisture (22%), quantitative fuel loads (36%), fire weather (53%), and fire behavior (30%) were often not reported by the authors. Further, I found that only 54% of the studies provided descriptions of the ignition characteristics. Given these common deficiencies, suggested minimum reporting standards are proposed for future prescribed fire experiments which can be used to increase the quality, applicability, and reproducibility of prescribed fire science, facilitate future research syntheses, and foster actionable science. In Chapter 2, I evaluate how forest structural complexity and ignition pattern impact crown damage during simulated prescribed fires in longleaf pine (Pinus palustris) dominated forests of the southeastern United States. My results show that - regardless of forest structure – using a strip-head ignition pattern consistently produced more crown damage than spot-head or alternative spot-head ignition patterns. In terms of forest structure, I found forests with greater structural complexity resulted in more crown damage than less complex forests. More specifically, I observed forests with more aggregated horizontal spatial patterns, greater vertical complexity, and moderate to high amounts of canopy cover to produce more severe fire behavior than regularly spaced, single-story forests with sparse canopy cover. These findings suggest that managers need to consider a forest's structure and their choice of ignition pattern when planning prescribed burns to ensure they meet ecological objectives.
Open Access
Alkaline/peracetic acid as a pretreatment of lignocellulosic biomass for ethanol fuel production
(Colorado State University. Libraries, 1998) Teixeira, Lincoln Cambraia, author; Crews, Donald L., advisor; Schroeder, Herbert A., committee member; Linden, James C., committee member; Wangaard, Frederick F., committee member
Peracetic add is a lignin oxidation pretreatment with low energy input by which biomass can be treated in a silo type system for improving enzymatic digestibility of lignocellulosic materials for ethanol production. Experimentally, ground hybrid poplar wood and sugar cane bagasse are placed in plastic bags and a peracetic acid solution is added to the biomass in different concentrations based on oven-dry biomass. The ratio of solution to biomass is 6:1; after initial mixing of the resulting paste, a seven-day storage period at about 20 °C is used in this study. As a complementary method, a series of pre-pretreatments using stoichiometric amounts of sodium hydroxide and ammonium hydroxide based on 4-methyl-glucuronic acid and acetyl content in the biomass is been performed before addition of peracetic acid. The alkaline solutions are added to the biomass in a ratio of 14:1 solution to biomass: the slurry is mixed for 24 hours at ambient temperature. The above procedures give high xylan content substrates. Consequently, xylanase/beta- glucosidase combinations are more effective than cellulase preparations in hydrolyzing these materials. The pretreatment effectiveness is evaluated using standard enzymatic hydrolysis and simultaneous saccharification and cofermentation (SSCF) procedures. Hybrid poplar wood pretreated with 15 and 21% peracetic acid based on oven- dry weight of wood gives glucan conversion yields of 76.5 and 98.3%, respectively. Sugar cane bagasse pretreated with the same loadings gives corresponding yields of 85.9 and 93.1%. Raw wood and raw bagasse give corresponding yields of 6.8 and 28.8%, respectively. The combined 6% NaOH/15% peracetic acid pretreatments increase the glucan conversion yields from 76.5 to 100.0% for hybrid poplar wood and from 85.9 to 97.6% for sugar cane bagasse. Respective ethanol yields of 92.8 and 91.9% are obtained from 6% NaOH/15% peracetic acid pretreated materials using recombinant Zymomonas mobilis CP4/pZB5. Peracetic acid pretreatment improves enzymatic digestibility of hybrid poplar wood and sugar cane bagasse. Based on reduction of acetyl groups in the two lignocellulosic materials, alkaline pre-pretreatments are helpful in reducing peracetic acid requirements in the pretreatment and consequently diminishing growth inhibition of the bacteria that was observed using higher peracetic acid loadings.
Open Access
An integrated eco-socio-economic analysis of forest transition and forest restoration in Vietnam
(Colorado State University. Libraries, 2018) Khuc, Quy Van, author; Paschke, Mark W., advisor; Pham, Dien V., advisor; Loomis, John B., committee member; Cheng, Antony S., committee member
Forests provide numerous benefits to human well-being, so changes in forest cover have large societal impacts from local to global scales. Several studies in Vietnam and elsewhere have found single solutions for increasing forest cover. However, a comprehensive solution for harnessing forest restoration to satisfy growing demands for sustainable global development that improves rural community livelihood, enhances biodiversity and environmental services, and mitigates climate change is lacking. This dissertation focuses on obtaining a deeper understanding of forest transition, forest restoration, and their proximate drivers as well as trade-offs of land use in upland forests in Vietnam. This dissertation is a collection of four independent studies. The first study quantified the drivers of deforestation and forest degradation at a national scale in Vietnam. Results show that around 1.77 and 0.65 million hectares of forests were lost or degraded, respectively, between 2000 and 2010. Deforestation and forest degradation declined in Vietnam between 2000 and 2010, but these processes remain significant. The extent and magnitude of deforestation and degradation vary across provinces and were most notable in the north central, northeast, central highland, and northwest areas of the nation. Poverty, initial forest cover, governance, and population growth were the top drivers of deforestation and degradation. The second study investigated the extent of forest restoration and its proximate drivers at the local-communal scale in Vietnam's Dien Bien Province. Geographic information system (GIS) tools, a structural regression model based on forest cover maps, and a field survey were employed while numerous socio-economic variables that were potentially associated with forest restoration were examined. I found that around 118,000 hectares of forests were restored between 1990 and 2010. Restored forest comprised the largest share (above 84%) of total forest gain and this share increased from 1990-2000 to 2000-2010. Expansion of restored forest was mainly driven by the presence of migration, lower population density, higher income, and the implementation of forestry policies. The third study explored the willingness of urban households to support forest restoration in Vietnam. I randomly surveyed over 200 households in the capital city Hanoi and a maximum likelihood estimator model was used to obtain the parameters of a model to quantify willingness-to-pay (WTP) for a program of forest restoration. Over forty percent of the households surveyed were willing to pay for forest restoration. As well as quantified determinants of WTP, my findings suggest that either improving households' income and educational level or focusing on females in the family may represent untapped sources of restoration funding among urban households. Finally, in a fourth study, the potentials and challenges of climate change mitigation programs in the north central region of Vietnam demonstrate possible scenarios associated with many levels of uncertainty. The role of plantation forests in total household income was quantified, trade-offs between shifting cultivation and plantation forests were analyzed and the factor groups that constrain plantation forest expansion were highlighted. My empirical results offer several important policy implications, not only for forest restoration practices as part of forest-based climate change mitigation programs but also for sustainable mountainous rural livelihood development in Vietnam and beyond.
Open Access
An investigation of nitrogen fixation by Russet buffaloberry in Colorado conifer forests
(Colorado State University. Libraries, 2011) Miller, Zoe May, author; Paschke, Mark W., advisor; Binkley, Daniel E., committee member; Rhoades, Charles C., committee member; Stromberger, Mary E., committee member
Russet buffaloberry (Shepherdia Canadensis (L.) Nutt.) is an actinorhizal shrub capable of forming a symbiotic relationship with the N2-fixing soil actinomycetes Frankia. Actinorhizal shrubs are important species as they are able to fix an ecologically significant amount of N and can inhabit disturbed sites with infertile soils. Buffaloberry is commonly found as a dominant understory species in lodgepole pine (Pinus contorta Douglas ex Louden) communities and is a common post-fire disturbance species. There is a lack of information regarding buffaloberry's ability to fix atmospheric N2 in Colorado forests. This study used the 15N natural abundance method in a survey of buffaloberry in north central Colorado to determine the percent of foliar N that buffaloberry derives from fixation (%Ndfa) and how fixation may be affected by local environmental factors. The mountain pine beetle (Dendroctonus ponderosae) epidemic is currently responsible for large losses in lodgepole pine forests. As the overstory canopies of lodge pole pine communities die off, there is an increase in available light in the understory. I investigated buffaloberry's response to light availability because with more photosynthetic activity, buffaloberry could potentially have more energy to expend in the energy intensive N2-fixation process. 59 plots (0.1-ha) were sampled in July 2009 and were distributed among Larimer, Jackson, and Grand counties in Colorado. Buffaloberry (15N: ‒0.63 /, N: 3.48%) had a 15N abundance closer to the atmospheric standard with high foliar %N content as compared to non-N2-fixing reference species (15N: ‒.29- ‒4.81 / N: 1.11-3.20%), indicating biological N2-fixation. I estimate a probable range of foliar %N derived from biological fixation as 60-100%. Buffaloberry (2.65%) also had higher % foliar N as compared to the reference species (1.50%) in the autumn, just before leaf abscission. There were no significant correlations between light availability and N2-fixation by buffaloberry suggesting that N2-fixation in buffaloberry may not benefit from an increase in light availability.
Open Access
Artificial intelligence based decision support for trumpeter swan management
(Colorado State University. Libraries, 2002) Sojda, Richard S., author; Dean, Denis J., advisor; Fredrickson, Leigh H., committee member; Howe, Adele E., committee member; Loomis, John B., committee member
The number of trumpeter swans (Cygnus buccinator) breeding in the Tri-State area where Montana, Idaho, and Wyoming come together has declined to just a few hundred pairs. However, these birds are part of the Rocky Mountain Population which additionally has over 3,500 birds breeding in Alberta, British Columbia, Northwest Territories, and Yukon Territory. To a large degree, these birds seem to have abandoned traditional migratory pathways in the flyway. Waterfowl managers have been interested in decision support tools that would help them explore simulated management scenarios in their quest towards reaching population recovery and the reestablishment of traditional migratory pathways. I have developed a decision support system to assist biologists with such management, especially related to wetland ecology. Decision support systems use a combination of models, analytical techniques, and information retrieval to help develop and evaluate appropriate alternatives. Swan management is a domain that is ecologically complex, and this complexity is compounded by spatial and temporal issues. The Distributed Environment Centered Agent Framework (DECAF) was successful at integrating communications among agents, integrating ecological knowledge, and simulating swan distributions through implementation of a queuing system. The work I have conducted indicates a need for determining what other factors might allow a deeper understanding of the effects of management actions on the flyway distribution of waterfowl. Knowing those would allow the more refined development of algorithms for effective decision support systems via collaboration by intelligent agents. Additional, specific conclusions and ideas for future research related both to waterfowl ecology and to the use of multiagent systems have been triggered by the validation work.
Open Access
Aspen forests on the Uncompahgre Plateau: current and future expectations
(Colorado State University. Libraries, 2012) Alsanousi, Attia A. Mussa, author; Binkley, Daniel, advisor; Smith, Frederick W., committee member; Sibold, Jason S., committee member
Dynamic changes in aspen cover on the Uncompahgre Plateau have raised concerns among researchers and communities about the stability and long-term survivorship of aspen forests. In the summer of 2010, aspen increment cores were measured for current age distribution from sixty-three random locations across the Plateau including pure aspen and mixed conifer- aspen stands, to provide insights about aspen forests in the near future. Most of aspen trees on the Plateau in 2010 were 100 to 130 years old, and having established after the last major landscape-scale fire in 1879. Trees older than 140 years accounted for about 2% of all stems, with the oldest tree in our random sample being 272 years at breast height. Aspen cover will likely decline over the next five decades, as young cohorts (<80 years) have fewer stems than older cohorts (100- 130 years). Several ecological processes or events could accelerate aspen decline, including conifer replacement of aspens in mixed stands and severe drought. The three survivorship scenarios showed that the reduction in aspen cover by 2060 will likely vary from about 40% of current aspen cover in the most optimistic scenario to a 84% reduction in a higher mortality scenario. The Plateau currently has abundant numbers of aspen suckers, but few of these escape browsing pressure to become trees. The aspen decline predicted in the scenarios may continue beyond 2060 if recruitment remains low, or could be turned around if widespread disturbance regenerates forests, or if browsing pressure drops substantially.
Open Access
Assessing forest plan revision under the 2012 planning rule: understanding policy implementation and organizational learning
(Colorado State University. Libraries, 2017) Ricco, Gwendolyn M., author; Schultz, Courtney, advisor; Rocca, Monique, committee member; Williams, Dan, committee member
In 2012, under the National Forest Management Act (NFMA), the U.S. Forest Service promulgated a new planning rule that was a significant change from past planning regulations. For example, the concepts of ecological integrity and climate change adaptation were introduced as important management priorities. This research identified lessons learned, innovations, and best practices under the 2012 planning rule and characterized how organizational learning occurred during times of policy transition and implementation. I used learning frameworks to identify types of learning occurring. In addition, early policy implementation is a critical time for an organization to experience learning, but there has been relatively little literature that looks at how learning occurs during this period. The policy implementation literature discusses both top-down and bottom-up variables impacting implementation, and I considered how these may also affect learning. We collected qualitative data from the 2016 Planners' Meeting in Fort Collins, Colorado held by the Forest Service and conducted 25 semi-structured, follow-up interviews with planning staff to understand what types of learning were occurring during early implementation of a new policy, determine how the factors that affect policy implementation affect learning, and identify how the agency could better support learning throughout the implementation of the 2012 planning rule. This study revealed that although the Forest Service is displaying some characteristics of a learning organization, such as creating social learning networks, the agency needs structural and cultural changes to reach their goals and overcome barriers. Much of the learning that is occurring happens at the individual level, and a critical challenge is how to improve diffusion and consolidation of the knowledge being gained. Therefore, the agency will need to create entirely new structures to capture their knowledge and lessons learned to better encourage continual learning. This could include improving trainings and workshops and offering mentoring opportunities but may also require reorganization and dedication of new staff positions to support more effective organizational learning.
Open Access
Assessing post-fire tree regeneration and forest conversion across an elevational gradient in southern Colorado
(Colorado State University. Libraries, 2023) Hastings, Amanda K., author; Stevens-Rumann, Camille, advisor; Fornwalt, Paula, committee member; Rocca, Monique, committee member
Increased wildfire activity, with anticipated novel climate scenarios, raises concerns about forest resilience—particularly in semi-arid regions of the western US. Specifically in southwestern US and Southern Rocky Mountain forests, lack of conifer seed sources and shifts in temperature or precipitation post-wildfire may limit the recruitment of dominant conifer species. Meanwhile, hotter and drier conditions may promote the proliferation of resprouting angiosperm species, resulting in vegetative type conversions. To better understand forest susceptibility to type conversion following wildfire, I assessed early vegetation assembly 3 years post-fire, in sites that burned at low and high severity and spanned a climatic gradient in the Sangre de Cristo range of southern Colorado. Research sites were located in lower montane, upper montane, and subalpine forests, with relative dominances of Pinus ponderosa- Pseudotsuga menziesii; Abies concolor- Pinus contorta- Populus tremuloides; and Abies lasiocarpa- Picea engelmannii- Pinus flexilis- Pinus aristata; respectively. I quantified post-fire tree seedling densities and other site-specific attributes to evaluate a) how do burn severity and forest type influence early post-fire tree regeneration, b) are these forest types undergoing conversions? and c) if so, what factors are driving type-conversion?In this early assessment, I found concerns of forest conversion may be warranted for lower montane forests, with greater abundances of deciduous tree-shrub species, Quercus gambelii and Robinia neomexicana, and high shrub cover. Meanwhile, upper montane forests are likely regenerating to a similar forest composition, with early Populus tremuloides dominance and Pinus contorta regeneration. For both lower and upper montane forest types, conifer regeneration was positively correlated with legacies of low-moderate severity fire, such as overstory cover and litter/woody debris. Meanwhile, subalpine tree regeneration was driven by site-climate and topographic position, regardless of fire severity. In subalpine forests, this study suggests early post-fire conifer regeneration may be dominated by xeric and drought-tolerant species, Pinus flexilis, Pinus aristata, and Pinus contorta, where decades may pass before the establishment of shade-tolerant species characteristic of this forest type. Across all forest types, greater time is required in the post-fire period to predict ultimate recovery trajectories. However, this study serves as one of the first within southern Colorado to evaluate post-fire regeneration across a full elevational gradient and multiple forest types within a single fire footprint.
Open Access
Assessing vegetation reestablishment on disturbed high mountain lakeshores following historic dam removal in Rocky Mountain National Park, Colorado, USA
(Colorado State University. Libraries, 2016) Goodrich, Amy C., author; Paschke, Mark, advisor; Meiman, Paul, advisor; Steingraeber, David A., committee member; Jonas-Bratten, Jayne, committee member
Dam removal has entered the public spotlight in recent years, due to growing safety, economic, and environmental concerns related to dams. Removal is increasingly seen as a way to address not only the risks associated with aging and/or obsolete dams, but also as a tool for ecological restoration. In 1982, then-79-year-old Lawn Lake Dam in Rocky Mountain National Park failed, resulting in three deaths, and extensive monetary damages and destruction of natural resources within the Park. This was followed by a policy decision to remove three dams in the Park between 1988 and 1990, returning the former reservoirs to their previous natural lake water levels, and re-exposing nearly 13 hectares of scoured shoreline, completely denuded of vegetation by approximately 80 years of inundation. The disturbed lakeshore areas were left to undergo passive restoration. In the years immediately following dam removal, one short-term (3 year) revegetation study was conducted at Lawn Lake, and informal observational data were gathered by NPS personnel at a handful of plots established at the disturbed lakeshores of Bluebird, Sandbeach, and Pear Lakes. However, no further published analyses of data were made available, and until 2014 the vegetation at these lakeshores had not been surveyed to determine longer-term effects of damming and dam removal to reestablished vegetation. The goal of this study was to identify any persisting effects of historic damming and subsequent dam removal on vegetation characteristics such as species richness and diversity and community composition in the previously submerged lake margin areas surrounding the formerly dammed lakes, as well as the more elevated surrounding areas that had not been inundated. To do this, in July to September of 2014 I conducted surveys of vascular plant cover by species in 150 plots at nine high mountain lakes, including the four formerly dammed lakes and five undammed reference lakes. Site-specific environmental variables slope, aspect, elevation, elevation above current waterline, and soil texture were recorded at each plot. Plots were categorized as “elevated” or “lake margin” based on an elevation cutoff from the current waterline, to separate plots that had been previously submerged at dammed lake sites from more elevated sites that had not. I analyzed data from plots in each category for the effect of lake type (formerly dammed or reference) by fitting linear mixed models to species richness and diversity response. I performed a hierarchical cluster analysis that identified eight distinct vegetation communities, and performed non-metric multi-dimensional scaling (NMS) to explore relationships between vegetation community composition and site-specific measured environmental variables. No significant differences in vegetation characteristics of the elevated areas were found between formerly dammed and reference lakes. In previously submerged areas of formerly dammed lakes, however, species richness was significantly higher, compared to the similarly-located lake margin areas surrounding reference lakes (+3.361, χ2=8.919, p-val=0.003). All eight identified vegetation communities occurred at both formerly dammed and reference lakes. Slope and elevation were the measured environmental variables most strongly correlated with NMS axes (cumulative r2 values of 0.18 and 0.086), indicating that they are the most influential measured environmental variables in structuring plant communities at these study sites.
Open Access
Assessing wildlife habitat suitability for ecological sites and state and transition models
(Colorado State University. Libraries, 2011) Hibbs, Willow Bo, author; Roath, Roy, advisor; Fernandez-Gimenez, Maria, committee member; Noon, Barry, committee member
Wildlife habitat is an important component of rangeland management plans. Unfortunately, there are few practical tools to assist managers in understanding how management and environmental variation affects habitat suitability. Ecological site descriptions (ESDs) have the potential to fill this role because they contain information on the biophysical features of the land and contain state-and-transition models (STMs) which describe ecological sites in terms of their potential vegetation dynamics. These characteristics can be the primary indicators of suitable wildlife habitat. Researchers and managers using ESDs and STMs have suggested that information on other aspects of ecosystem functions should be included so that they can be evaluated along with soils and vegetation. I developed greater sage grouse (Centrocercus urophasianus) and mule deer (Odocoileus hemionus) habitat models using published literature and a fuzzy logic knowledge representation and evaluation system. The resulting outputs were 0-1 scaled indices representing the relative suitability of habitat based on measured habitat attributes in different states of two ecological sites common in NW Colorado, claypan and mountain loam. In Chapter 1, I tested hypotheses related to the habitat suitability of differing states in these two structurally divergent ecological sites. Results support the hypotheses that states with degraded attributes or that were associated with aerial herbicide spraying are generally lower in habitat suitability, and that states with similar components as the reference state do not have significantly different habitat suitability than the reference states. In Chapter 2, I developed sage grouse habitat maps and compared the results with current habitat mapping procedures. The ecological site/STM framework allowed for an understanding of the distribution, abundance, and value of habitat to be linked to management and environmental variation. This work is an important contribution towards incorporating wildlife habitat information into ESDs and understanding trade-offs in wildlife habitat suitability associated with different vegetation states.
Open Access
Assessment of digital land cover maps for hydrological modeling of the Yampa River Basin, Colorado, USA
(Colorado State University. Libraries, 2005) Repass, Julie Mae, author; Fassnacht, Steven R., advisor
In order to produce satisfactory results from hydrologic models, it is imperative to use good input data. Today there is a multitude of different land cover maps available, and determining which input data map for the model can be unclear. The goal of this study was to quantify the differences between several readily available land cover maps to determine their relative suitability for hydrological modeling of the Yampa River Basin, Colorado. The land cover maps compared in this study are derived from Advanced Very High Resolution Radiometer (AVHRR), Landsat Thematic Mapper (TM), and Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. These maps were compared to a 30-m land cover map modeled from ground data, Landsat imagery, and MODIS imagery, all collected in 2004. This map was regarded as "truth" in this study due to its fine resolution and use of recent ground data and imagery, and was used to rank the public domain land cover data sets. In order to compare the different land cover data sets, all data were first degraded to a common spatial resolution (~30-m) and a common species resolution. Once this was accomplished, the maps were assessed on four levels. The four assessments were based on: (i) the relative agreement of the total aggregated land class percentages after the data had been cross-walked with respect to the reference map; (ii) pixel accuracy; (iii) scene accuracy; and (iv) cumulative streamflow model output from the United States Geological Survey (USGS) Precipitation-Runoff Modeling System (PRMS) in relation to observed cumulative streamflow. The results showed that the pixel and scene accuracies did not correlate with model performance within the Yampa River Basin using the PRMS model. The qualitative comparison of the total aggregated land class percentages helped explain the general trends in the simulation results. It was found that maps with the correct proportion of forested and non-forested areas generally had simulated cumulative streamflow that matched closest to observed cumulative streamflow. Overall, the MODIS-derived land cover maps performed the best in terms of hydrological modeling using PRMS in the Yampa River Basin. However, the model was not found to be particularly sensitive to accurate land cover conditions. As a result, the scene and pixel accuracy results would not necessarily correlate with the model results.
Open Access
Assessment of Gullele Botanic Gardens conservation strategy in Addis Ababa, Ethiopia research from the Peace Corps Masters International Progam
(Colorado State University. Libraries, 2013) Reeder, Carl M., author; Laituri, Melinda, advisor; Evangelista, Paul, committee member; Daivs, Jessica, committee member; Sturtevant, Robert, committee member
Monitoring of current and future conditions is critical for a conservation area to quantify results and remain competitive against alternative land uses. This study aims to monitor and evaluate the objectives of the Gullele Botanic Gardens (GBG) in Addis Ababa, Ethiopia. The following report advances the understanding of existing understory and tree species in GBG and aims to uncover various attributes of the conservation forest. To provide a baseline data-set for future research and management practices, this report focused on species composition and carbon stock analysis of the area. Species-specific allometric equations to estimate above-ground biomass for Juniperus procera and Eucalyptus globulus are applied in this study to test the restoration strategy and strength of applied allometry to estimate carbon stock of the conservation area. The equations and carbon stock of the forest were evaluated with the following hypothesis: Removal of E. globulus of greater than 35cm DBH would impact the carbon storage (Mg ha-1) significantly as compared to the overall estimate. Conservative estimates found E. globulus accounted for 68% of the total carbon. Results of both the carbon stock and species composition analyses were used to delineate forest stands with a Geographic Information System. Ultimately, the strategy of GBG to restore native stand structure and understory species to the area will be advanced by the organization of forest stands delineated by this study.