• Assessment of LiDAR and spectral techniques for high-resolution mapping of permafrost on the Yukon-Kuskokwim Delta, Alaska

      Whitley, Matthew Allen; Maio, Christopher V.; Frost, Gerald V.; Jorgenson, M. Torre (2017-05)
      The Yukon-Kuskokwim Delta (YKD) is one of the largest and most ecologically productive coastal wetland regions in the pan-Arctic. Formed by the Yukon and Kuskokwim Rivers flowing into the Bering Sea, nearly 130,000 square kilometers of delta support 23,000 Alaskan Natives living subsistence lifestyles. Permafrost on the outer delta commonly occurs on the abandoned floodplain deposits. Ground ice in the soil raises surface elevations on the order of 1-2 meters, creating plateaus on the landscape. Better drainage on the plateaus supports distinct Sphagnum-rich vegetation, which in turn protects the permafrost from rising air temperatures with low thermal conductivity during the summer. This ecosystem-protected permafrost is thus vulnerable to disturbances from rising air temperatures, vegetation mortality, and inland storm surges, which have been known to flood up to 37 km inland. This thesis assesses several novel techniques to map permafrost distribution at high-resolution on the YKD. Accurate baseline maps of permafrost extent are critical for a variety of applications, including long-term monitoring. As air and ground temperatures rise across the Arctic, monitoring landscape change is important for understanding permafrost degradation processes (e.g. thermokarst) and greenhouse gas dynamics from the local to global scales. This thesis separately explored the value of Light Detection And Ranging (LiDAR) and spectral datasets as tools to map permafrost at a high spatial resolution. Furthermore, this thesis sought to automate these processes, with the vision of high-resolution mapping over large spatial extents. Fieldwork was conducted in July 2016 to both parameterize and then validate the mapping efforts. The LiDAR mapping extent assessed a 135 km² area (~15% permafrost cover), and the spectral mapping extent assessed an 8 km² area (~20% permafrost cover). For the LiDAR dataset, the use of a simple elevation threshold informed by field ground truth values provided a permafrost map with 94.9% accuracy. This simple approach was possible because of the extremely flat terrain. For the spectral datasets, an ad-hoc masking technique was developed using a combination of texture analysis, principal component analysis, and morphological filtering. Two contrasting workflows were evaluated with fully-automated and semi-automated methods with mixed results. The highest mapping accuracy was 89.4% and the lowest was 79.1%, though the error of omission in mapping the permafrost remained high (7.02 - 59.7%) for most analyses. The spectral mapping algorithms did not replicate well across different high-resolution images, raising questions about the viability of using spectral methods alone to track thermokarst and landscape change over time. However, incorporating the spectral methods explored in this analysis with other datasets (e.g. LiDAR) has the potential to increase mapping accuracies. Both the methods and the results of this thesis enhance permafrost mapping efforts on the YKD, and provide a good first step to monitoring landscape change in the region.
    • Ecological development of a management plan for reindeer (Rangifer tarandus) on St. George Island, Alaska

      St. Martin, Michelle L. (2012-12)
      Management of an herbivore production system requires a working knowledge of the components and processes of the targeted grazing system. Land owners and stakeholders wish to develop a management plan for reindeer on St. George Island, Alaska. The foci of this study were to determine seasonal diet composition (including forage preference); evaluate nutritional content of Angelica lucid, a potential alternative winter forage; estimate lichen biomass; and estimate reindeer abundance, annual production, and sustainable stocking density. Lichens were the preferred reindeer forage throughout the year, however significant seasonal dietary shifts occurred across the seasons. Fortis and grasses were consumed in significantly greater proportion in spring and summer diets, sedges greater in the fall diets, and mosses greater in the winter diets. Angelica lucida was found in reindeer diets throughout the year. The nutritional profile and available biomass suggest this species may serve as an important forage for growth and maintenance of the reindeer. Both the reindeer population and calf:cow ratio increased from 2007 (290 individuals; 48:100 ratio) to 2008 (320 individuals; 57:100 ratio). The estimated total lichen biomass for the island was ~ 5.4 million kg dry matter which could support a population of 217 reindeer or 2.4 reindeer/ km².
    • Multiresolution digital soil mapping of permafrost soils using a random forest classifier: an investigation along the Dalton Highway corridor, Alaska

      Paul, Joshua D.; Ping, Chien-Lu; Prakash, Anupma; Rossello, Jordi Cristobal; Libohova, Zamir (2018-12)
      In order to complete soil inventories in the remote permafrost zones of Alaska, there is a need to develop efficient digital soil mapping tools that can be applied over large areas using a minimum of ground truth data. This investigation first used a random forest classifier to test combinations of environmental input data at multiple resolutions (10m, 30m, and 100m). Five tiers of soil taxonomic units were predicted: Order, Suborder, Great Group, "Series Concept", and Particle Size Class. Model outputs are compared quantitatively via estimated out-of-bag accuracy, and qualitatively via visual inspection by soil scientists. Estimated out-of-bag accuracy ranged from ~45% to ~75%, with results improving when fewer classes were modeled. Model runs at 10m and 30m resolution performed comparably, with 100m resolution performing ~5-10% worse in most cases. Increasing the number of trees used, including categorical environmental input data (e.g. landforms), and replacement of environmental covariates with principal component analysis (PCA) bands did not significantly improve model performance. The random forest classifier was then used in a digital soil mapping pilot study along the Dalton Highway in northern Alaska. Parameters suggested in the initial study were used to predict multiple soil taxonomic classes from a basic collection of environmental covariates generated using high resolution (10m) satellite images and sparsely sampled pedon data. Covariates included maximum curvature, multiresolution valley bottom flatness, normalized height, potential incoming solar radiation, slope, terrain ruggedness index, and modified soil and vegetation index. Five tiers of soil taxonomic units were predicted: Order, Suborder, Great Group, "Series Concept", and Particle Size Class. Model outputs are compared quantitatively via estimated out-of-bag accuracy. Estimated out-of-bag accuracy ranged from ~45% to ~75%, with results improving when fewer classes were modeled. We suggest future research into optimized sampling to ensure an adequate distribution of samples across the feature space, and the incorporation of expert knowledge into accuracy assessments. Overall, digital soil mapping with random forest classifiers appears to be a promising method for completing the soil survey of Alaska.
    • Public use of local foods in the Tanana Valley: understandings of producers and low-income community members

      Garcia, Rachel Aleksandra (2012-08)
      This thesis explores factors that affect local food use in the Tanana Valley region of Alaska. Alaskan public discourses increasingly link local food production to a more sustainable and secure state and community food supply. However, current local food system development in the United States is marked by signs of socially unequal distribution of the benefits of local food. In Spring 2011, semi - structured interviews and focus groups were conducted with agricultural producers and community members affiliated with the Special Supplemental Nutrition Program for Women, Infants and Children (WIC), and the Farmers' Market Nutrition Program (FMNP). Results show that local food use is complex and tied to livelihood and daily concerns of both producers and consumers. Producers highlighted challenges in food production, and characterized public use of local foods as limited by insufficient production. WIC employees and FMNP recipients viewed convenience and cost as important determinants of local food use. This exploratory study contributes to a more complex understanding of the local food system in the Tanana Valley through close examination of the perceptions and life experiences of human actors in this food system.
    • Social dimensions of invasive plant management: an Alaska case study

      Callear, Tara L.; Fix, Pete; Brinkman, Todd; Graziano, Gino (2018-05)
      Uncertainty pervades attempts to identify an efficient management response to the threat of invasive plants. Sources of uncertainty include the paucity of data, measurement errors, variable invasiveness, and unpredictable impacts of the control methods. Rather than relying on this uncertain evidence from the natural sciences, land managers are taking a more participatory approach to invasive plant management to help alleviate risk and share the responsibility of implementation of proactive control and eradication strategies. This research is intended to contribute to this process of social learning by revealing the beliefs that determine stakeholder management preferences in a case study involving an infestation of Vicia cracca (bird vetch) affecting public lands, north of the Arctic Circle, along the Dalton Highway in Alaska. Possible encroachment of this "highly invasive" species upon vulnerable areas of high conservation significance in this rapidly changing, boreal-arctic system has motivated some stakeholders to advocate an aggressive, early response aimed at eradication using herbicides. This case study applies social-psychological theory in the study of the interactions between human behavior and human outcomes. Interior Alaska stakeholders were engaged in a survey to measure support for a scenario involving the use of herbicides to control the highly-invasive species, Vicia cracca (bird vetch), which has spread north along a road corridor north of the Arctic Circle. Respondents were asked a series of questions about the "likelihood" and "acceptability" of the possible outcomes. The survey results aligned with the expectation that attitudes predict management preference, however the beliefs that influence these attitudes were more complicated than expected. The results address the feedbacks anticipated between the human outcomes and human behavior in the social template within the broader system context that are critical to management success. The purpose is to utilize the results of this specific case study to facilitate the development of ongoing research questions that are generalizable to other affected boreal-arctic ecosystems, regionally and globally.
    • Spatial and temporal trends in vegetation index in the Bonanza Creek Experimental Forest

      Baird, Rebecca A. (2011-08)
      Climate has warmed substantially in boreal Alaska since the mid-1970s. The direct effects of rising temperatures on sub-Arctic ecosystems are already being observed in the form of drought stress, increased fire frequency and severity, and increased frequency and severity of herbivorous insect outbreaks. These effects of climate change are having a direct impact on the vegetation of the boreal forest and leading to a decreased remotely sensed normalized difference vegetation index (NDVI), which is an effective proxy for landscape-scale plant productivity and photosynthesis. Therefore, NDVI is a useful tool to examine landscape-scale changes in vegetation over time, especially in the context of known climate change. The overarching goal of my research was to assess the change in vegetation index at multiple scales over a period of 23 years at Bonanza Creek Experimental Forest. I used a combination of remote sensing and field sampling to examine trends in NDVI across landscape units, topographic classes, and plant communities. My project consists of two main parts: 1) Create a floristically-based landcover classification through field sampling and incorporating the field data into a map using satellite imagery and 2) Examine trends in the vegetation index using 11 Landsat TM and ETM+ images from 1986-2009. By using Landsat imagery and doing a landcover classification of my study area I was able define trends in NDVI to specific landscape units, topographic classes, and plant communities in the study area.
    • Spatial resilience and the incorporation of traditional ecological knowledge in mapping Sitka herring

      Shewmake, James W. II; Greenberg, Josh; Verbyla, Dave; Holen, Davin (2013-05)
      This project assesses the utility of Traditional Ecological Knowledge (TEK) in conducting research on herring stocks within Sitka Sound. By considering ethnographic data of the marine environment it is possible to identify key spatial attributes associated with the resource. This information was used to construct a social-ecological systems model (SES) for analysis within a spatial resilience framework. From this SES model, resilience surrogates were identified to analyze effort and success within the fishery. These indicators provided valuable insight into how subsistence users relate to the marine environment when they participate in the harvesting of herring spawn. To collect TEK data, the researcher, employed as a graduate intern with the Division of Subsistence, Alaska Department of Fish and Game (ADF & G) worked cooperatively with the Sitka Tribe of Alaska (STA). TEK data was used to identify marine habitat types, subsistence harvest locations (mapping), customary and traditional practices, and changing trends in accessibility to the resource. This information was supplemented with quantitative data including spatial habitat mapping and herring spawn distribution. A Geographic Information System (GIS) was used to display, analyze, and understand these variables and their measured outcomes to construct the SES model.
    • A study of soil topo-sequences in the Steese and White Mountains of Alaska

      Geisler, Eric S.; Ping, Chien-Lu; Juday, Glen; Swanson, David (2018-08)
      The Steese Mountains of Alaska present a complex landscape on which to study soil formation and characteristics in relation to topographic position. The White and Steese Mountains of Alaska are located approximately 70 to 220 km northeast of Fairbanks. Ten toposequences with 3 or 4 sites each were described in the field, sampled, and analyzed in the laboratory in order to determine the relationship between soil morphology and soil-forming factors. Permafrost is discontinuous within the study area and vegetation ranges from tundra on summits to boreal stands of resin birch, quaking aspen, black spruce and white spruce along the lower elevations. There have been many wildfires over time that may have altered the soils and affected the vegetation successional patterns. The processes through which various soil patterns have formed and the unique characteristics of the soils are described here based on field data obtained from both burned and unburned sites. The analysis includes biophysical settings, parent material, texture and nutrient concentrations. Organic horizons were common on most of the transects and play a key role in the depth of the active layer where they exist. Nutrient concentrations are also closely tied to the presence and depth of the organic horizons. Some patterns described in other areas of the boreal region were not observed in this study. There were some soil properties that are not readily described under the current taxonomy protocols which are suggested to be added in a future revision of Soil Taxonomy.
    • Temporal and spatial variation of broadleaf forest flammability in boreal Alaska

      Wehmas, Maija I.; Verbyla, David; Mann, Daniel; Hollingsworth, Teresea (2018-08)
      The boreal forest is a carbon reservoir containing roughly 40% of the world's reactive soil carbon, which is mainly cycled by wildland fires. Climate warming in boreal Alaska has changed the wildfire regime such that an increase in broadleaf forest relative to conifer forest is likely, which may reduce landscape flammability. However, the current and future flammability of broadleaf forest in a warming climate is not well understood. We used pre-fire and post-fire geospatial data to investigate the flammability of upland boreal forest patches in Interior Alaska in relation to summer weather conditions. Our objectives were to assess burning of broadleaf forest patches during "Normal" vs. "Large Fire Years", by week within a fire season, and by topographic position. Using 30-meter land-cover and fire-severity grids, we estimated the flammability of upland broadleaf forest patches during Large and Normal Fire Years. We then tested for topographic effects using a solar radiation index to eliminate potential deviations within the vegetation. Finally, Moderate Resolution Imaging Spectroradiometer (MODIS) hotspots were used to track the spatial extent of burns during the fire season by examining the periods of fire activity and intensity. Flammability of broadleaf forest patches varied both in time and space. Even during Normal Fire Years, broadleaf forest patches exhibited substantial flammability, with a mean of over 50% patch area burned. Patch flammability was significantly higher during Large Fire Years. Burning of broadleaf patches varied with topographic position and correlated with potential insolation. Broadleaf forest patches burned most frequently in late June-early July. Contrary to "conventional wisdom", broadleaf forest patches in boreal Alaska are susceptible to burning even during Normal Fire Years. With climate warming, the flammability of broadleaf forest is likely to increase due to more extreme fire weather events. Thus, although the frequency of broadleaf forest patches on the landscape is likely to increase with more frequent and severe wildfires, their effectiveness as a fire break may decrease in the future.
    • Why did Alaska eliminate the Alaska Coastal Management Program?

      Wilson, Ryan M.; Todd, Susan; O'Donoghue, Brian P.; Speight, Jeremy S. (2018-05)
      In 1972, the federal government passed the Coastal Zone Management Act. The federal government recognized that there is a national interest in effective management of the nation's coasts. The act created a program that made it possible for states to collaborate with the federal government to manage the nation's coastal areas and resources. In July of 2011, after thirty-two years of active participation in the program, Alaska became the only eligible state or territory to choose to no longer take part in the program. This action significantly affected Alaska's ability to manage the state's coastline and resources. This research is a qualitative case study that documents the events leading up to the establishment of the Alaska Coastal Management Program, its implementation, its elimination, and the initiative regarding its possible reinstatement. The research evaluates the current form of Alaska's coastal management practices to determine if it meets Elinor Ostrom's design principles for effective common property resource management, as well as theories on decentralization/devolution, polycentric governance, and adaptability and resilience. The research concludes that Alaska's choice to eliminate the Alaska Coastal Management Program was influenced by the interests of natural resource extraction agencies and a consequence of divisive party politics. The research finds that the effect of eliminating the Alaska Coastal Management Program was that the State of Alaska took a significant step away from what science recommends as prudent ways to manage common property resources.