• Managing The National Wildlife Refuge System With Climate Change: The Interaction Of Policy, Perceptions, And Ecological Knowledge

      Magness, Dawn Robin (2009)
      The National Wildlife Refuge System (NWRS) is committed to conserving fish, wildlife, and plants for current and future generations of Americans. Given a rapidly changing climate, managers may employ various adaptation strategies to meet legislated mandates. I explore how ecological context, policy, perceptions and available ecological knowledge inform adaptation strategies. In Chapter 2, I develop an ecosystem vulnerability framework to better understand how climate change risk and ecosystem resilience interact to impact the NWRS. With GIS, I rank refuges based on historic temperature change, historic precipitation change, and sea-level rise risk. To index resilience, I rank refuges based on refuge size, landscape road density, and elevation range. Using this GIS analysis and the ecosystem vulnerability framework, I categorize the 527 refuges into four groups (refugia, ecosystem maintenance, facilitate transitions, and experiments in natural adaptation) that provide a necessary context for national, strategic adaptation planning. In Chapter 3, I survey 32% of NWRS biologists and managers to understand how policy and their perceptions of climate change influence adaptation choice. Currently, managers and biologists independently decide if climate change is natural or anthropogenic for wildlife management, and this conceptualization becomes important for deciding whether reactionary or anticipatory adaptation approaches are more appropriate. Although respondents considered practicability, they prefer historic condition. Respondents also prefer ecosystems and species adapt naturally. In a rapidly changing climate, natural adaptation may not be feasible without large-scale extinction. Nonetheless, many biologists and managers are uncomfortable with the alternative of manipulating ecosystems and species assemblages toward future conditions. Finally, understanding climate change impacts requires the analysis of complex ecological relationships over time and this complexity creates another barrier for implementing a national adaptation strategy. In Chapter 4, using a data-mining approach on data from scaled-down GCMs and an atypical monitoring approach, I build bioclimatic envelope models to show how the distributions of two passerines will potentially shift in response to climate change over the next 100 years on Kenai National Wildlife Refuge. In order to effectively manage species within the context of strategic adaptation planning, the NWRS must design future biological monitoring approaches with spatial modeling in mind.
    • Resilience Of A Deer Hunting System In Southeast Alaska: Integrating Social, Ecological, And Genetic Dimensions

      Brinkman, Todd J. (2009)
      I examined the interactions of key components of a hunting system of Sitka black-tailed deer (Odocoileus hemionus sitkensis) on Prince of Wales Island, Alaska to address concerns of subsistence hunters and to provide a new tool to more effectively monitor deer populations. To address hunter concerns, I documented local knowledge and perceptions of changes in harvest opportunities of deer over the last 50 years as a result of landscape change (e.g., logging, roads). To improve deer monitoring, I designed an efficient method to sample and survey deer pellets, tested the feasibility of identifying individual deer from fecal DNA, and used DNA-based mark and recapture techniques to estimate population trends of deer. I determined that intensive logging from 1950 into the 1990s provided better hunter access to deer and habitat that facilitated deer hunting. However, recent declines in logging activity and successional changes in logged forests have reduced access to deer and increased undesirable habitat for deer hunting. My findings suggested that using DNA from fecal pellets is an effective method for monitoring deer in southeast Alaska. My sampling protocol optimized encounter rates with pellet groups allowing feasible and efficient estimates of deer abundance. I estimated deer abundance with precision (+/-20%) each year in 3 distinct watersheds, and identified a 30% decline in the deer population between 2006-2008. My data suggested that 3 consecutive severe winters caused the decline. Further, I determined that managed forest harvested >30 years ago supported fewer deer relative to young-managed forest and unmanaged forest. I provided empirical data to support both the theory that changes in plant composition because of succession of logged forest may reduce habitat carrying capacity of deer over the long-term (i.e., decades), and that severity of winter weather may be the most significant force behind annual changes in deer population size in southeast Alaska. Adaptation at an individual and institutional level may be needed to build resilience into the hunting system as most (>90%) of logged forest in southeast Alaska transitions over the next couple decades into a successional stage that sustains fewer deer and deer hunting opportunities.