Forestry
http://hdl.handle.net/1773/4922
2024-03-19T01:10:47ZComparing, matching, detecting, and predicting drought-induced tree mortality in the Sierra Nevada, California
http://hdl.handle.net/1773/51181
Comparing, matching, detecting, and predicting drought-induced tree mortality in the Sierra Nevada, California
van Wagtendonk, Liz
In the last decade, technology and computing capabilities have evolved to allow the detection of individual trees with remote sensing. This innovation is invaluable to researchers and managers who seek precision methods to measure forest condition in a rapidly changing world. To apply remotely sensed methods to evaluate population trends, a framework is required to enable the application of these methods to detect and predict the trends of tree populations. Such a framework requires assessing the uncertainty and bias associated with applying remotely sensed methods to reflect the population trends of individual trees. The goal of my dissertation was to establish a framework for defining the population trends of remotely sensed trees in the context of an extensive tree mortality event. Further, I endeavored to measure the uncertainty and bias associated with applying remotely sensed trees to represent drought-induced mortality trends.
Thesis (Ph.D.)--University of Washington, 2023
Climate impacts and adaptation in the Dungeness crab fishery: a social-ecological systems perspective
http://hdl.handle.net/1773/51182
Climate impacts and adaptation in the Dungeness crab fishery: a social-ecological systems perspective
Fisher, Mary
Dungeness crab (Metacarcinus magister, or Cancer magister Dana) is an iconic species on the U.S. West Coast, where it supports one of the largest and most valuable commercial fisheries, as well as culturally important recreational and subsistence harvests. Yet over the past decade, Dungeness crab fisheries have faced numerous closures from the effects of long-term ocean change and associated extreme events. My research examined climate change impacts and adaptation in the Dungeness crab fishery by exploring the changing inter-relationships within and between coupled human and ecological communities. I first considered trophic-mediated climate risk to juvenile Dungeness crab, demonstrating the value of molecular diet analysis (“dDNA”) in understanding risk to, and potential adaptability of, marine species facing disrupted predator-prey relationships. I then examined Dungeness crab fishers’ adaptation to an unprecedented, coastwide harmful algal bloom in 2015, which led to the most extensive closures the California commercial fishery has ever seen. I quantified how fishers’ use of certain coping and adaptative strategies varied by vessel size class and geographic region; I then asked how these strategies may have affected the distribution of climate impacts at the time of the closures, and fishing communities’ vulnerability to secondary shocks. Finally, I collaboratively summarized Dungeness crab fishery dynamics in a social-ecological qualitative network model. I then used this model to explore how planned climate adaptation can lead to unintended consequences for fishers’ well-being, as it interacts with the effects of harmful algal blooms and fishery dynamics. I specifically considered climate adaptation strategies identified during regional, participatory scenario planning initiatives. Together, these inter- and multi-disciplinary research projects offer an integrated view of climate change in the Dungeness crab fishery, and illustrate the role of adaptation in how climate impacts manifest in marine fisheries.
Thesis (Ph.D.)--University of Washington, 2023
Investigating patterns in stream temperature and restorable alluvial water storage for climate resilience of freshwater habitat for salmon and trout
http://hdl.handle.net/1773/51180
Investigating patterns in stream temperature and restorable alluvial water storage for climate resilience of freshwater habitat for salmon and trout
Duncan, Casey M.
As climate change shifts the availability of habitat for aquatic species, watershed management must focus on the conservation and restoration of cold-water habitats for species such as salmon and trout that require cold water. Management actions that focus on restoring hydrologic processes can be used to adapt to climate impacts by re-establishing groundwater exchange and cold-water habitats. The formation of cold-water habitat can be promoted by reconnecting rivers to their adjacent floodplains and restoring alluvial water storage. In this study, I applied a systematic method for identifying spatial patterns in stream temperature and prioritizing restoration locations for climate adaptation. I made use of available data derived from airborne thermal infrared imagery to identify spatial patterns of stream temperature in the Teanaway River watershed in Washington, USA and compared these patterns to modeled predictions of restorable alluvial water storage. By investigating patterns in continuous stream temperature at a 1-km scale in the watershed, I provide information that can be used to locate where restoration may address both water storage and water temperature and improve climate resilience of freshwater habitat for cold water-dependent species, such as salmon and trout. This work contributes to scientific understanding of how spatial analyses can be used to evaluate climate resilience of freshwater habitat and prioritize locations for ecosystem restoration.
Thesis (Master's)--University of Washington, 2023
Exploring Complexity, Uncertainty, and Risk in Avian Reintroduction Decisions Through Structured Decision Making
http://hdl.handle.net/1773/51179
Exploring Complexity, Uncertainty, and Risk in Avian Reintroduction Decisions Through Structured Decision Making
Sipe, Hannah Anderson
Avian species reintroductions are a vital tool for mitigating threats and avoiding extinction. However, the decisions required to reintroduce species are overwhelmingly complex. The complexity arises from many interacting factors, including challenges in identifying the specific decision to be made or the alternatives available to the decision maker, limited information about species biology or ecology, unknown effectiveness of management actions, risk of species loss, limited resources, multiple management objectives, multiple distinct management authorities, and lengthy time scales over which actions must be taken. Decision analysis, or structured decision making (SDM), offers a framework for gaining traction on complex decision problems. An SDM process can provide decision makers with a clear view of the decision problem and a clearly defensible justification for the decision. The research I present here explores the use of SDM for informing avian reintroduction decisions through the application of SDM to three case studies: vertebrate (primarily avian) restoration to the island of Guam, management of a reintroduced population of Hihi (Stitchbird; Notiomystis cincta) in New Zealand, and Streaked Horned Lark (SHLA; Eremophila alpestris strigata) reintroductions in Washington State. First, I facilitated a collaborative decision process to determine the problem structure of a complex decision problem regarding vertebrate species restoration in Guam (Chapter 2). Then, using the products of Chapter 2, I developed quantitative models to predict outcomes of alternative restoration strategies for two of Guam’s vertebrate species (Chapter 3). Second, I employed SDM to address the challenge of a struggling reintroduced population of Hihi in New Zealand through the exploration of competing hypotheses about the cause of flat to slightly declining population trends (Chapter 4). Third, I used SDM to develop and evaluate reintroduction strategies for SHLA in Washington State (Chapter 5). Together, these case studies demonstrate how values-based decisions can be made by using all available scientific information to improve the likelihood of successful reintroduction outcomes. Further, my research demonstrates that uncertainty and complexity need not prohibit forward progress toward reaching management objectives.
Thesis (Ph.D.)--University of Washington, 2023