Paleoenvironmental Reconstruction and Landscape Interactions in the National Parks of Southwest Alaska
Project ID: J9W88030009
Federal Agency: National Park Service
Partner Institution: University of Alaska Anchorage
Fiscal Year: 2003
Initial Funding: $197,519
Total Funding: $197,519
Project Type: Research
Project Disciplines: Biological
National Park: Southwest Alaska Network Inventory & Monitoring
Principal Investigator: Heiser, Patricia
Agreement Technical Representative: Bennett, Alan
Abstract: A detailed investigation of the lake systems, including associated landforms and sediments, in the Southwest Alaska Network with the goal of providing a better understanding of the geologic origin and dynamic processes responsible for the formation and function of these important systems. Using paleoecological and paleoenvironmental methods, this research will help scientists and resource managers better understand long-term trends in both the biotic and physical limnology of these lakes and their effects on important resources like sockeye salmon. It will also provide insight into how climatic, oceanographic and geologic processes interact with these freshwater ecosystems. This approach will better enable us to fully understand how landscapes have evolved since deglaciation, how and when the current ecosystems became established, and how they might be vulnerable to change in the future. Finally, this study will help park researchers and managers understand how humans have influenced lake ecosystems and resources through both local and global scale activities. Major goals of the paleoenvironmental reconstruction study are to:
1. Determine the timing of deglaciation, and reconstruct extent and timing of major lake level changes and hydrologic changes in important stream systems.
2. Determine the timing and severity of volcanic ash fall events in the SWAN.
3. Reconstruct history of vegetation succession, changes, and ecosystem interactions since the last ice age by analyzing pollen found in sediment cores.
4. Determine, and differentiate between, multiple factors that could potentially influence the records of past changes in salmon abundance.
This research will help address questions such as:
1. What geomorphic, environmental, or climatic factors control changes in the formation, productivity, and access to major sockeye salmon systems?
2. Will some lakes show responses to one major, or several combined, external factors?
3. How will these factors help us interpret the record of ancient salmon abundance in terms of cause and effect? (e.g. Are changes in lake level, drainage systems, or stream gradients more important than climate or ocean productivity?)
4. What is the frequency of volcanic events, and how have they influenced terrestrial vegetation, aquatic productivity, and salmon abundance?
5. Does terrestrial ecologic succession and/or vegetation change influence lake productivity and/or salmon abundance?
This work will provide essential background data for a number of other research efforts including a SW Alaska Network wide salmon history project led by Bruce Finney of UAF. An understanding of landscape and hydrologic history is essential to the interpretation of lake sediment records of salmon abundance. Additionally, the study described here, and previous work leading to this proposal, will form an important component of an ongoing, collaborative, and successful investigation of the population structure and genetic diversity of Lake Clark sockeye salmon led by Dr. Carol Ann Woody of the USGS Alaska Science Center. Salmon biologists and geneticists recognize the important role of geologic history in the colonization and local adaptation that has shaped spawning populations of Lake Clark sockeye salmon. Finally ecological mapping efforts by NPS Biological Resources ecologists are strongly based on landscape type and environmental conditions. This work will lend an historical perspective, as well as a landscape-scale view of how ecosystems have evolved, changed, and responded to geologic and climatic drivers.