The Great Lakes (GL) are a vital freshwater resource with chronic water quality problems. Climate-change-induced extreme events are expected to affect the region's ecosystems and ecosystem services, with impacts on social and economic well-being. Despite mounting evidence of the severity of these issues, knowledge is limited and fragmented about how the climate, ecological, and social systems interact as coupled systems. The re-eutrophication of Lake Erie illustrates the complex interactions among natural and human systems, and points to the challenge of managing this resource effectively and adaptively. In the GL region, agricultural production and land use change are major drivers of water quality, and extreme weather events can influence the choice of agricultural practices. For example, larger storm events can increase use of tile drains or prolonged drought can increase adoption of irrigation. Land use practices also interact with extreme weather events to impact water quality. For example, increasing intensity of spring storms and their timing relative to fertilizer application has been hypothesized to change the ratio of dissolved reactive phosphorus to total phosphorus in runoff, impacting Lake Erie phytoplankton communities. Through these and similar feedbacks, climate-change-induced extreme events may cause as yet unpredicted impacts to the GL ecological and socio-economic systems. These changes, in turn, might feedback on the region's climate, driving further system changes.
Intellectual Merit: This proposal asks: "What are the possible effects of climate-changed-induced extreme events on water quality and ecology in the Great Lakes system, and what management strategies will be effective in addressing these changes?" The complex, co-evolving human and natural systems in the GL region create the need for a paradigm shift in the study of water quality. Accordingly, they will address this question, with a focus on the climate-sensitive western basin of Lake Erie, through the lens of Sustainability Science, which provides a framework in which each sub-system can autonomously change through time while interacting with other sub-systems. In applying this framework, they will develop models, analysis, data, and information to better understand interactions among the physical, biological, social, and economic systems, and to explore and inform potential governance system responses to these changes. They will create new knowledge both within the individual components (physical climate, eco-hydrological, socio-economic) and through synthesis of these components. The physical climate component will investigate extreme-event precipitation formation and the role of land-use/lake/atmosphere feedbacks through a combination of climate and event-based simulations. The social and economic components will study the implications of climate-change-induced adaptations in human migration and agricultural production for spatial land use patterns and land markets. The eco-hydrological component will move beyond the traditional notion that freshwater eutrophication is driven by total phosphorus loads, and explore how the climate / extreme-event / land-use interactions enhance delivery of more biologically active phosphorus forms. To further understand GL water quality issues, the relative effects of phosphorus loading versus invasive species in the re-eutrophication will be examined. The governance component will innovate by gauging how integrated knowledge may change decision-makers' perceptions of available institutions and tools, and what they might need to design new ones. The components will inform one another through model-based interactions, and the outcomes of the modeling activities will be used to further understand opportunities and constraints in governance systems. By using the paradigm of sustainability science to propose a framework for the integrated study of water systems, the framework, methods, and many results will be transferable to other problem settings and locations.
Broader Impacts: Their results will advance the scientific understanding of coupled human-climate-water quality systems, and inform and influence decision-making in the Great Lakes region. They will promote training, teaching, and learning by integrating research into K-12 education through the Investigate the State (ITS) and Michigan Sea Grant (MSG) programs, and will broaden participation of underrepresented minorities through inquiry-based study at the Ypsilanti New Tech High School. Broad dissemination will also occur through publication of research results, and through creation of educational and professional development resources via the ITS and MSG programs. The eco-hydrological and socio-economic components will build on existing networks, and closely involve watershed councils and government agencies. They will train five graduate students and two postdoctoral scholars, with specific attention to mentoring postdoctoral scholars and training graduate students in an integrated interdisciplinary context.
