LTER: Climate drivers, dynamics, and consequences of ecosystem state change in coastal barrier systems

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The Virginia Coast Reserve (VCR) Long Term Ecological Research project is dedicated to developing a predictive understanding of the dynamic landscapes of coastal barrier systems. Healthy coastal ecosystems are the first line of defense against sea-level rise and storms. Key components of those systems, i.e., barrier islands, intertidal marshes, and lagoons with seagrass, reduce erosion from storms, dampen wind and waves, and absorb flooding waters. Thus, coastal ecosystems protect coastal communities. In addition, these ecosystems provide benefits to society including support for fisheries, recreation, tourism, and sequestration of carbon. Sea-level rise, storms, and temperature extremes cause transitions among landscape components (e.g., changes between uplands to marsh, bare to seagrass-dominated lagoons). These transitions occur on time scales of years to many decades and influence the benefits of coastal ecosystems. The vast Virginia Coast Reserve is the greatest expanse of undeveloped coastline along the U.S. Atlantic seaboard. It provides a unique setting to understand the dynamics of long-term coastal change. This model system makes it possible to examine linkages among islands, lagoons, mudflats, marshes, and uplands. Such linkages can rarely be made in other regions where habitat fragmentation and human activities disrupt natural connections. Understanding these ecosystem transitions individually, and how changes propagate across the landscape through linked dynamics is a critical frontier in predicting the long-term response of coastal systems to significant environmental change. This project synthesizes long-term observations and experimental data with shorter-term studies to provide novel insights on ecosystem dynamics. These data promote the development and testing of mechanistic models that can predict landscape level change and its ecological consequences. With more than half the world's population living within 100 km of the coast, and even more depending on coastal resources, ecosystem changes in these regions have important consequences for coastal resilience. The VCR LTER program informs coastal management, restoration, and conservation to enhance coastal resilience to environmental changes through partnerships with management agencies and The Nature Conservancy. It contributes extensively to the training of Virginia teachers and the development of educational and outreach materials that reach national and international audiences. Finally, it supports the research training of undergraduates, graduate students and postdoctoral fellows. The program networks with other LTER sites along the Atlantic coast to provide a larger perspective on the eastern seaboard to managers, teachers, and students.VCR research advances this understanding through integrated studies of the ecological and physical (geomorphic, hydrologic) processes that drive ecosystem state change dynamics. Changes may be linear, or they may involve thresholds (tipping points) that lead to an abrupt, non-linear transition to a different ecological state. Addressing the complexity and interdependence of landscape components is critical to achieving a holistic understanding of coastal dynamics and will advance general theory on ecosystem state change and resilience. Research activities at VCR are organized around four related thematic questions: (1) Drivers and Patterns of Long-term Change: How have the distribution, spatial extent, and characteristics of ecosystems changed over time and how are these changes related to climate trends and variability? (2) Dynamics within Landscape Units: How do ecological and physical processes interact to maintain ecosystem states or facilitate transitions to new ones? (3) Dynamics between Landscape Units: How does connectivity influence ecosystem state change? (4) Ecological Consequences of State Change: What are the consequences of ecosystem state change for ecosystem function? VCR research focuses on carbon sequestration and habitat provisioning as two functions that are linked to important coastal ecosystem services. Collectively, this research will increase our predictive understanding of how coastal ecosystems and their functions respond to climate forcing at multiple spatial, temporal, and ecological scales.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.