The Virginia Coast Reserve Long-Term Ecological Research Project

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Presenter/Primary Author: 
Karen McGlathery
Patricia Wiberg
John Porter

The Virginia Coast Reserve (VCR) is an extremely dynamic, heterogeneous coastal barrier landscape comprising mainland watersheds, tidal marshes, lagoons, and barrier islands. Our goal for the VCR LTER program is to develop a predictive understanding of the response of coastal barrier systems to long-term environmental changes in climate, sea level and land use, and to relate these to the ecological services the coastal barrier systems provide. We focus on how slow progressive environmental changes interact with short-term disturbances such as storms and species invasions to control the dynamics and biotic structure in the coastal barrier landscape.

The central hypothesis of the VCR LTER is that ecosystem dynamics and pattern on the landscape are controlled by the interaction between the vertical positions of the land, sea, and groundwater free surfaces, and the fluxes of organisms and materials across the landscape. Our approach to studying long-term change at the VCR LTER is to organize our studies across the landscape using a hypsometric framework. Changes in the relative vertical positions of the land, sea, and groundwater free surfaces give rise to ecosystem state changes. In the tidal marshes, the sea level intersects with the sloping land and groundwater. In the lagoons, the groundwater delivers nutrients from coastal watersheds and the land (lagoon bottom) and sea level together determine water depth, light availability and the tidally-driven exchange with the coastal ocean. On the barrier islands, the land and water table structure island vegetation and associated animal communities. Within this context, we believe that chronic drivers (climate, sea level, land use) and episodic disturbances (storms) cause ecological changes to occur non-linearly, with systematic progressive changes (succession) interrupted by abrupt transitions between ecosystem states (state change).