Barrier islands may represent an underestimated sink for atmospheric carbon because they combine potential for high above-ground primary productivity (ANPP) with young, infertile soils capable of sequestering significant amounts of carbon. Ecosystem ANPP on many barrier islands of the Virginia Coast Reserve (VCR) has been further enhanced by the rapid expansion of woody shrubs. Compared to adjacent grasslands, shrubs in coastal systems combine high leaf area index with high photosynthetic rates.

Coastal marshes must increase elevation to maintain themselves in the face of sea-level rise. At the same time processes at their borders determine areal extent by fostering erosion or progradation at the seaward edge and transgression or stalling landward. Two major plant communities are recognized in many salt marshes: the high marsh and low marsh. At the mainland portion of the Virginia Coast Reserve we consider the high marsh to be dominated by Distichlis spicata and Spartina patens with prominent patches of Juncus roemerianus.

A pandemic wasting disease coupled with a destructive hurricane in the1930s, caused the local extinction of eelgrass (Zostera marina) in the Virginia coastal bays. Small patches of naturally-recruited seagrass were noticed in the late 1990s, prompting a large-scale restoration effort using seeds from nearby Chesapeake Bay. Restored meadows are currently thriving and expanding; however, there is a concern about the genetic structure of these meadows.

The barrier islands of the Virginia Coast Reserve LTER site provide an opportunity to study interisland variability of dune plant communities. Our research focused on the variation in biomass and diversity of communities among islands and dune positions. Grassy dunes of young, intermediate and old age were sampled on Smith, Hog, and Parramore Islands. Above- and belowground biomass were obtained from harvest plots and roots were extracted from cores. Data were also collected on depth to groundwater and total soil nitrogen.