INVESTIGATION OF IMPACTS OF SEA-LEVEL RISE, STORM SURGE AND CLIMATE CHANGE ON MARITIME FORESTS ADJACENT TO CHINCOTEAGUE BAY, VIRGINIA USING DENDROECOLOGY TREE RING ANALYSIS

Coastal environments are susceptible to the impacts of climate change, sea-level rise, and storm surge impacts. In areas close to sea-level, healthy freshwater lenses displace the saltwater that would otherwise infiltrate into maritime forest soils. Droughts and intense and frequent storm surges have the capacity to allow salinization of forest soils leading to impaired tree growth and/or even death. This study uses dendroecologic methods to investigate tree growth histories to see how low-lying coastal forests of the Eastern Shore of Virginia are responding to the impacts of climate change and salt water intrusion.

This research focuses on a site on the mainland shore of Chincoteague Bay, Virginia near Powell’s Creek. Three parallel transects beginning at the shoreline and extending backward away from the coast were sampled using an increment borer. Each transect thus fronted directly on the shoreline of Chincoteague Bay and were susceptible to intense storm surge and saltwater intrusion. At this location, multiple Loblolly Pine, and Eastern Red Cedar trees growing ~1.0m above sea-level have been analyzed, and soil samples taken to assess soil pH patterns. Tree-cores were scanned and uploaded to Image J software to make measurements of tree ring widths and perform statistical analysis.

Although analyses are ongoing, all trees demonstrate similar trends in tree ring growth patterns. Narrower annular growth in tree rings are assumed to have been formed in drier or more stressed years, and years with thicker annular growth are assumed to have been wetter. Soil pH shows a definite trend with more acidic freshwater signatures inland, and higher soil pH values were measured by the shoreline suggesting the influence of marine water is more pronounced. Another observation made in preliminary evaluation is that the tree cores obtained closest to the beach show evidence of thinner tree rings overall (relatively more stressed), most likely due to salt water intrusion or decreased vitality of the freshwater lens. In addition, trees closest to the shoreline also appear to be impacted by higher densities of Pine Bark Beetle burrow damage. It is likely that the trees, which are already stressed, are much more susceptible to beetle infestation and are unable to recover adequately.