Prehistoric habitat stability and post-settlement habitat change in a Chesapeake Bay freshwater tidal wetland, USA

Analyses of fossil seeds and pollen grains preserved in seven sediment cores and borings were combined with historical land-use records to reconstruct an 1800-yr history of Otter Point Creek (OPC), a freshwater tidal deltaic wetland in the upper Chesapeake Bay. The objectives of the study were to document the role of natural and anthropogenic disturbance on habitat development at different sites within the wetland. Fossil seeds revealed a 1500-yr period (AD 230 to 1700) of subtidal habitat stability characterized by the aquatic macrophytes Zannichellia palustris, Najas gracillima, N guadalupensis, Elodea canadensis and Vallisneria americana. Natural disturbance had little or no impact on the estuarine habitat during this time. By the early 1700s, forest clearance for agriculture and lumber during European settlement led to higher erosion rates in the watershed. This led to rapid sediment efflux and broad habitat changes along a hydrologic gradient within the estuary. The aquatic macrophytes disappeared wh...