ECOHYDROLOGICAL LINKAGES OF EASTERN SHORE MARYLAND COASTAL MARSHES: A TWO PART ASSESSMENT ON THE CONDITIONS OF PARALLEL DITCHED MARSHES

Ditch plugging is a low-impact method of restoring marshes but its effects on hydrological regime and ecosystem services has not been widely determined. The goal of this project was to assess ecohydrological processes operating in ditched drained marshes as well as the effects of ditch-plugging on Atlantic Coast and Chesapeake Bay marsh ecosystems. The main objectives of the study were to identify and compare pre- and post-plugging characteristics; determine restoration ecological effects; and identify site variables that could be used to predict the success of future ditch-plugging restoration projects. Three paired marsh systems of ditched and unditched marshes were used in this study. The paired sites were selected to be in the same general marsh area where topography, vegetation, and tidal patterns were assumed similar yet spatially separate. Data collection included hydrological and ecological properties such as ditch intensity, water quality, water table fluctuations and interaction with surfacewater, salinity profiles, and vegetation composition. Identification of hydrological to ecological linkages were determined before and after restoration. It was hypothesized that the hydrological pathways of sheet flow and infiltration would be dominant at the unditched sites whereas shallow lateral subsurface and conduit flow within ditches would be dominant in the ditched sites. It was hypothesized that the distribution of plant communities and soil characteristics would be correlated with geomorphologic and hydrologic conditions. Comparing the presence or absence of trends with hydrological and ecological parameters within pairs of unditched versus ditched, ditched versus restored, and unditched versus restored would be developed. This will result in quantifying spatial and temporal land use parameters to determine the impact of ditching and restoration within the ecosystem.