A STREAM HISTORY SURPRISE - REVEALING NOVEL STREAM ECOSYSTEMS IN MARYLAND'S URBAN COASTAL PLAIN USING CONVENTIONAL SOIL CORE DATA

Recent federal water regulatory actions, namely the Clean Water Rule and Chesapeake Bay TMDL, are changing what we seek to understand about urban streams, their histories, and their functional potential as restored or rehabilitated habitats. Shallow soil observations and diagrammatic pyramids have some scientific basis in determining the trajectory of degraded urban streams and how destructive sediment and nutrient feedback processes may be abated, however, these regulatory-driven processes frequently fail to adequately describe historic, or potential future repaired site characteristics.

Instead, in the Maryland coastal plain, we propose functional analyses and restoration goals based on historic soils and archaeological pedology. On each of two sites where this work was performed in 2010-2013, significant evidence of an untold and unknown site pedology was made evident to scientists evaluating the sites. One site, "Church Creek II," is a degraded urban freshwater stream, however, manual soil cores, supported by historic mapping, reveal that a century ago, it was a tidally inundated salt marsh, several feet lower in elevation. Another site "Broad Creek III," is a severely degraded urban freshwater stream. Mechanical coring, supported by mining records, demonstrated that the site was historically an upland sand dune, excavated via mining in the early 1900s, creating a depression and a water feature on the site.

These histories suggest several things, including the notion that many currently degraded urban streams are "novel ecosystems" with little pedological or ecological relationship to historic natural resources or communities that were historically present at the site. These exercises also demonstrate that regulatory attempts to require "in-kind replacement" of existing habitats may not be scientifically based, and are challengeable. Such efforts in many cases replace a "novel ecosystem" with a more stable version of that "novel ecosystem." For future consideration of ecological restoration sites, we recommend significant investigation into site soil histories as a basis for habitat restoration goal setting.