Proposed Hydrogeomorphic Classification for Wetlands of the Mid-Atlantic Region, USA

Abstract

We propose a regional classification for wetlands of the Mid-Atlantic region, USA. It combines functional characteristics recognized by the hydrogeomorphic (HGM) approach with the established classification of the National Wetland Inventory (NWI). The HGM approach supplements the NWI classification by recognizing the importance of geomorphic setting, water sources, and flow dynamics that are key to functioning wetlands. Both NWI and HGM share at their highest levels the Marine, Estuarine, and Lacustrine classes. This classification departs from the NWI system by subdividing the Palustrine system into HGM classes of Slope, Depression, and Flat. Further, the Riverine class expands to include associated Palustrine wetlands, thus recognizing the interdependency between channel and floodplain. Deepwater habitats of NWI are not included because they differ functionally. Mid-Atlantic regional subclasses recognize two subclasses each for Flat, Slope, and Marine Tidal Fringe; three subclasses for Depression; four subclasses for Lacustrine Fringe and Estuarine Tidal Fringe, and five subclasses for Riverine. Taking a similar approach in other geographic regions will better characterize wetlands for assessment and restoration. This approach was applied successfully during a regional wetlands condition assessment. We encourage additional testing by others to confirm its utility in the region.

Geomorphic-centered classification of wetlands on the Qinghai-Tibet Plateau, Western China

“…Nevertheless, it is inapplicable to the plateau environment. Recently, Brooks et al (2011) adopted a hydrogeomorphic approach in classifying wetlands in the Mid-Atlantic region of the US. It recognizes the important role that geomorphic setting, water sources and flow dynamics play in the healthy functioning of wetlands.…”

Assessment of a judgment‐based hydrogeomorphic wetland classification using long‐term hydrologic data

“…Recent changes to the classification (Brooks et al, ; Cole et al, ) included the differentiation of slope types such that those wetlands at the toe of slopes are now recognized as a subclass distinct from upper slope wetlands. This was evident from the long‐term data but not from the short‐term data that informed the original classification and key (Cole et al, ).…”

Testing a rapid Floristic Quality Index on headwater wetlands in central Pennsylvania, USA

“…Of these seven subclasses, four are common to the Ridge and Valley: mainstem floodplains, headwater floodplains, riparian depressions, and slopes (Cole et al, 1997). A more recent classification for the MidAtlantic (Brooks et al, 2011) combines the latter three subclasses into a single system: riverine headwater complex because they often occur in a mosaic without distinguishable boundaries and are floristically similar (Chamberlain unpubl. data).…”