Wetland research can influence policy

Background/Question/Methods

An objective of ecological research is to have a positive influence on the way natural resources are managed.  The ability to influence policy with science depends on collaboration with the appropriate audience, identification of a relevant question, and awareness of the framework in which the policy is implemented.  Research that provided part of the technical basis for the compensatory mitigation guidance issued by the U.S. Army Corps of Engineers (COE) illustrates these principles.  The research was designed to fill a major gap in the science that supported the U.S. Environmental Protection Agency’s (EPA) responsibilities under the Clean Water Act (CWA).  Specifically, the Agency needed to know how mitigation decisions in an area added up to affect the ecological condition of the wetland resource.  EPA also needed information for tracking progress toward the national goal of “no net loss” in addition to changes in wetland area.  The type of mitigation studied employed wetland establishment, restoration and/or enhancement to compensate for permitted wetland losses.  Field data, topographic maps, wetland maps, and permit information were used to classify 96 wetlands, 47 naturally occurring (NOWs) and 49 mitigation wetlands (MWs) in the Portland, Oregon area, by the hydrogeomorphic (HGM) system.  The classification of MWs required development of new, atypical HGM classes to describe mismatches between site morphology and landscape setting:  depression-in-riverine-setting, depression-in-slope-setting, and in-stream-depression. 

Results/Conclusions

Most NOWs were riverine (53%) and slope (17%) wetlands, whereas most MWs were depressions-in-riverine-setting (33%) and in-stream-depressions (33%).  HGM classification and supporting ecological data showed that the regional and atypical HGM classes are distinct and that MWs and NOWs were different.  MWs are ostensibly built to provide functional replacement for wetlands destroyed by development.  However, the differences in HGM types between NOWS and MWs indicated that MWs were not fulfilling the goal and were concurrently changing and reducing the landscape diversity of wetlands and their associated functions.  These findings were cited by the National Research Council (NRC) in their recommendation to the COE and EPA to consider the hydrogeomorphic features of subject wetlands as part of a watershed approach during CWA Section 404 permit review.  Both the COE and EPA continue to respond to the NRC’s recommendations to improve the success of wetland restoration and mitigation projects.