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Reference site selection for the National Wetland Condition Assessment: Integrating best professional judgement and objective selection criteria
Citation:
NESTLERODE, J., G. SERENBETZ, AND M. SCOZZAFAVA. Reference site selection for the National Wetland Condition Assessment: Integrating best professional judgement and objective selection criteria. Presented at 9th INTECOL International Wetlands conference, Orlando, FL, June 03 - 08, 2012.
Impact/Purpose:
The NWCA collected information from wetland habitats across the lower 48 states during Summer 2011. We present the process by which reference sites were selected and evaluated and used for comparison to probabilistically-based sampling sites during data analysis for the survey.
Description:
The National Wetlands Condition Assessment (NWCA), one of a series of environmental assessments being conducted by states, tribes, the U.S. Environmental Protection Agency, and other partners, surveyed over 900 wetland sites across the lower 48 states during Summer 2011. The NWCA is designed to assess ecological integrity at regional and national scales and identify and rank the stressors most commonly associated with poor conditions. As deviation from the reference condition may be used as a measure of the effect of stressors on the assessment area, the selection and evaluation of reference sites that represent the best attainable (or least disturbed) watershed condition, habitat structure, water quality and biological parameters are critical components of the NWCA assessment. Over 1100 handpicked candidate reference sites across six select coastal and inland wetland types were obtained from state, university, and other federal monitoring programs. These candidate reference sites were critically evaluated with a set of explicit criteria, using a combination of ground reconnaissance, aerial photography interpretation, and soil and vegetation maps, to yield 110 sites that will be used for comparison to probabilistically-based sampling sites during data analysis.