Integrating Biological, Physical, and Landscape Indicators for Wetlands, Streams, and Riparian Areas of the Mid-Atlantic Region

Robert P. Brooks 1, Denice Heller Wardrop 1, Joseph A. Bishop 1, Jennifer M. Rubbo 1, Susan E. Laubscher 1, Angela M. Conklin 1, Melinda M. Farr 1, Sarah J. Miller 1, and Timothy J. O'Connell 2.

1. Penn State Cooperative Wetlands Center, Department of Geography, 302 Walker Building, Pennsylvania State University, University Park, PA 16802 USA
2. Department of Zoology, 430 Life Sciences West, Oklahoma State University, Stillwater, OK 74078 USA

We compare correspondence across a set of biological, physical, and landscape indicators building on multiple approaches for assessing the condition of aquatic ecosystems, especially wetland, stream, and riparian components. By using this approach, we are trying to encourage the development of indicators of ecological structure and function, and to facilitate their holistic application. Our intent is to erase the boundaries among assessment approaches, so that the derived information can be applied across waters in an integrated manner. The Penn State Cooperative Wetlands Center is developing and testing a series of methods for assessing wetland, stream, and riparian condition which combine elements of hydrogeomorphic (HGM) functional modeling of wetlands, indices of biological integrity (IBI) for vascular plants, aquatic macroinvertebrates, amphibians, and birds, and GIS spatial analysis of landscape patterns. We conducted our comparisons in multiple ecoregions to illustrate selected aspects of the approach. HGM models and GIS analyses appear to be most reliable for the physical and landscape aspects of condition assessment, whereas IBIs address biotic responses to disturbance, whether the target habitat is aquatic or terrestrial. When comparing the responses of these indicators along a standard human disturbance gradient ranging from reference sites with the best attainable conditions to severely disturbed sites, we find remarkably close agreement within a habitat type, and reasonable correspondence among habitat types. To facilitate cross-method comparisons and integration, we propose that a standard, consistent scoring scale of 0.0-1.0 be used for each attribute. Striving to integrate assessments across waters will prove beneficial to managers.