In addition to supporting different needs in different urban contexts, wetlands vary in their intrinsic nature. There are different hydrogeomorphic types of wetlands (Brinson, 1988). Wetlands in riverine settings differ from depressional wetlands or spring fens away from riparian areas in their hydrologic characteristics, size, and potential utility to serve specific functions. Effective planning to include and maintain wetlands in the urban setting requires understanding the greater suitability of some wetland types for certain functions, potential thresholds for negative interactions among incompatible functions, and the greater vulnerability of some wetlands to suffer impairment from overloads of water, nutrients or toxics. A landscape approach to wetland planning, conservation and restoration (Bedford and Preston, 1988; Whigham et al., 1988; Kentula,1997; Kershner, 1997) is as important in urban areas as in more natural settings.

There is a need to better understand the multiple functions people expect wetlands to serve in urban areas, and in particular, to explore thresholds for given wetland functions beyond which their functionality for other goals may be impaired. A quantitative approach to the modeling of hydrologic and nutrient inputs is a critical starting point in understanding sources of water to wetlands and in quantifying the needs of the city for wetlands to serve as sites for storm water detention, water storage, and sediment and nutrient removal. In addition, understanding wetland hydrology and levels of loadings is a starting point for studies to determine the effects of nutrients and hydrology on wetland vegetation and functioning of wetlands as wildlife habitat. Finally, an understanding of social drivers, rather than more scientific data, may be the most critical information needed to assist in ecosystem management, particularly in facilitation of effective human decision making (Miller, 1985).
An Interdisciplinary Solution

Our interdisciplinary team of scientists at Oregon State University proposes to study how human social systems may assist both in preserving and restoring urban wetlands and how best to sustain the ability of wetlands to perform multiple functions in an urban setting.

· To build an interdisciplinary team for investigation of interactions among various functions desired from urban wetlands in the Portland area, and collaborative relationships with interdisciplinary teams from other regions (Midwest and eastern U.S.) interested in exploring similar issues for urban wetlands in their region.

· To develop partnerships with planners and agencies in the city of Portland, Oregon that will lead to improved understanding of the needs and expectations of the city agencies for these wetlands, and hypotheses about the characteristics of communities that may lead to conservation and restoration of wetlands in those communities.

· To involve graduate students and international students in active participation on interdisciplinary teams and educate them in methods and strategies for conducting interdisciplinary research.

· To assemble existing data sets and information that will help in understanding the social context of urban wetlands in the Portland area, as well as for modeling water and nutrient inputs and outputs, and investigating vegetation response to hydrologic regime and nutrient loading in these wetlands.

· To discern data needs, locate appropriate study sites, and develop a detailed proposal for submission to a funding agency in 2002 for a broad, cross-regional interdisciplinary study to explore thresholds of functionality for urban wetlands and how best to design urban wetlands and green spaces to sustain the multiple functions people expect wetlands to perform.