Floristic Quality Assessment for Minnesota Wetlands

Wetlands are a prevalent feature across the Minnesota landscape, occupying an estimated 9.3 million acres (www.dnr.state.mn.us/wetlands/index.html). This area, however, represents approximately only half of the pre-European settlement wetland acreage in the state (Anderson and Craig 1984). The majority of the historical wetland losses were due to draining and filling activities undertaken to increase the economic productivity of the land. In addition to the loss of wetland acres, many remaining wetlands have been negatively impacted by anthropogenic stressors (human caused external forcing factors that cause change to wetlands; Rapport et al. 1985, Detenbeck et al. 1999) resulting in a degradation of wetland quality. Examples of anthropogenic stressors to wetlands include hydrologic alterations (Wilcox 1995), nutrient enrichment (Kadlec and Bevis 1990), and competition or displacement from exotic invasive species (Galatowitsch et al. 1999). Recognition of the ecological importance of wetlands and loss of wetland acreage resulted in the no net loss policy initiated in the early 1990s at both the state and federal level. No net loss is enacted through a variety of mechanisms, such as Section 404 of the Federal Clean Water Act (CWA) and Minnesota's Wetland Conservation Act (WCA), that regulate drain and fill activities. On agricultural lands, no net loss is also implemented through the 'swampbuster' provisions in the Food Security Act (i.e., Federal Farm Bill) that deny federal crop subsidies to landowners who drain or fill otherwise exempted wetlands on working lands. While no net loss is often referred to only in terms of wetland quantity (acres), the policy also clearly includes wetland quality. For example, a goal of the WCA is to "achieve no net loss in the quantity, quality, and biological diversity of Minnesota's existing wetlands" (Minn. S. 103A 201). The WCA further establishes the goal to increase the quantity, quality, and biological diversity of Minnesota's wetlands by restoring or enhancing diminished or drained wetlands. Likewise, the CWA requires states to monitor and assess their surface waters to determine whether they are meeting water-quality standards and providing beneficial uses (Section 305). Wetlands, by definition, are waters of the state (Minn. R. Ch. 7050) and are thus subject to the same requirements under the CWA as lakes and streams. This has created a need for tools that can be used to assess the quality of Minnesota's wetlands.