Long-term vegetation development of restored prairie pothole wetlands

摘要: Although wetland restoration has been a key part of U.S. environmental policy for 20 years (i.e., “no net loss”), there is little long-term data on restorations to guide planning and assessment. Understanding how restored communities deviate from natural conditions, long those deviations persist, can provide important insights into the mechanisms recovery improve practice. This study reports results 19-year survey 37 prairie pothole wetlands in northern Iowa, southern Minnesota, southeastern South Dakota. Complete floristic surveys were performed each 1989, 1990, 1991, 2000, 2007. The accumulation species across all sites was greatest during first 12 after reflooding (14.4 species/year), which rate declined 1.6 species/year. Proximity semi-permanent water regime favored accumulations years, but changes since then are primarily linked regime. Semi-permanent have experienced fewer major gains losses richness, whereas temporary seasonal less stable. From 2000 2007, extinctions exceeded colonizations wetlands, resulting convergence beta diversity. 77% considered common region established these restorations, 70% infrequent not. likelihood that will eventually support many additional appears low, given presence barriers recovery, especially dominance invasive perennials (e.g., Phalaris arundinacea Typha angustifolia/x glauca) low colonization efficiency wet prairie, sedge meadow, woody perennial species. Management, such as active revegetation guilds, particularly meadow perennials, control needed ensure region’s biodiversity. restoration: isolation, flooding, species, factors do not self-correct over time need be addressed by establishing sound practices initial implementation vegetation management.