Restoration of headwater and coastal fens in the Lake Superior Basin of Upper Michigan.

摘要

In 2009, research projects were initiated at Michigan Technological University to develop restoration techniques for headwater fens and coastal wetlands in the southern Lake Superior Basin in Michigan's Upper Peninsula. The primary focus of these was to quantify the efficacy of using locally collected seeds as a technique for wetland restoration. Two primary sites were selected, the Sleeper Lake Fen complex in Luce County and the Portage Waterway-Keweenaw Bay region of Lake Superior in Baraga and Houghton Counties. At the Sleeper Lake site, a combination of heavy machinery, seeding and mulch application was used to restore a 1.6 km ditch through a formerly pristine headwater fen. Pore water chemistry was measured in the undisturbed and restored fen to compare with vegetation data collected from the same locations for two growing seasons following restoration. At the two coastal sites along the Portage Waterway and Keweenaw Bay, a combination of seeds, natural fiber geotextiles and organic soil amendment (milled Sphagnum peat moss) were tested for restoration efficacy along 2, 33-m long sectors of shoreline, one site along the Portage Waterway in Houghton County and another along a former interdunal pond adjacent to Keweenaw Bay in Baraga County. Vegetation data were collected for three years following restoration. Both projects were successful in restoring diverse assemblages of native plants. At the Sleeper Lake site, pore water chemistry was found to correlate closely with several vegetative parameters and at the Portage Waterway and Keweenaw Bay sites, the organic amendment had variable results in enhancing vegetative establishment and survival. Fluctuating lake levels were important in determining vegetative establishment and survival at the sites along Lake Superior. The results of these experiments are compared with other similar projects and discussed in relation to local conditions and potential for extrapolation across the Great Lakes region.