Wetland communities occur where water collects in low areas of the landscape. The plants that live in wetlands are special—they must be able to adapt to changing water conditions, and they must be able to survive in the low-oxygen environment of waterlogged soils. And wetland soils are unique. As plants die and fall into the water, breakdown of the plant material is slowed by lack of oxygen. As a result, wetland soils contain a high percentage of partly decomposed plant material, called peat. Because they are rich in nutrients, wetlands are an important habitat for a rich variety of plants and animals.
Because wetlands are naturally uncommon on the North Shore and because many wetlands have already been lost to development, staff from the Minnesota Department of Natural Resources (DNR) felt it was important to try to restore the wetland community that previously existed at Sugarloaf Cove. In 1998 the DNR received a grant from the Great Lakes National Program Office of the Environmental Protection Agency to carry out the wetland restoration project.
The first step of the project was to verify that a wetland had existed on the tombolo and to determine what kind of plants were part of that community. In February 1998, American Engineering Testing of Duluth, Minnesota, drilled eighteen geotechnical soil borings across the tombolo to examine the subsurface soil conditions. DNR Project Manager Pat Collins examined the soil samples as they were collected. Peat was encountered in six of the borings. The thickness of the peat layer ranged from less than 1 foot to a maximum of 2 feet. Groundwater was encountered in four borings; depth to groundwater varied from 3.8 feet to 6.5 feet below the ground surface. Fill thickness also varied across the site, with a maximum of 5 feet. Based on the information collected during the drilling project, it was concluded that the buried peat layers were thin and discontinuous, but they did indicate that a wetland had probably existed at the site in the past.
Based on all the information collected from the soil boring investigation, it was concluded that the most protected portion of the interior of the tombolo complex was probably occupied by a sedge-mat or shrub-carr wetland, surrounded by a dynamic forested upland. The forest community apparently included mostly conifers such as black spruce and balsam fir with some white cedar and white pine, alder, and a few birch.
A team consisting of Peterson Environmental Consulting, Inc., Stevens Drilling and Environmental Service, Inc., and Booming Native Plants was hired to carry out the restoration project. Plans called for only a portion of the tombolo to be restored, so after the wetland community type had been identified, another field investigation was undertaken to identify the limits of the area to be restored. Under the watchful eyes of engineer Diane Desotelle and soil scientist Jim Arndt of Peterson Environmental, thirty-four additional auger borings and several shallow pits were completed in order to identify the area within the tombolo that had the best potential for restoration.
In addition to restoring the wetland, a secondary goal of the project was to eliminate the old road that connected the upper landing with the lower landing/tombolo and to eliminate the cut at the base of the hill where the Consolidated Papers office building had stood. To accomplish this secondary goal, the fill material that was removed from the restoration project area was placed in the roadbed and the former building site. Silt fences and brush were carefully placed across the old roadbed to control erosion until stabilizing plants could become established. Logs were scattered throughout the wetland area to provide nurse logs and to minimize erosion.
Once the topography was restored in the wetland, hillside, and roadbed, it was important to introduce native plants to cover the exposed soil before weeds could take over.
Frank Kutka of Booming Native Plants collected seeds from local native flowers and grasses; to make sure the plants were well-adapted to local conditions, seed collecting was restricted to an area within 25 miles of Sugarloaf Cove. Some of the seeds were spread on site immediately, and others were taken to Kutka’s nursery to be sprouted during the winter for planting in the spring.
Coordinated by SICA’s Executive Director, Terri Port Wright, volunteers from across the state came to Sugarloaf Cove to plant thousands of seedlings in the restored wetland in late May, 2000. In addition to members of SICA, volunteers came from Cook County schools, Full Circle, the Great Lakes Aquarium in Duluth, and the Minnesota Chapter of The Nature Conservancy.
Additional mature plants were transplanted from nearby sites where landowners had given permission. When planting, the seedlings were carefully placed in their preferred soil conditions—wet, transitional, or dry. Plants were watered as frequently as needed based on weather conditions.
Survival of the seedlings will depend on many factors, including moisture conditions, competition from weeds, and browsing by deer and rabbits. To give the new plants the best possible start, they were planted close together to make it more difficult for weeds to get started. In addition, native species that do well in disturbed areas were used, and fences (called exclosures) were erected in some areas to keep deer and rabbits from eating the new plants. Nurturing of the young plants will continue for many years.