Wetland Restoration Takes Shape
Land clearing for the future site of the “Masi Commons” condominium/shopping center is well under way on the Southern 20 acres of the Jones Farm property. Or so a uniformed passerby might conclude from the major earth-moving operation that has taken place this spring. In fact, during a time when the forests and fields of Northeast Ohio are rapidly falling victim to suburban sprawl, the bulldozers and giant “scrapers” reworking the soil on the Jones Farm have been harnessed to bring about a very different outcome. Rather than houses, malls and roads, the objective here is to construct a series of wetlands that will: rejuvenate critical ecological services such as habitat for native plants and animals and nutrient retention, provide educational opportunities for students and community members, and result in a first class research facility that can be used to improve techniques for restoring wetland ecosystems elsewhere. A combination of grants and fellowships obtained through the Ohio EPA, USDA, and Ohio Department of Natural Resources [Is this correct Brad?] will allow for collaborations between EDIC, faculty from Oberlin College and faculty from Ohio State University to develop the educational potential of the project and to conduct much needed research on wetland restoration.
Why restore wetland ecosystems? Before European settlers arrived in the 1800s, the landscape of Northeast Ohio, including the Jones Farm, was dominated by wetland ecosystems. Settlers cut down forests and installed drainage tiles to move water off the land, lowering the water table by as much as five feet in some areas. This created valuable farmland, but also reduced native wetland species, and reduced natural ecological services provided by wetlands such as water purification. Today, converting less productive and abandoned farmland back into wetland ecosystems can be used to enhance habitat quality on the farm and improve water quality in downstream ecosystems. Together with the organic farm, orchard and managed forest, the work currently underway on wetland restoration is integral to the goal of using the Jones Farm to showcase the breadth of approaches that are collectively necessary to achieve sustainable land use in Northeast Ohio.
Wetlands are defined by the fact that the soil in them is saturated (i.e. completely wet) for all or part of the year. So the first critical stage in wetland restoration or creation is to get these hydrological conditions right. In the case of the Jones Farm, this has meant removing channels and tiles that were originally installed to drain water from the site and creating berms to impound the water in certain areas. Developing a wetland landscape that has a variety of hydrological conditions – some areas that are covered by water for all of the year, and some that dry seasonally – will maximize the potential for species diversity and diverse ecological function on the Jones Farm. A total of 18 acres have been prepared for wetland restoration.
Most of the earth moving activity has centered on creating six identical ½ acre research “cells” on the southernmost end of the restoration. Each of these adjacent cells is hydrologically isolated from the others (i.e. no water is exchanged between them) by a berm, contains shallow and intermediate depth habitats, and has a standpipe that can be used to precisely control water level independently of the other cells. Together, these features create a unique experimental system that can be used to test a broad range of hypotheses regarding the best way to restore and manage wetlands so as to maximize desirable habitat and function.
Once the appropriate hydrological conditions have been established, the second critical stage in wetland restoration/creation is establishing a plant community; the plants that come to occupy a site are crucial determinants of both the animal species and ecological functions and services that the wetland will support. Commercial wetland restoration efforts often rely on natural seed dispersal by wind and animals to supply the plants. Unfortunately, isolation from other wetlands in the landscape makes it difficult or impossible for many native species to find the site. When seeds are applied as part of the restoration effort, the commercial seed mixes used generally contain only one or a few plant species, and these species are often exotic and/or invasive. Even in cases where native species are actively planted, the impact of site history can make it difficult for these to become established and active maintenance programs that encourage natives and remove invasives are very rare. The net result is that two to three years after hydrological conditions are established, “restored” wetlands often contain nearly monotypic stands of species such as reed canary grass (Phalaris arundinacea), phragmites (Phragmites australis), and/or cattail (Typha sp.). These communities provide limited habitat for animals, and do not support the same diversity of functions and services as the more diverse communities typical of natural wetland ecosystems.
Because plant establishment is such a critical and often neglected component of restoration, the first series of experiments planned for the Jones Farm wetland cells will focus on different approaches to planting, seeding and management. Our objective is to design an experiment that will maximize opportunities for the broad range of researchers involved in this project (population, community, ecosystem and landscape-level ecologists), and will result in findings that are of practical use for other wetland restoration projects. The experimental design option that we are current considering will involve three different levels of planting and management. Specifically, two pairs of cells will be planted with a diverse assemblage of native wetland plants. One of these pairs will be intensively managed over the course of development so as to maintain maximal diversity and the other will be allowed to develop on its own after seeding. The third pair of cells will not be seeded at all, and will be allowed to “self-organize” through natural plant colonization. All three treatments will be weeded to prevent invasive species from taking over. Students and faculty will then trace the differences that develop over time among these treatments in plant and animal communities and in ecological functions such as nutrient and sediment retention. Within this experimental design there are also opportunities for studying the ecology and economics of edible wetland plants such as wild rice. Future experiments may focus on the water management, species composition and nutrient retention.
The OSU research team includes landscape/plant ecologist Martin Quigley and ecological engineer Jay Martin. Josh Smith, a masters student at OSU, will play a central role in planning and coordination during the first two years. Oberlin faculty involved in the project include John Petersen, David Benzing, Roger Laushman, Mary Garvin and Keith Tarvin. The EDIC team will be spearheaded by director Brad Masi. Through classes and independent study, Oberlin Students will play a critical role in the research. Next summer at least one Oberlin student will be hired to help manage the site and to begin developing an automated data collection system.
Long-term study of ecological development is critical to the advancement of the practice of ecological restoration. Unfortunately, due to the short duration of research funds this type of long-term research is very rare. The involvement of Oberlin faculty, and the fact that research and education are central missions of EDIC creates a unique opportunity for long-term study of ecological restoration at this site. The earth-moving component of the project has now been completed, and the wetlands cells have been planted with annual species that will stabilize the soil and begin to build organic matter. Planting of wetland species will begin this fall and resume next spring – stay tuned for volunteer opportunities.
[Suggested graphics: 1) photographs of earth moving equipment and wetland cells, 2) sketch (plan view) of the wetland w/research cells on southern end of the property.]