Shoreline Restoration, Rain Gardens, Wetland Restoration
Native plants have spent thousands of years adapting to the various conditions of our climate and topography, including the edge of our streams, rivers, shorelines, and wetlands.
Such watersheds are among the most biologically diverse communities we have in the Midwest. When healthy, they constitute an ecosystem of plants and animals that contribute to the long-term stability of the lakes, rivers, and wetlands.
Wetlands work as a huge sponge that first filters and then retains water. Such reservoirs allow water to infiltrate the soil more quickly and evaporate, allowing for more stable climate conditions and a more stable water supply. Water filtration and retention is critical for future drought cycles.
Two Challenges to Water Filtration: Turf Grasses and Reed Canary Grass
Unfortunately, our native grasses and wildflowers, and hence the fauna that depend upon them, have been greatly reduced in these vital areas for primarily two reasons: residential development along lakes with turf grass replacing native species, and the introduction of aggressive non-native plants that thrive in more undeveloped areas.
Reed Canary Grass and Brome Grass were introduced at the end of the 19th century as pasture grasses. Both develop a very thick root structure and so are very effective at stabilizing soil and are good for haying. But Reed Canary Grass in particular establishes itself in wet terrains such as wetlands and waterways, as well as in uplands.
It is an aggressive plant, by which we mean it can quickly take over an area, excluding all other plant species. This elimination of all other plant life, in turn, reduces insect and animal species, resulting in a diminished ecosystem.
The benefits of creating shoreline and waterway buffer strips, rain gardens, and restoring wetlands are many: they filter rain run-off; create plant and insect biodiversity; prevent erosion; and increase water infiltration. It is vitally important that we revitalize those places where water and earth meet.
Shorelines: A Balancing Act
Conventional landscape practices such as turf grass yards, sandy beaches, and vegetation-free shorelines have diminished the biological diversity upon which watershed ecosystems depend. The maintenance of turf grasses contributes to phosphate runoff, lakeshore erosion, and loss of habitat for insects, birds, and animals. Sandy beaches eliminate habitat, increase erosion, and decrease water clarity, as does the elimination of aquatic plants.
At the same time, turf grass, beaches, and open water contribute to our enjoyment of our lakeshore environments. Fortunately there are ways of designing our lakeshore landscapes that satisfy the needs and enjoyment of all creatures—human and non-human alike. The primary and most effective way to preserve and enhance our lake ecosystem and our ability to enjoy it is the creation of buffer zones.
A buffer zone is “an area that may extend from 25 to 100 or more feet from the water’s edge onto the land and 25 to 50 feet into the lake, depending on the circumstances at a given site” (p. 31, Landscaping for Wildlife and Water Quality, Minnesota’s Bookstore, 1998). At least 50%, but 75% of a shoreline should act as a buffer if possible. A buffer zone has two components: aquatic plants descending from the shore into the water and upland plants from the shore moving upland.
The upland buffer zone consists of native grasses, sedges, and wildflowers that are adapted from damp to dry soil conditions. These work to filter grass clippings, lawn chemicals, and animal feces from the runoff as it makes its way through the watershed, as well as provide critical habitat to beneficial microorganisms and insects. It also allows rain water to penetrate into the soils more efficiently, a process we call “infiltration.” Aquatic plants, such as sedges, Blue Flag, bulrushes, and cat-tails, reduce erosion by buffering the shore from waves and also provide habitat for aquatic species, beginning with phytoplankton (algae), which provides food that runs up throughout the food chain.