Native Plant Assessment for Restored Lake Shorelines at the Chicago Botanic Garden
Scenic water vistas and diverse aquatic habitat are defining landscape elements throughout the Chicago Botanic Garden’s 60-acre system of interconnected lakes. Beginning in 1999, the Garden has engaged in a systematic rejuvenation of its lake shoreline using innovative bioengineering techniques. These approaches rely heavily on dense stands of native vegetation to control erosion of fragile lakeshore soils, establish ecologically diverse communities of native shoreline plants, enhance wildlife habitat, and demonstrate the importance of healthy lake ecosystems for visitors. To date, 4.5 miles (79%) of the Garden’s lakeshore have been rejuvenated using ½-million native shoreline plants.
Intensive scientific studies in 1998 documented serious threats to the Garden’s lakes, noting in particular the poor stability of shoreline soils and the near-absence of native shoreline vegetation. Over 80 percent of the Garden's lakeshores were experiencing moderate to severe erosion. Excessive nutrient loading, rough fish activity (primarily carp) and invasive submerged plants (especially Eurasian water milfoil) further contributed to degraded water quality and aquatic habitat.
Aquatic habitat and wetland plantings along the Garden’s lakeshores—previously measured in inches—now extend 50 feet or more. Innovative approaches for creating stable, shallow-water shelves along the lakeshore allow the new native plants to flourish and anchor shoreline soils. The projects’ planting palette, representing 210 species of native perennials and 34 species of native shrubs, focuses on resilient "workhorse" species that are carefully chosen for their ability to anchor shoreline soils and withstand environmental stresses inherent to urban waterways. By placing the plants in modest-sized drifts, the result has been ecologically functional lakeshore landscapes that offer a widely accepted aesthetic appeal. Creative uses of interplanted stones and boulders, as well as specialized plastic mesh and webbing materials, further help stabilize the shoreline edge and protect the newly installed aquatic plantings. Nutrient reduction strategies, including fertilizer management and nuisance waterfowl control, have lowered in-lake phosphorus concentrations by more than 50 percent.
Both private and public funds have been used to support the Garden’s ambitious efforts including significant assistance from the U.S. and Illinois Environmental Protection Agencies, the U.S. Army Corps of Engineers, the Illinois Department of Natural Resources, and the Woman’s Board of the Chicago Horticultural Society. The shoreline restoration efforts have received widespread recognition and commendation at the regional, state, and national levels.
The restored shorelines demonstrate to public and professional audiences innovative and effective approaches for restoring and protecting urban lake ecosystems – while serving as a living laboratory for Garden scientists and their colleagues studying urban water resource conservation.
The student engaged in this REU project will assist another student from Brown University who will be conducting a comprehensive assessment during summer 2015 of all plantings along the restored shorelines. Plant survival, plant density, and plant/root vigor data will be collected for each taxa located in a series of approximately 2,000 discrete planting bed locations along 4.5 miles of the Garden’s restored lakeshore. The REU student will be provided with an exceptional opportunity to learn identification of over 200 taxa of native aquatic/wetland plants while gaining a detailed understanding of shoreline ecology and lake shoreline erosion control strategies.
More information about this project can be found at: