Chicago Botanic Garden

Lake Ecosystems

Lakes and ponds in urban areas face an onslaught of stressors that threaten their beauty as well as their ecological integrity. The Garden enhances our lakes using a wide range of techniques, and in so doing, demonstrates to public and professional audiences effective ways to restore and protect urban lake ecosystems.

Of the Garden's 385 acres, nearly one-quarter is water, including a 60-acre system of lakes with six miles of shoreline. A 1998 study revealed that 80 percent of the Garden's lakeshores were experiencing moderate to severe erosion. Other problems included excessive nutrient loading (primarily from nuisance levels of Canada geese), rough fish impacts (primarily carp) and invasive plants. Steep shoreline slopes, weakly rooted near-shore plants (often turf grass) and poor soils dominated our lakeshores.

PHOTO: restored lake The Garden researches innovative ways to enhance lake habitat, including creating shallow-water planting "shelves" that extend out from the water's edge. Rolls of coconut fiber were installed parallel to shorelines to dissipate the erosive energy of waves and protect new plantings. Boulders were placed in the water to help absorb wave energy, and space was provided behind and between them for emergent aquatic plants with dense root systems. The Garden pioneered the use of several geotextile products to help protect its new shoreline plantings. A Geoweb® plastic product was placed along the shoreline to help prevent failure of shoreline slopes, particularly during high water. A plastic "benthic mesh" was installed in shallow water to protect new plantings' roots and crowns from thrashing behavior exhibited by carp during their spawning period. The Garden's shoreline planting palette focuses almost exclusively on tough, resilient native species. The plant taxa are chosen for their ability to anchor shoreline soils and withstand environmental stresses inherent to urban waterways, as well as their color, texture and four-season interest. The plants are carefully arranged into modest-sized drifts within the shoreline zone, with the result being ecologically functional landscapes that offer a widely accepted aesthetic appeal.

Through the Joseph Regenstein, Jr. School of the Chicago Botanic Garden, courses, workshops and seminars help landscape and conservation professionals understand how ecological and horticultural principles can be joined to create sustainable water landscapes. And for the visiting public, a strategic system of interpretive signage, interactive workshops and website information help expand their knowledge of aquatic horticulture and environmental conservation.

Top Photo: R. Kirschner