Swales

Swales are the low wet areas between the dunes. They have their own succession of plant communities, with rushes, sedges, and marsh grasses as their pioneers. Dwarf birch and Red Osier Dogwood grow in more mature swales, followed by willows and cottonwoods and ultimately these swales will support Black Oaks. These wetlands are home to a variety of plants including sundew, many orchid species, and Kalm’s St. John’s-wort. Several species of frogs can be found in these areas, as well as birds, reptiles, and aquatic insects such as dragonflies.

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Between the ridges that run parallel to the lakeshore are low areas called swales.

swale
Swale at Illinois Beach State Park

 

Plants that can tolerate growing in very sandy soil, like rushes, sedges, and marsh grasses, often grow in wet swales near the shore. As you move west away from the shore, the swales are progressively older. A greater diversity of plants can live in these swales, because their sandy soil has been enriched by humus (decayed plant material). Some swales are either alkaline or acidic, and are home to these unique plants:

Tread gently

Approach a swale slowly and quietly and you might catch a glimpse of several kinds of frogs and aquatic insects like dragonflies.

Buffet for birds

With frogs and insects everywhere, swales are ideal places for birds to forage for food. The bird species you’ll see in swales often varies based on the plants available for shelter and nesting.