Natural Communities of the Saugatuck Dunes
John M. Fleming
Natural Communities of the NorthShore Property, Saugatuck, Michigan
Coastal Sand Dunes—The entire 413-acre NorthShore property is within the boundaries of Michigan’s designated Critical Dunes which are protected by State law and regulated by the Michigan Department of Natural Resources. The open dunes of the property provide nesting habitat for migratory birds such as the Prairie Warbler (MI-Endangered), Eastern Kingbird, Brown Thrasher, and Field Sparrow; and foraging habitat for migratory raptors such as the Northern Harrier (MI-Special Concern). In addition, Pitcher’s Thistle, a Federally Threatened wildflower, occurs on the NorthShore property and on adjacent park lands.
Interdunal Wetlands (or “Wetpannes”)—Considered Globally Imperiled by the Michigan Natural Features Inventory, these interdunal wetlands are scattered across the open dunes of both the north and south halves of the NorthShore property. At least 21 interdunal wetpannes occur in the Saugatuck Dunes—roughly a dozen wetpannes occur on the NorthShore property.
Wetpannes are a globally rare ecosystem. The Michigan Natural Features Inventory (MNFI) has listed interdunal wetpannes as having a “G2” global status, which means they are imperiled globally because of their rarity or because of some other factor (such as coastal development) that makes them vulnerable to extinction throughout their range. The size and location of the wetpannes on the NorthShore property has remained stable since as long ago as the turn of the last century. They can be seen in some of the earliest maps of the area (ca. 1900), and in the earliest aerial photographs (1938), and might be several hundred years old (see Sherfinski’s M.S. thesis at MSU in 2000 for a thorough study of these wetpannes).
These unique wetlands provide critical habitat for rare species such as Blanchard’s Cricket Frog (MI-Special Concern) and a rare wetland wildflower called Zigzag Bladderwort (Utricularia subulata) (MI-Threatened). Both have been documented on the NorthShore property by MNFI. According to MNFI, this site is one of just three known locations for Zigzag Bladderwort in Michigan. These interdunal wetpannes also provide stopover foraging habitat for migratory shorebirds along the coast of Lake Michigan.
Great Lakes Shore and Beach—Acquisition of the NorthShore parcel will protect over 1 mile of Lake Michigan shoreline and will connect together a stretch of nearly 4 miles of shoreline open to the public. This will benefit migratory shorebirds as well, including the Common Tern (MI-Threatened), Forster’s Tern (MI-Special Concern), plovers, and sandpipers which visit this shoreline during migrations.
Great Lakes Marsh—This wetland type is an herbaceous wetland plant community restricted to the shoreline of the Great Lakes and their major connecting rivers. This type of marsh, including its component wetland subcommunities (emergent cattail/bulrush marsh, submergent marsh, wet sedge meadows, and lowland shrub habitats), occurs on the NorthShore property along the north and west sides of the Oxbow Lake (the historic outlet of the Kalamazoo River that became a lake when the new channel was dug in 1906). These marshes provide nesting habitat for migratory waterbirds such as the Wood Duck, Blue-winged Teal, Mallard, and migratory passerines such as the Brown Thrasher, Chestnut-sided Warbler, Eastern Kingbird, and Great Crested Flycatcher. Bald Eagles (US-Threatened), Northern Harriers (MI-Special Concern), Black Terns (MI-Special Concern), American Black Duck, and Gadwall are known to use these marshes for foraging and stopover habitat. In addition, this is the only known location of Hibiscus moscheutos (a native marsh wildflower that is a species of Special Concern in Michigan) along the lower Kalamazoo River near Saugatuck. These marshes include potential nesting and stopover habitat for other species of concern, including American Bittern, Virginia Rail, Sora, Willow Flycatcher, Spotted Turtle (MI-Threatened), and Blanding’s Turtle (MI-Special Concern).
Riparian Shoreline and adjacent Marshes—Acquisition of this site will protect the shoreline of the Oxbow Lake and Kalamazoo River from destruction by incompatible development. The shore of the Oxbow Lake is very important habitat for the local population of Blanchard’s Cricket Frog (MI-Special Concern), Trailing Wild Bean (Strophostyles helvula) (MI-Special Concern), a native Hibiscus (Hibiscus moscheutos) (MI-Special Concern), migratory shorebirds, and native reptiles.