Regional Landscape Ecosystems of Michigan, Minnesota, and Wisconsin

DISCUSSION: Subsection VII.4 lies along the west coast of the State. Although it is physio-graphically diverse, the entire subsection has a climate moderated by Lake Michigan, resulting in intense agricultural use of the lands for vineyards and orchards. The subsection includes five islands: North and South Manitou, North and South Fox, and High. The western edges of all of these islands contain large areas of perched sand dune, and most of each island consists of either dunes or other lacustrine physiographic features.

SUB-SUBSECTIONS: none.

ELEVATION: 580 to 1,150 feet (177 to 350 m).

AREA: 1,435 square miles (3,715 sq km).

STATES: Michigan.

CLIMATE: A strongly lake-modified climate results in a long growing season of 140 to 150 days (Eichenlaub et al. 1990). This, coupled with retarded spring warming, makes the climate suitable for commercial fruit production. Extreme minimum temperature ranges from -32½F at the southern edge of the subsection and along the Lake Michigan shoreline to -42½F along the eastern edge in Lake County. Lake-effect snowfalls are heavy, averaging 100 to 140 inches. Average annual precipitation is 32 to 34 inches.

BEDROCK GEOLOGY: No exposed bedrock; glacial drift thickness ranges from 400 to 700 feet. The underlying bedrock is Paleozoic, Mississippian gypsum, sandstone, and shale, and Devonian sandstone, shale, dolomite, limestone, and evaporites (Dorr and Eschman 1984, Milstein 1987).

LANDFORMS: Diverse topography, including sand dunes, sand lake plain, ground and end moraines, and outwash. Morainal bluffs and sand dunes rise abruptly along the shoreline of Lake Michigan. The shoreline is noted for these large sand dunes, which can be as high as 600 feet. Some of the best known dunes are those of the Sleeping Bear Dunes National Lakeshore and Ludington State Park. The high dunes, which date from high Lake Nipissing water levels (Kelley 1962), are also found on North and South Manitou Islands and on South Fox Island. Most of the high dunes are perched on underlying till, which is exposed as steep bluffs along the lakeshore.

Coarse-textured endmoraine ridges are the predominant landforms in the south and also north of Manistee. At Manistee, a broad flat area of lake plain and ground moraine separates the more steeply sloping moraines into northern and southern parts. In the south, the end moraines, 3 to 5 miles wide and 100 to 300 feet high, are separated by wide outwash channels. North of Manistee, the endmoraine ridges are much steeper than ridges in the south and without broad outwash channels between them. Most of the soils on the end moraines are well-drained sands.

Between Manistee and Frankfort, resistant bluffs of medium-textured till rise steeply from the lake, forming moderately to steeply sloping end moraine ridges. To the east of these ridges are steep ridges of sandy soil.

In the southern half of the subsection, there are small areas of more gently sloping, fine-textured ground and end moraines. Most of the soils are well drained.

Between Ludington and Manistee is a broad expanse of flat sand lake plain and fine-textured ground moraine. Much of the lake plain consists of wet depressions and small, droughty beach ridges. Most of the ground moraine is poorly drained.

LAKES AND STREAMS: Sand bars and low dunes separate several large lakes from Lake Michigan; these lakes were once large bays of Lake Michigan, but as water levels dropped, they became separated. Examples are Manistee Lake on the Manistee River, Portage Lake on the Portage River, Glen Lake on the Crystal River, Pentwater Lake on the Pentwater River, Pere Marquette Lake on the Pere Marquette River, and Hamlin Lake on the Big Sable River. A few small lakes also occur on moraines and outwash.

SOILS: The dune soils are excessively well drained sands that contain no fine silts or clays. Most of the soils on the moraines are sands, but there are both medium-textured and fine-textured soils on the moraines. In the south, the soils are classified as gently sloping Haplorthods plus Glossoboralfs; in the north, soils are moderately sloping and there are also Udipsamments (USDA Soil Conservation Service 1967).

PRESETTLEMENT VEGETATION: The dunes were noted by GLO surveyors as "loose sands" at several places along the coast; they were undoubtedly partially vegetated with dune grasses and shrubs. Farther inland the dunes supported various forests, including upland hemlock, hemlock-white pine, white pine-red pine, and red pine-jack pine-dominated forests. Northern hardwood forests, often with a significant component of hemlock and/or black oak, were also common. Poorly drained interdunal areas often supported northern white-cedar and/or hemlock-dominated swamps and shrub swamps.

On sandy lake plain and sandy moraines, eastern hemlock and American beech were often co-dominants. Other upland parts of the sandy lake plain included forests of white pine, which included significant amounts of white oak, beech, hemlock, black oak, and white ash. Several large complexes of beach ridges and swales, extending as much as a mile inland, supported various upland/wetland plant communities.

Poorly drained parts of the sandy lake plain supported swamps containing various combinations of black ash, elm, trembling aspen, tamarack, northern white-cedar, and hemlock. Thickets of willow, speckled alder, and bog birch, and emergent marshes also occurred on the sandy lake plain. Extensive marshes formed in the shallow inland lakes that formed at the mouths of major rivers, such as the Manistee and Big Sable.

Most of the moraines, regardless of their soil texture, supported forests of northern hardwoods. Dominance of northern hardwoods was probably a result of the increased precipitation and reduced transpiration along Lake Michigan (Denton and Barnes 1987, Eichenlaub 1979), allowing beech, sugar maple, and basswood to dominate sandy soils where oaks and pines would otherwise be expected.

Fine-textured ground moraine supported forests of eastern hemlock. Poorly drained areas with finer textured soils supported black ash, black spruce, and cedar swamps.

Sandy outwash deposits supported forests of white pine, red pine, and white oak, or on more fire prone sites, red pine with jack pine.

NATURAL DISTURBANCE: Although many of the high coastal dunes have been stabilized by forest vegetation, large blowouts are common on the dunes next to Lake Michigan. Some of these blowouts are the product of human disturbance; but many, noted by GLO surveyors, are probably naturally caused. The blowouts are large features, often extending as much as a half mile inland.

Signs of wildfires on sandy outwash deposits were noted several times by surveyors. Occasional, relatively small windthrows were encountered on the moraine ridges of the subsection.

PRESENT VEGETATION AND LAND USE: The dunes are largely managed as recreational lands, including State and federal parks. Residential development is also popular on the dunes.

White pine and red pine were extensively cut from the lake plain. The flat, sandy lake plain supports second-growth forest, used both for timber and recreation. Pine regeneration has generally been poor on the pine plains, with trembling aspen, red maple, and paper birch increasing in dominance after logging. There were attempts to establish orchards and farms on the sand lake plain after logging, but low productivity and easily eroded soils have resulted in high rates of abandonment.

The protection from late spring frosts afforded by Lake Michigan is responsible for the use of the subsection for extensive orchards of apples, cherries, and peaches (Olmsted 1951). Sand mining occurs on the dunes within the subsection, and oil fields tap the underlying Devonian petroleum reservoirs in the south. Urban development has been concentrated along the shoreline in the town of Manistee and several other smaller towns.

RARE PLANT COMMUNITIES: None identified to date.

RARE PLANTS: Botrychium campestre (prairie dunewort), Bromus pumpellianus (Pumpelly's brome grass), Cirsium pitcheri (Pitcher's thistle), Mimulus glabratus var. Michiganense (Michigan monkey-flower), Orobanche fasciculata (fascicled broom-rape), and Scirpus hallii (Hall's bulrush).

RARE ANIMALS: Buteo lineatus (red-shouldered hawk), Charadrius melodus (piping plover), Clonophis kirtlandii (Kirtland's snake), Dendroica discolor (prairie warbler), Lanius ludovicians (loggerhead shrike), Lycaeides melissa samuelis (Karner blue), Trimerotropis huroniana (Lake Huron locust).

NATURAL AREAS: Wilderness Areas: Nordhouse Dunes (and Research Natural Area, Forest Service), Michigan Islands; The Nature Conservancy Preserves: Betsie River, Point Betsie, Lucia K. Tower.

PUBLIC LAND MANAGERS: State Parks: Charles Mears, Ludington, Silver Lake, Orchard Beach; State Game Areas: Betsie River, Manistee River, Muskegon, Pentwater; State Forests: Pere Marquette; National Forests: Manistee; National Lakeshores: Sleeping Bear Dunes; Other: Beaver Islands Wildlife Research Area, High Island Environmental Area, Central Michigan University Biological Station.

CONSERVATION CONCERNS: Large areas of coastal dune, including both open and forested dunes, have been protected within State parks. Investigation for Michigan monkey-flower continues in seepages along the Lake Michigan shoreline and inland, cold, spring-fed streams.