Regional Landscape Ecosystems of Michigan, Minnesota, and Wisconsin
SUB-SUBSECTION VIII.2.1. Seney Sand Lake Plain
Very poorly or excessively drained sand lake plain, transverse dune, outwash; shallow, paludified peatlands (many patterned), jack pine barrens, hardwood-conifer and conifer swamp.
DISCUSSION: This sub-subsection of sand lake plain contains the largest expanses of wetland in the State. Landforms of lacustrine origin typify the sub-subsection.
ELEVATION: 600 to 880 feet (183 to 268 m).
AREA: 1,662 square miles (4,307 sq km).
STATES: Michigan.
CLIMATE: The climate is dominated by lacustrine influences near its margins, but an extreme frost pocket is near the center of the broad wetlands. Growing season ranges from less than 100 days in the center of the frost pocket to approximately 130 days at the northern and southern edges (Albert et al. 1986, Eichenlaub 1990). The growing-season heat sum (1,800 degree C-days) is one of the lowest in the State (Albert et al. 1986, Denton 1986). Extreme minimum temperature is -46½F near the center and -36½F at the north and south edges. Average annual precipitation is 32 to 34 inches. Annual snowfall is between 80 and 160 inches; the greatest amount is in the north nearer Lake Superior, and the least is at the southern edge (Eichenlaub et al. 1990).
BEDROCK GEOLOGY: Bedrock is typically covered by 100 to 200 feet of glacial drift, but is near the surface along the western edge. Ordovician- and Silurian-age limestone, dolomite, and other sedimentary rocks of marine or near-shore environments underlie the entire sub-subsection (Sinclair 1959, 1960; Reed and Daniels 1987).
LANDFORMS: Landforms of lacustrine origin. Broad, poorly drained embayments contain beach ridges and depressions (swales), sand spits, transverse sand dunes, and sand bars. Deltaic deposits occur along the northern margins of the embayments, where glacial meltwater streams carried massive amounts of sand into the shallow waters.
LAKES AND STREAMS: Many rivers originate in the wetlands here. All these rivers meander, creating broad oxbows on the flat landscape. Most of the rivers, including the Manistique, Fox, Driggs, Creighton and Sturgeon, flow to the southeast, perpendicular to the regional bedrock slope.
SOILS: Peats, poorly drained sands, excessively drained sands. Excessively drained sand soils occur on level lake plain, outwash plains, and transverse dune ridges.
PRESETTLEMENT VEGETATION: Marshes, peatlands, and low productivity swamps were the predominant vegetation on the very poorly drained topography, as noted by GLO surveyors (Albert 1990, Comer et al. 1993a). Many of the broad wetlands occupy embayments of Glacial Lake Algonquin (10,000 years B.P.), but peat began to accumulate only during the moister, cooler climatic conditions of the last 3,000 to 4,000 years (Futyma 1982). Jack pine dominated the droughtiest outwash plains; red pine, white pine, and bigtooth aspen occupied the seasonally moist lake plains and the transverse dunes (Comer et al. 1994).
NATURAL DISTURBANCE: Based on the surveyors' notes, fires occurred regularly on both the extensive peatlands and on the transverse dunes within the peatlands. The fires were probably not extreme on the dunes because of their steep slopes. Beaver floodings were quite common, with several noted within a single peatland.
PRESENT VEGETATION AND LAND USE: Much of the land here is part of either a State or national forest or Wildlife Refuge; land management is primarily for timber or wildlife. The original logging occurred shortly after 1900 for much of the area; white pine and red pine were logged from the uplands, and northern white-cedar was logged from margins of the wetlands.
In the early 20th century, attempts were made to drain and farm parts of the wetlands that are now the Seney National Wildlife Refuge. These attempts failed due to low soil productivity, soil erosion, and the extremely short growing season. During the Seney fire in the 1970's, the peat fire was difficult to extinguish along the drainage ditches, where the peat was dry enough to smoulder and burn to great depths.
RARE PLANT COMMUNITIES: Almost all the State's patterned peatlands occur here.
RARE PLANTS: Amerorchis rotundifolia (round-leaved orchid), Danthonia compressa (flat oatgrass), Eleocharis nitida (slender spike-rush), Juncus vaseyi (Vasey's rush), Oryzopsis canadensis (Canada rice-grass), Petasites sagittatus (sweet coltsfoot), Vaccinium cespitosum (dwarf bilberry).
RARE ANIMALS: Coturnicops noveboracensis (yellow rail).
NATURAL AREAS: Research Natural Areas (Hiawatha National Forest): Northern Hardwoods, Betchler Tamarack Swamp (proposed), Shingleton Bog (proposed); Wilderness Areas: Delirium (Hiawatha NF); Michigan Nature Association Preserves: Huntington Memorial, Walker Memorial, Cedar Lake.
PUBLIC LAND MANAGERS: National Forests: Hiawatha; National Wildlife Refuges: Seney; State Forests: Superior; State Environmental Areas: Duck Lake, Rock Island.
CONSERVATION CONCERNS: The peatlands of the sub-subsection are among the largest and least developed wetlands of the State. At present, there appears to be little threat of development, but some have proposed drainage for planting of hybrid larch. Parts of the Seney National Wildlife Area have been hydrologically altered in the past, and there are proposals to dynamite potholes into some of the peatlands of the sub-subsection to create areas for waterfowl breeding. Many of the large patterned peatlands have been inadequately surveyed for biotic diversity. The large, shallow peatlands are breeding habitat for sandhill cranes.
BOUNDARIES: This sub-subsection is further divided into several finer mapping units in the Hiawatha National Forest's Ecological Classification System.
Figure 24.—Sub-subsection VIII.2.1: Indian River Pines, Schoolcraft County, Michigan. Poor drainage characterizes much of the sand lake plain and outwash of this sub-subsection. Here, red pine and white pine form small groves on islands of drier outwash surrounded by sedge-dominated wet meadows and shallow peatlands. Many of the wetlands are quite young; they were dominated by upland conifers until 3,000 to 4,000 years ago, when cooler, wetter climatic conditions resulted in the transformation of upland forests to wetlands. Photo by D. Albert.
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