Regional Landscape Ecosystems of Michigan, Minnesota, and Wisconsin
SUB-SUBSECTION VIII.3.1. Northern Lake Michigan (Hermanville) Till Plain
DISCUSSION: The topography of the sub-subsection consists of a broad plain of loamy ground moraine. Soils are rocky, and limestone bedrock is generally less than 50 feet below the surface. Drumlin ridges, trending northeast-southwest, characterize most of the sub-subsection in Michigan; but they are uncommon in Wisconsin, where the landscape consists of a gently sloping till plain.
ELEVATION: 580 to 1,250 feet (177 to 381 m).
AREA: 3,880 square miles (10,057 sq km).
STATES: Michigan and Wisconsin.
CLIMATE: The temperature is moderated by Lake Michigan. In Wisconsin, the growing season is nearly 150 days along Lake Michigan, but only 120 days at the west edge of the sub-subsection (Hole and Germain 1994). In Michigan, the growing season ranges from 140 days in the south, to shorter than 100 days in the north (Eichenlaub et al. 1990). Extreme minimum temperature ranges from -32½F in the south, near Lake Michigan to -40½F in the north, farther inland. Influence of the Great Lakes is less here than in the rest of the subsection; snowfall is relatively light, 60 to 80 inches annually in Michigan (Eichenlaub et al. 1990) and 40 to 60 inches in Wisconsin (Wisconsin Statistical Reporting Service 1967). Average annual precipitation is relatively uniform, from 28 to 32 inches.
BEDROCK GEOLOGY: Paleozoic limestone and dolomite are generally within 30 feet of the surface, accounting for the rocky nature of the glacial drift and also the nutrient-rich, sandy loam soils (Vanlier 1963b, Sinclair 1960). Surface deposits of glacial drift reflect the local bedrock from which the till was derived; the bedrock in the northern third of Michigan is Cambrian sandstone, and bedrock in the remainder of Michigan and Wisconsin is limestone and dolomite. Bedrock close to the surface in Michigan accounts for the high percentage of wetland within the sub-subsection.
LANDFORMS: A broad till plain (ground moraine). In Michigan, drumlins oriented northeast-southwest cover much of the plain, but there are few drumlins on the undulating till plain in Wisconsin. Drumlin ridges are typically one-eighth to one-fourth mile wide, less than a mile long, and 20 to 60 feet high (Albert et al. 1986). The highest drumlins are less than 100 feet high. Wetlands are extensive throughout the sub-subsection, but they have been more extensively drained for agriculture to the south in Wisconsin than elsewhere.
LAKES AND STREAMS: A few small, linear lakes, trending southwest-northeast; many large, shallow wetlands also trending southwest-northeast. Many small rivers and creeks drain the numerous linear wetlands of the sub-subsection. Large rivers: Oconto, Peshtigo, and Menominee.
SOILS: Dominant soils are rocky, podzolized, pink sandy loams. Peat and muck soils are common. Soils on the drumlins are generally well to moderately well drained; but some of the smaller, more gently sloping drumlins can have poorly drained soils (Albert 1990). Soils are classified primarily as Spodosols and Alfisols (Hole 1976). In Wisconsin, Typic Hapludalfs are common; farther north in Michigan, Haplorthods and Fragiorthods are predominant (USDA Soil Conservation Service 1967).
PRESETTLEMENT VEGETATION: On the loamy drumlins and undulating ground moraine were northern hardwood forests of sugar maple, beech, hemlock, northern white-cedar, and yellow birch (Albert 1990). Hemlock and white pine were much more common here than on the clay plain of Sub-subsection VIII.1.4 to the southeast. In Michigan, hemlock and occasionally northern white-cedar formed upland stands. Small drumlins within wetlands were often dominated by either hemlock, white pine, or a mix of the two.
In Michigan, wetlands covered all but the drumlin ridges, accounting for 30 to 70 percent of the land surface. A cross section of the flat plain between the drumlins had northern white-cedar and tamarack at the margins of the drumlins (on poorly drained mineral soil or shallow organic soils) and black spruce and open bog or wet meadow at the center of the plain (on very poorly drained peats or mucks).
At the northern edge of the sub-subsection in Michigan, where the texture of the drumlin ridges was sand, the dominant vegetation was originally a mixed red, jack, and white-pine forest. Logging followed by fire converted most pine forests to bigtooth aspen.
NATURAL DISTURBANCE: Windthrow was common, both in Michigan and Wisconsin, occurring both on the isolated drumlin ridges and within the vast wetlands (Comer et al. 1993a, Canham and Loucks 1984).
PRESENT VEGETATION AND LAND USE: Early logging of white pine occurred in the sub-subsection; later, agriculture predominated. Until the early 1980's, pasture was the primary agricultural use, but hybrid corn is now being planted on many uplands.
RARE NATURAL COMMUNITIES: None identified to date.
RARE PLANTS: Michigan and Wisconsin: Ranunculus cymbalaria (seaside crowfoot). Michigan only: Danthonia intermedia (wild oat-grass), Linum sulcatum (furrowed flax). Wisconsin only: Carex formosa (handsome sedge), Trillium nivale (snow trillium).
RARE ANIMALS: Michigan and Wisconsin: Alces alces (moose). Wisconsin only: Ophiogomphus howei (pygmy snaketail), Acipenser fulverscens (lake sturgeon).
NATURAL AREAS: Michigan: Michigan Nature Association Preserves: Daubendiek Memorial (Escanaba River alvar). Wisconsin: State Natural Areas: Poppy's Rock, Tellock's Hill Wood, Mukwa Bottomland Forest, Charles Pond, Hortonville Bog, Bloch Oxbow, Shaky Lake.
PUBLIC LAND MANAGERS: Michigan: State Forests: Escanaba River, Copper Country; National Forests: Ottawa, Upper Peninsula Experimental Forest. Wisconsin: State Wildlife Areas: Green Bay Shores, Navarino.
CONSERVATION CONCERNS: Very little biological survey has been done within the sub-subsection. The calcareous substrate should provide habitat similar to that found along the Great Lakes shorelines, but there are few or no records of many of the threatened plants one would expect in such habitats. This sub-subsection is considered very important to the deer herd of northern Michigan, due to the excellent juxtaposition of upland and wetland conifers for winter cover and food. Commercial forestry logging practices destroyed most of the mature upland hemlock stands during the 1980's, causing public concern. The logging of mature conifers may have also been detrimental to migratory song birds, especially some of the warblers. The large amounts of remote conifer swamp in the northern part of the sub-subsection may provide significant habitat for large mammals and migratory song birds.
Previous Section -- Subsection VIII.3. Dickinson
Return to Contents
Next Section -- Sub-subsection VIII.3.2. Gwinn
