Regional Landscape Ecosystems of Michigan, Minnesota, and Wisconsin

SUBSECTION VI.4. Ionia

Medium- and coarse-textured moraines; forests of beech-sugar maple (and black maple) and oak-pine, conifer and deciduous swamp forests.

DISCUSSION: The subsection consists of two sub-subsections.

SUB-SUBSECTIONS: Lansing (VI.4.1), Greenville (VI.4.2).

ELEVATION: 640 to 1,122 feet (195 to 345 m).

AREA: 5,864 square miles (15,192 sq km).

STATES: Michigan.

CLIMATE: Growing season ranges from approximately 130 days at the northern edge of the subsection to 160 days at the western edge (Eichenlaub et al. 1990). It is the least lake-moderated subsection in Section VI (Albert et al. 1986). Average annual precipitation ranges from 30 to 32 inches, and average annual snowfall ranges from 40 to 80 inches, with highest levels in the west near Lake Michigan. Extreme minimum temperature ranges from -24½F to -36½F. In general, the extreme minimum temperature becomes lower farther north in the subsection, but there is also a large frost pocket in northern Ingham and Ionia Counties near the center of the subsection.

BEDROCK GEOLOGY: Exposed bedrock is rare; glacial deposits over bedrock are as thick as 350 or 400 feet (Akers 1938). The subsection is underlain primarily by Paleozoic bedrock, primarily Pennsylvanian sandstone, shale, coal, and limestone, with Mississippian shale and gypsum occurring at the western edge (Dorr and Eschman 1984). There are also scattered occurrences of Mesozoic bedrock; these Jurassic red beds consist mainly of sandstone, shale, and clay, with minor beds of limestone and gypsum.

LANDFORMS: Most of the subsection consists of loamy till plain and narrow bands of loamy end moraine (Sub-subsection VI.4.1); the northern edge of the subsection consists of both sandy ground moraine and sandy, steep end moraines (Sub-subsection VI.4.2) and is considered transitional to Subsection VII.2 to the north.

LAKES AND STREAMS: Lakes are more numerous on the sandy moraines of Sub-subsection VI.4.2 than in Sub-subsection VI.4.1. Many streams are present in both sub-subsections.

SOILS: See sub-subsections.

PRESETTLEMENT VEGETATION: See sub-subsections.

NATURAL DISTURBANCE: See sub-subsections.

PRESENT VEGETATION AND LAND USE: See sub-subsections.

RARE PLANT COMMUNITIES: See sub-subsections.

RARE PLANTS: See sub-subsections.

RARE ANIMALS: See sub-subsections.

NATURAL AREAS: See sub-subsections.

PUBLIC LAND MANAGERS: See sub-subsections.

CONSERVATION CONCERNS: See sub-subsections.

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