Regional Landscape Ecosystems of Michigan, Minnesota, and Wisconsin
SUB-SUBSECTION X.5.1. Itasca, Alexandria, and St. Croix Moraines
DISCUSSION: The sandy moraines of this sub-subsection are surrounded by pitted outwash plains with excessively drained soils. As a result, the vegetation on the moraines was subject to regularly recurring fires that originated on the outwash plains, and it was dominated by either upland conifers or aspen-paper birch forest.
ELEVATION: 1,100 to 1,890 feet (335 to 576 m).
AREA: 3,632 square miles (9,391 sq km).
STATES: Minnesota.
CLIMATE: See subsection.
BEDROCK: See subsection.
LANDFORM: Common landforms are stagnation or end moraines, but ground moraine with drumlins is included at the southern margin of the sub-subsection. Moraines are cut by narrow, steep outwash channels, buried channels, and tunnel valleys (Hobbs and Goebel 1982).
LAKES AND STREAMS: Kettle lakes are common on the southwestern part of the Itasca moraine and also in the northern part of the St. Croix moraine. The buried channels and tunnel valleys are often occupied by small kettle lakes and potholes.
SOILS: Most of the soils are sandy loams derived from sandy loam to loam till; gravelly till is also present (University of Minnesota et al. 1969, 1980a). Soils are classified as Boralfs (Anderson and Grigal 1984).
PRESETTLEMENT FOREST: Red pine-white pine forests, along with trembling aspen-paper birch forests, occupied the rolling to irregularly sloped end moraines. Mixed hardwood-pine forest, dominated by a diverse mix of northern hardwoods and white pine, were found in the most fire-protected areas at the eastern edges of the sub-subsection, where fire protection was provided by irregular topography, broad wetlands, and relatively large lakes. Immediately downwind from the outwash plains of Sub-subsection X.5.2, white pine-red pine forests or aspen-birch forests were probably the result of frequent fires that originated on the outwash.
NATURAL DISTURBANCE: Fire was the most prevalent form of disturbance, recurring every 10 to 40 years (Frissell 1973). Windthrow was probably more prevalent in the hardwood-pine forests.
PRESENT VEGETATION AND LAND USE: Present forests contain much more paper birch and trembling aspen than the original forests.
RARE PLANT COMMUNITIES:
RARE PLANTS: Malaxis paludosa (bog adder's-mouth).
RARE ANIMALS: See subsection.
NATURAL AREAS: See subsection.
PUBLIC LAND MANAGERS: See subsection.
CONSERVATION CONCERNS: See subsection.
Previous Section -- Subsection X.5. Pine Moraines and Outwash Plains
Return to Contents
Next Section -- Sub-subsection X.5.2. Park Rapids-Staples and Crow Wing Outwash Plains
