Northern Prairie Wildlife Research Center
DISCUSSION: The DISCUSSION section provides a brief, general overview of the map unit, concentrating on the most distinctive characteristics of the map unit. In some cases, no DISCUSSION section is provided.
ELEVATION: The elevation is provided in both feet and meters, and is based on 1:24,000 topographic maps in most cases. Elevation can be an important factor for understanding biotic distribution. Elevation can be used to contrast adjacent map units. For example, a sub-subdistrict of lake plain will generally be very flat and poorly drained. A sub-subdistrict of end moraine will have steeper, more irregular topography, characterized by better drainage conditions.
AREA: Area is listed in acres and hectares.
STATES: The states in which the section, subsection, or sub-subsection occurs are listed here.
CLIMATE: Several climatic variables are described, including average annual precipitation, average annual snowfall, average growing season length, and extreme minimum temperature. Other climatic factors may be discussed in certain sections, subsections, or sub-subsections. The influence of specific climatic factors on the biota and land management may also be discussed when appropriate.
BEDROCK GEOLOGY: Predominant or common bedrock types are described, emphasizing the bedrock types closest to the surface. If bedrock is not exposed within the map unit, the depth of overlying glacial deposits is provided, where known. Important mineral deposits of economic importance are mentioned. The detail of bedrock maps differs greatly across the three States; this is reflected in map-unit descriptions.
LANDFORMS: Most of the landforms occurring in Michigan, Minnesota, and Wisconsin are glacial landforms. The major landforms are described, with some discussion of the size of the landform features, as well as the spatial relationship of neighboring landforms.
LAKES AND STREAMS: The number, size, and types of lakes and streams are described. Water chemistry and substrate are also discussed where appropriate. Consistently presented data bases for lakes and streams do not exist for all three states, but such data bases are being developed, and may soon allow for more consistent and detailed descriptions of both.
SOILS: Soils descriptions can include parent material, soil texture, slope class, and drainage class. Factors important for understanding forested landscapes often differ from those used for describing agricultural soils. Characteristic soil orders are listed for each mapping unit.
PRESETTLEMENT VEGETATION: Comments on the presettlement vegetation are based on maps by Marschner (1974) in Minnesota, Finley (1976) in Wisconsin, several published studies describing portions of Michigan, and an ongoing statewide mapping project in Michigan. Presettlement mapping provides a brief view of the vegetation at the time of the original land surveys, before intensive logging, farming, industrial development, and settlement in the 19th century by immigrants from outside of North America. Published maps, used for the descriptions of Minnesota and Wisconsin, provide generalized descriptions of the dominant vegetation, including wetlands, forests, and grasslands. The surveyors' notes, used for many of the Michigan descriptions, provide more detailed information on species composition of forests and natural disturbances.
NATURAL DISTURBANCE: The common natural disturbances that occur across the three-State area are listed and discussed. Many of these were mentioned and mapped by the first land surveyors. Some of the more common disturbances referenced by the surveyors were forest fires, windthrown forests, flooding caused by beaver dams, and alterations of wetlands caused by fluctuations of Great Lakes water levels. Land use by Native Americans, including game management, foot trails, villages, and farming, were also mapped by the first land surveyors. Other natural disturbances that are critical for maintaining the natural biota of ecosystems were not mentioned by the land surveyors, but have been subsequently documented by researchers. Examples of these include widespread disturbance and modification of prairie soils by mammals, such as bison and prairie dogs, and insects, such as ants. Such disturbances are also discussed in this section.
PRESENT VEGETATION AND LAND USE: The full range of vegetation conditions and land uses will be discussed in this section, but not in great detail; obviously there are many more detailed studies of both present vegetation and land use available to the reader. Present vegetation includes natural vegetation, both in relatively intact and highly modified condition, and agricultural and plantation lands.
RARE PLANT COMMUNITIES: This section lists, and in some cases, discusses plant communities that are considered rare, based on scientific literature and the data bases of the Heritage Programs.
RARE PLANTS: This section contains both the common and scientific names of rare plants listed by the Heritage Programs of all three States. Included within this list are species listed as threatened and endangered by the State and Federal Governments, and as special concern by the states. The status of each of these species is periodically reviewed and revised on the basis of available scientific data.
RARE ANIMALS: This section contains both the common and scientific names of rare animals listed by the Heritage Programs of all three States. Included within this list are species listed as threatened and endangered by the State and Federal Governments, and as of special concern by the States. The status of each of these species is periodically reviewed and revised on the basis of available scientific data.
NATURAL AREAS: These lists include both privately and publicly owned natural areas. All three States name and track their natural areas differently. County- and township-owned natural areas are more thoroughly tracked in Minnesota and Wisconsin than in Michigan.
PUBLIC LAND MANAGERS: Public lands are important areas for natural resource management. In this section, major public land ownerships are listed for each mapping unit. This section is based on information from published maps, Heritage Programs, and government agencies.
CONSERVATION CONCERNS: Concerns are based on comments from staff of Heritage Programs, conservation groups, university staff, and government agencies. The lists of concerns are often incomplete and may focus on the concerns of a single agency or organization. This document does not attempt to resolve these concerns.
BOUNDARIES: Boundary interpretations and questions are referenced or discussed here. Alternative interpretations of boundaries typically occur in areas where there has been earlier classification by government agencies. Different interpretations are often the result of mapping and classifying at different scales, especially when previous work has been done at a more local scale or only on lands under a single ownership. It is assumed that further studies may be required to resolve some of the boundary questions discussed here. Different boundaries will often result from studies either based on different data or conducted for different management purposes.