Ecoregions of Wisconsin (EPA)
Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources; they are designed to serve as a spatial framework for the research, assessment, monitoring, and management of ecosystems and ecosystem components. Special purpose maps of characteristics such as plant communities, water quality, soils, and fish distributions are necessary and have long been used for dealing with specific research and management problems. Ecoregions, on the other hand, portray areas within which there is similarity in the mosaic of all biotic and abiotic components of both terrestrial and aquatic ecosystems. Recognition, identification, and delineation of these multipurpose regions are critical for structuring and implementing integrated management strategies across federal, state, tribal, and local governmental agencies that are responsible for different types of resources within the same geographical areas.
The naming of level III and level IV ecoregions was intended to associate place names with a key landscape characteristic descriptive or unique to the region. Consequently, the ecoregion names (and the map) serve an educational purpose by relating public perceptions to the environment, thus playing on the concept of "place" and allowing a connection to be made between ecoregions and the general public.
47. Western Corn Belt Plains
Once covered with tall-grass prairie, over 75 percent of the Western Corn Belt Plains is now used for cropland agriculture, and much of the remainder is in forage for livestock. A combination of nearly level to gently rolling till plains and hilly loess plains, an average annual precipitation of 63–89 cm, which occurs mainly in the growing season, and fertile, warm, moist soils make this one of the most productive areas of corn and soybeans in the world. Surface and groundwater contamination from fertilizer and pesticide applications as well as livestock concentrations are a major concern for this ecoregion. The northeastern corner of the Western Corn Belt Plains (47) is a loess-covered till plain and extends into a small area in western Wisconsin and borders the northern boundary of the Driftless Area (52). The fertile prairie soils and gentle topography of this area contribute to more intensive agriculture than in the adjacent North Central Hardwood Forests (51) and Driftless Area (52) ecoregions.
47g. Prairie Pothole Region
The Prairie Pothole Region (47g) is characterized by smooth to undulating topography, productive prairie soils, and loess- and till-capped dolomite bedrock. The potential natural vegetation (PNV) is predominantly tall grass prairie with a gradual transition eastward to more mixed hardwoods, distinguishing 47g from the greater concentration of mixed hardwoods of both 51a to the north and 51b to the east, and the mixed prairie and oak savanna of 52b to the south.
50. Northern Lakes and Forests
The Northern Lakes and Forests (50) is an ecoregion of relatively nutrient poor glacial soils, coniferous and northern hardwoods forests, undulating till plains, morainal hills, broad lacustrine basins, and areas of extensive sandy outwash plains. Soils are formed primarily from sandy and loamy glacial drift material and generally lack the arability of those in adjacent ecoregions to the south. Ecoregion 50 also has lower annual temperatures and a frost-free period that is
considerably shorter than other ecoregions in Wisconsin. These conditions generally hinder agriculture; therefore, woodland and forest are the predominant land use/land cover. The numerous lakes that dot the landscape are clearer, at a lower trophic state (mostly oligotrophic to mesotrophic with few eutrophic lakes), and less productive than those in ecoregions to the south. Streams of ecoregion 50 are mostly perennial, originating in lakes and wetlands; however, stream density is relatively low compared to ecoregions to the south. The Northern Lakes and Forests region is the only ecoregion in Wisconsin where acid sensitive lakes are found. Portions of the southern boundary of ecoregion 50 roughly correspond to the southernmost extent of lakes with alkalinity values less than 400 meq/l (Omernik and Griffith 1986).
50a. Lake Superior Clay Plain
The Lake Superior Clay Plain (50a) is a flat to undulating lake plain and outwash lowland. The soils of 50a are generally calcareous red clays with organic deposits in swampy areas. A dearth of lakes, along with a somewhat milder climate and longer growing season due to the climate amelioration by Lake Superior, differentiates 50a from surrounding ecoregions. Land use in 50a is predominantly woodland with some limited agriculture of hay, small grains, and apples on Bayfield Peninsula, distinguishing 50a from most other level IV ecoregions in Northern Lakes and Forests (50) where the land use/land cover is predominantly forest and woodland. Ecoregion 50a has a PNV of boreal forest (although somewhat different than boreal forests to the north), unlike the pine barrens and pine forests of 50c, the mosaic of pine and birch in 50b, and the northern mesic forest of 50e.
50b. Minnesota/Wisconsin Upland Till Plain
The Minnesota/Wisconsin Upland Till Plain (50b) is an undulating stagnation and ground moraine plain, with broad areas of hummocky, acid, loamy and sandy till and outwash. Ecoregion 50b has fewer lakes than ecoregions to the east, but a greater lake density than ecoregion 50a to the north. Extensive wetlands--in areas of poorly drained soils, peat over acid sedge and woody peat soils--are scattered throughout the ecoregion and are common in hummocky areas. The till plain of 50b supports a PNV mosaic of red and white pine, conifer swamps, and aspen/white birch/pine forests. Woodland and forest cover the majority of the ecoregion, although there is some limited agriculture with main crops of feed-grains and potatoes. This region also has one of the lowest densities of roads in the state.
50c. St. Croix Pine Barrens
The St. Croix Pine Barrens (50c) ecoregion is characterized by jack pine, concentrations of red and white pine forests and barrens, and well-drained, pink sandy soils. Ecoregion 50c has a greater concentration of lakes, a higher percentage of clear lakes, and lakes with a lower trophic state than in surrounding ecoregions. The sandy soils and pine barren vegetation distinguishes ecoregion 50c from the silty lake plain and boreal forests of 50a and the till plain and more deciduous forest mosaic of 50b.
50d. Ontonagon Lobe Moraines and Gogebic Iron Range
The rolling to hilly, bedrock-controlled and collapsed moraines consisting of loamy till, much of it shallow over igneous and metamorphic rock, distinguish the Ontonagon Lobe Moraines and Gogebic Iron Range (50d) ecoregion from surrounding regions. Rock outcrops increase from very few in the southern portion of this ecoregion to abundant in the north. Likewise, the topography changes from rolling in the southern portion to hilly in the north. Perennial streams are common, and there are fewer lakes than in ecoregions to the south, but more than adjacent ecoregion 50a. The PNV of 50d is a mosaic of hemlock/sugar-maple/pine forests, swamp conifers, and cedar/hemlock forests. This represents a transition from the boreal forests of ecoregion 50a to the mix of hardwoods and conifer forests of ecoregion 50e. Historic mining of iron and copper occurred along the northern and northwestern edge of this region.
50e. Chequamegon Moraine and Outwash Plain
Irregular plains and stagnation moraines, broad areas of hummocky topography, pitted glacial outwash, numerous kettle lakes, and abundant swamps and bogs characterize the Chequamegon Moraine and Outwash Plain (50e) ecoregion. This region has more poorly developed drainage than ecoregions to the west. The soils are coarse, acid, loamy, and sandy-loam mixed--different from the pink sandy soils of ecoregion 50c and the more rocky and silty soils of ecoregion 50g.
50f. Blue Hills
The Blue Hills (50f) ecoregion has greater relief and a higher concentration of lakes than most surrounding ecoregions, and it contains lakes with generally lower trophic states than those of adjacent ecoregions to the east, south, and southwest. End moraines, hummocky hills and depressions, along with areas of Precambrian intrusives are common to 50f as compared to the predominantly rocky ground moraines in 50g to the east. Periodic outcrops of pink quartzite have influenced the topography of the region. Ecoregion 50f supports a PNV of hemlock/sugar maple/yellow birch, white pine and red pine forests, a transition from predominantly hemlock/sugar maple/pine forests of ecoregions in the east to sugar-maple/basswood/oak forests, oak forests, and prairie vegetation of ecoregion 51 to the west.
50g. Chippewa Lobe Rocky Ground Moraines
Much of the Chippewa Lobe Rocky Ground Moraines (50g) ecoregion is comprised of productive but rocky soils, scattered wetlands, extensive eskers and drumlins, and outwash plains. Ecoregion 50g has a considerably lower density of lakes that generally have higher trophic states than 50e, 50f, 50i, and 50h. The rocky soils of 50g are a contrast with the well-drained loamy soils in 50f and the sandy soils in 50i. Ecoregion 50g also supports a PNV mosaic of northern mesic forest (hemlock/sugar maple/yellow birch/white and red pine) and wetland vegetation (swamp conifers/white cedar/black spruce), compared to the predominantly red and white pine forest of ecoregion 50i and the lower hemlock component of forests in ecoregions 50f and 50h.
50h. Perkinstown End Moraine
The Perkinstown End Moraine (50h) ecoregion is characterized by hilly to rolling collapsed moraines with outwash sand and gravel and Precambrian intrusive rocks. Relief in this ecoregion is greater than in surrounding regions. The soils of 50h are coarse, loamy, and moderate to well drained, over till, in contrast to the more rocky and poorly drained soils of 50g to the south. In addition, ecoregion 50h has fewer lakes than adjacent level IV ecoregions in the Northern Lakes and Forests (50).
50i. Northern Highlands Lakes Country
The Northern Highlands Lakes Country (50i) is distinguished from surrounding ecoregions by pitted outwash, extensive glacial lakes (many of which are shallow), and wetlands. In contrast to other ecoregions in the Northern Lakes and Forests (50) ecoregion, 50i contains a higher density of lakes of generally lower trophic state and lower alkalinity values (hence, greater sensitivity to acidification). The region's soils developed in deep, acidic drift are gravelly, sandy, and well to excessively drained. Unlike the predominantly hardwood forests of surrounding ecoregions, 50i supports a PNV of white and red pine forests, some pine barrens, and jack pine to the south.
50j. Brule and Paint Rivers Drumlins
The Brule and Paint Rivers Drumlins (50j) ecoregion has extensive eskers and drumlinized ground moraines, pitted and unpitted outwash, wetlands, large glacial lakes, and a lower density of lakes than in adjacent ecoregion 50i. Lake trophic state is low, with a higher percentage of oligotrophic and mesotrophic lakes than most Level IV ecoregions in the Northern Lakes and Forests (50). Soils of the region range from fine to coarse, poor to well drained, and loamy and silty with extensive organic deposits, differing from the sandy, more acid soils in adjacent ecoregions. The PNV is sugar-maple/basswood forest and hemlock/sugar-maple forest, as compared to the more coniferous forests of 50i and the pine and oak barrens of 50k.
50k. Wisconsin/Michigan Pine and Oak Barrens
Irregular outwash plains and moraines, sandy and sandy-loam soils over outwash, sandy and loamy till, and peat deposits in depressions characterize the Wisconsin/Michigan Pine and Oak Barrens (50k) ecoregion. The features are a contrast to the extensive eskers and drumlins, and more loamy and silty soils of adjacent ecoregion 50j. Also, unlike the hardwood forests of ecoregion 50j to the west, 50k supports a PNV of white/red pine forests, jack pine forests, and oak forests and barrens. Land use in 50k is predominantly woodland, although some mixed agriculture is found. More frost-free days occur in 50k than in adjacent eastern ecoregions, due to the ameliorating effect of Lake Michigan and Green Bay, contributing to the greater agricultural component of the land cover/land use. In addition, 50k has more shallow bedrock than surrounding regions, with areas of exposed Precambrian basalt and granite.
50l. Menominee Ground Moraine
The Menominee Ground Moraine (50l) ecoregion contains an undulating ground moraine with drumlins and swamps. The uplands consists of loamy soil over calcareous loamy till (some over dolomite); the lowland areas are muck. The region is dominantly woodland and woodland swamp, but there is a significant agricultural presence. PNV of the region is beech/sugar maple/hemlock and swamp conifer, a contrast to the white/red pine, jack pine, and oak forests of neighboring 50k.
51. North Central Hardwood Forests
The North Central Hardwoods Forests (51) ecoregion is transitional between the predominantly forested Northern Lakes and Forests (50) and the agricultural ecoregions to the south. Nearly level to rolling till plains, lacustrine basins, outwash plains, and rolling to hilly moraines comprise the physiography of this region. The land use/land cover in this ecoregion consists of a mosaic of forests, wetlands and lakes, cropland agriculture, pasture, and dairy operations. The growing season is generally longer and warmer than that of ecoregion 50 to the north, and the soils are more arable and fertile, contributing to the greater agricultural component of the land use. Lake densities are generally lower here than in the Northern Lakes and Forests, and lake trophic states tend to be higher, with higher percentages in eutrophic and hypereutrophic classes. Stream density is highly variable, with some areas having virtually no streams--in wetland and kettle terrain--to others with high densities of perennial streams.
51a. St. Croix Pitted Stagnation Moraines
The St. Croix Pitted Stagnation Moraines (51a) is a region of ground and stagnation moraines with broad irregular areas of hummocky topography. Soils are silty and loamy, with sandy loamy till commonly underlain by a substratum of acid sand and gravel glacial outwash. There are more lakes in 51a than in ecoregions to the east and south, and lake trophic states, although generally higher than in the region to the north, are lower than in the bordering ecoregion to the southeast. Land use in this region is a mix of agriculture and woodland, in contrast to the mostly woodland and forest land cover of ecoregions to the north and the greater amounts of agriculture in ecoregions to the southeast. The PNV of 51a includes aspen/birch/pine forests, oak-maple forests, and sugar-maple/birch/pine forests, representing a transition from the pines of 50b to the tall grass prairie and oak forests of 47g.
51b. Central Wisconsin Undulating Till Plain
The Central Wisconsin Undulating Till Plain (51b) ecoregion has a greater percentage of agricultural land use than adjacent ecoregion 51a. The land cover mosaic of woodland and agriculture includes large areas of cropland that produce silage corn, oats, barley, and some apples. Ecoregion 51b has fewer lakes, with higher trophic states, than adjacent level IV ecoregions in ecoregion 51. The undulating to rolling irregular plains of sandy loam till and outwash sands also distinguish this ecoregion from the stagnation moraines of ecoregion 51a to the west and the lacustrine sand plains of ecoregion 51c to the south. This ecoregion has areas in the far east that are underlain with igneous metamorphic rock outcrops, and areas in the west and southwest that are underlain by sandstone and shale. Outcrops of sandstone comprise roughly 70% of the total area of the ecoregion. The region supports a transitional PNV mosaic of oak, hemlock/sugar maple/yellow birch, and white pine/red pine forests in the north, and more sugar maple/basswood/ oak forests to the south.
51c. Glacial Lake Wisconsin Sand Plain
Compared to adjacent ecoregions, the Glacial Lake Wisconsin Sand Plain (51c) is an area of low relief. The droughty outwash, lacustrine and slope wash sands, sand buttes, and stream bottom and wetland soils support a PNV of jack pine/scrub-oak forests and barrens, along with sedge meadows and conifer swamps, which characterize this flat sandy lake plain. This PNV is in contrast to the predominantly white and black oak vegetation of ecoregion 51d. The region is also distinguished by its more extensive wetlands and a lack of natural lakes. Most of the existing lakes have been constructed for use in cranberry production. Land use in this region consists of woodland and agriculture, with crops including cranberries, strawberries, and potatoes.
51d. Central Sand Ridges
The Central Sand Ridges (51d) ecoregion has the highest density of lakes with the lowest trophic states of all level IV ecoregions in the North Central Hardwood Forests (51). Pitted glacial outwash with extensive eskers and drumlins, ice contact deposits, rolling ground moraines, and steep end moraines distinguish this region from the flat lake plain of adjacent ecoregion 51c. The dry, sandy, and loamy till soils of the region support a PNV of oak savanna (white oak, black oak, and bur oak) with areas of sedge meadows, unlike the wetland vegetation and pine or oak barrens of ecoregion 51c and the mosaic of hemlock/beech/maple forests and mixed conifers of ecoregion 51e to the north.
51e. Upper Wolf River Stagnation Moraine
The Upper Wolf River Stagnation Moraine (51e) ecoregion is characterized by the hummocky ground and end moraines and pitted outwash, in contrast to the level till plains of ecoregion 51f to the east and the irregular till plain of ecoregion 51b to the west. This region supports a PNV mosaic of hemlock/beech/sugar-maple, wetland vegetation, and mixed conifers, as compared to the predominantly oak forests of 51d to the south. Land use in 51e is mixed agriculture/woodland with a larger area of extensive forest than adjacent level IV ecoregions in the North Central Hardwoods Forests (51). This is due to land use practices within the Menominee Indian Reservation; more forest cover is still intact, and agricultural practices are less significant. The lake trophic state in 51e is generally higher than in 51d to the south.
51f. Green Bay Till and Lacustrine Plain
Green Bay Till and Lacustrine Plain (51f) is a transitional ecoregion characterized by wetlands, a mix of outwash and loamy recessional moraines, with many areas of outwash plains in the northwest, lake plains and ground moraines in the south, and ground moraines throughout the rest of the region. The PNV of the region represents a shift from the predominantly northern hardwoods and conifer swamps along the lake shore to the maple/basswood/oak forests and oak savanna to the south. The red sandy, loamy soils of this ecoregion are similar to some southern areas in the northern Wisconsin/Michigan Pine Barrens (50k); however, due to the generally milder climate (because of proximity to Lake Michigan), the growing season is more favorable and much of the area has been cleared of natural vegetation and replaced by agriculture.
51g. Door Peninsula
The Door Peninsula (51g) ecoregion is a lakeshore region with ground moraines. The longer growing season and shallow, fertile, calcareous loamy till soils of this ecoregion support a mixed woodland/agriculture land use. Orchard and fruit crops, such as apples and cherries, are common. The bedrock geology of 51g is shallower than other ecoregions in 51 and consists primarily of Silurian dolomite bedrock. In recent years, this region has become popular for tourism.
52. Driftless Area
The hilly uplands of the Driftless Area (52) ecoregion easily distinguish it from surrounding ecoregions. Much of the area consists of a deeply dissected loess-capped plateau. Also called the Paleozoic Plateau because there is evidence of glacial drift in this region, the glacial deposits have done little to affect the landscape compared to the subduing influences in adjacent ecoregions. Livestock and dairy farming are major land uses and have had a major impact on stream quality. In contrast to the adjacent glaciated ecoregions, the Driftless Area has few lakes, most of which are reservoirs with generally high trophic states, and a stream density and flow that is generally greater than regions to the east.
52a. Savanna Section
Topography in the Savanna Section (52a) of the Driftless Area is different than the rest of the level III ecoregion because of its characteristic broad, relatively level ridge tops and narrow steep sided valley bottoms. Elsewhere in the dissected Driftless Area, the landform mosaic comprises relatively broad, flat valley bottoms with steep sharper crested ridges or a pattern of nearly equal amounts of flatter areas in the valley bottoms and interfluves. The soils are well drained silty loess over residuum, dolostone, limestone, or sandstone. Land use patterns in the Driftless Area also follow spatial differences in slope; hence, 52a is predominantly agriculture on the uplands and some mixed woodland/agriculture in lowland areas. The PNV of the region is a mosaic of oak forests and savannas, large prairie grassland areas, and some sugar maple/basswood/oak forests. The region is also known for past lead and zinc mining.
52b. Coulee Section
Dissected slopes and open hills with most of the gentle slope on the lowland characterize the Coulee Section (52b) ecoregion. Soils are well drained silty loess over residuum, limestone, sandstone or shale, with soils over quartzite in the Baraboo Hills area. Land use in the region is predominantly mixed agriculture/woodland, with most of the griculture occurring on the lowlands and more level hilltops. The PNV of ecoregion 52b is a mosaic of oak forests and prairie, with larger areas of sugar maple/basswood/oak forests than in 52a.
53. Southeastern Wisconsin Till Plains
The Southeastern Wisconsin Till Plains (53) ecoregion supports a mosaic of vegetation types and represents a transition between the hardwood forests and oak savannas of the ecoregions to the west and the tall-grass prairies of the Central Corn Belt Plains (54) to the south. Similar to the Corn Belt Plains (54) ecoregion, land use in the Southeastern Wisconsin Till Plains (53) is mostly cropland, but the crops historically have been largely forage and feed grains to support dairy operations, rather than corn and soybeans for cash crops. The ecoregion has a higher plant hardiness value than ecoregions to the north and west, a different mosaic of soils than western ecoregions, and flatter topography. There are fewer lakes here than in ecoregions to the north, but considerably more than in the western Driftless Area (52) and the southern Central Corn Belt Plains (47). The region also has a relatively high diversity of aquatic species.
53a. Rock River Drift Plain
The Rock River Drift Plain (53a) ecoregion has a greater stream density and fewer lakes than in ecoregions to the north and east. Glaciation of this region is older, late Pliocene-early Pleistocene, than in surrounding ecoregions. The drift mantle is thin and deeply weathered, with leached soils developed from a silt-loam cap of loess over glacial drift. Steeper topography and broad outwash plains with loamy and sandy soils also characterize this region.
53b. Kettle Moraines
The Kettle Moraines (53b) ecoregion contains a higher concentration of lakes with lower trophic states than in the rest of the Southeastern Wisconsin Till Plains (53). The soils are clayey to the east, especially along the Lake Michigan shore, and more sandy to the west, but generally less clayey than the soils in ecoregion 53d to the north. The region also contains extensive ground and end moraines and pitted outwash with belts of hilly moraines. It generally has greater relief than ecoregion 53d to the northeast.
53c. Southeastern Wisconsin Savanna and Till Plain
The till plains of the Southeastern Wisconsin Savanna and Till Plain (53c) ecoregion support a mix of agriculture (cropland and dairy operations) and woodland. Crops include forage crops to support the dairy operations and a wide range of truck and specialty crops. Most of the original vegetation has been cleared, with forested areas remaining only on steeper end moraines and poorly drained depressions. Irregular till plains, end moraines, kettles, and drumlins are common, and wetlands are found throughout the region, especially along end morainal ridges. PNV of this region is transitional with a mosaic of sugar maple, basswood, oak to the east, and an increasing amount of white, black, and bur oak, oak savanna, prairie, and sedge meadows toward the west.
53d. Lake Michigan Lacustrine Clay Plain
The Lake Michigan Lacustrine Clay Plain (53d) ecoregion is characterized by red calcareous clay soil, lacustrine and till deposits, and a flat plain. The topography is flatter than ecoregions to the south, and there are fewer lakes, but the lakes have generally higher trophic states than in adjacent level IV ecoregions in 50 and 51. Soils are generally silty and loamy over calcareous loamy till, with muck and loamy lacustrine soils in low-lying areas. Ecoregion 53d has prime farmland with a longer growing season and more fertile soils than surrounding ecoregions. Agriculture has a different mix of crops, with more fruits and vegetables, than that of ecoregion 53c. The PNV of this region is beech/sugar maple/basswood/red and white oak forests with a greater concentration of beech than other ecoregions in 53.
54. Central Corn Belt Plains
Prairie communities were native to the glaciated Central Corn Belt Plains, and they were a stark contrast to the hardwood forests that grew on the drift plains of ecoregions to the east. Beginning in the nineteenth century, the natural vegetation was gradually replaced by agriculture. Farms are now extensive on the dark, fertile soils of the Central Corn Belt Plains 54, producing corn and soybeans, cattle, sheep, poultry, and especially hogs. However, livestock operations are not as dominant as in the drier Western Corn Belt Plains to the west. Agriculture has affected stream chemistry, turbidity, and habitat. The extent of the Central Corn Belt Plains (54) ecoregion in Wisconsin is contained in a small area in the southeastern portion of the state. Land use of the ecoregion continues to change, from exclusively agriculture to a pattern with an increasing amount of urban and industrial land.
54e. Chiwaukee Prairie Region
The Chiwaukee Prairie Region (54e) is characterized by intensive agriculture, prairie soils, loess capped loamy till, and lacustrine deposits. The soils of ecoregion 54e are fertile and generally more productive than those of ecoregion 53 to the north and west. The PNV of the Chiwaukee Prairie Region is predominantly tall-grass prairie, in contrast to the southern mesic forest and oak savanna of the adjacent region to the north and west. Most of the natural prairie vegetation of ecoregion 54e has been replaced with cropland or urban and industrial land cover.
An explanation of how and why the map of Ecoregions of Wisconsin was compiled and a list of sources can be found in Omernik, J.M., S.S. Chapman, R.A. Lillie, and R.T. Dumke. 2000. Ecoregions of Wisconsin. Transactions of the Wisconsin Acadeny of Sciences, Arts, and Letters. 88:77-103