Natural Vegetation of Minnesota at the Time of the Public Land Survey 1847-1907
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Natural Vegetation of Minnesota At the Time of the Public Land Survey 1847-1907 Minnesota Department of Natural Resources _ Biological Report No.1 resettlement Minnesota. topography prevented the spread of fires, and little bluestem and sideoats grama Imagine. " ...rolling prairies ... a dense forest of maple, basswood, and occurred on the thin soils of dry uplands. Pundulation upon undulation as elm developed. Within the coniferous far as the eye can reach ... a view forest biome, fires created a mosaic of Throughout the prairie biome, numerous of peculiar sublimity ..." wrote H.D. forest types from young postfire stands of wetland communities dominated by Ruggles of the western Minnesota aspen-birch and jack pine, to old- sedges and rushes, rather than grasses, landscape in 1835. Early accounts of the growth stands of white and red pine, were interspersed with upland prairie. towering pines in the north abounded spruce-fir, northern white cedar, and The glacial moraine landforms of the with equally vivid impressions. And in maple-basswood-yellow birch forest. prairie region were ideally suited for the south, French explorers extolled the This complex interaction of fire with wetland formation; their hilly knob and vast forests of maple, basswood, and elm, climate, soils, and topography created a kettle-type topography abounded with calling them the "Big Woods." dynamic landscape-a constantly shifting prairie pothole marshes. mosaic of vegetation types. The early European settlers had de Aspen Parkland scribed, in astonished detail, the three The aspen parkland formed an ecotone major biomes that meet in Minnesota: Vegetation Types of the Prairie between the prairie and coniferous forest tallgrass prairie, northern coniferous and Deciduous Forest of extreme northwest Minnesota and forest, and eastern deciduous forest. Upland Prairie and Prairie Wetland Tallgrass prairie, at the time of the public land survey in the l850s, covered one third of the state. It occupied a wide variety of landforms, including beach Dittmer Wildlife Management Area, Mahnomen County adjacent Canada. It covered vast acreages within the poorly drained flatlands left by Glacial Lake Agassiz. Sometimes referred to as brush prairie, the aspen parkland was a fire-maintained The vegetation types that defined these mosaic of wet prairie, sedge meadow, biomes were distributed on the landscape shrub thicket, and aspen groves. according to climate, soil, and landform patterns. Natural disturbances such as Oak Woodland and Brushland fire, severe drought, windstorm, and The oak woodland and brushland was a insect outbreaks modified the vegetation Prairie Coteau Scientific and Natural Area, common ecotonal type between the Pipestone County on a local and regional scale. Of these, prairie and deciduous forest. Fire, more fire was the most important disturbance ridges and swales, glacial lake beds, than landform type or climate, was the agent. morainic hills, steep bluffs, and rolling significant factor influencing the position till plains. Along these landforms, and extent of this community. Frequent fires-started by lightning and important differences occurred in the by Indians for hunting and other pur plants and animals that compose the The oak woodland and brushland 'poses-helped to maintain the species prairie ecosystem. The most striking vegetation type has often been referred to composition and treeless structure of the indicator was the predictable change in as savanna. However, in Minnesota the tallgrass prairie. Where fires were less dominance of a few major prairie grasses. image of a tall grass prairie dotted with frequent or intense, trees invaded the The distribution pattern of these grasses trees to create an orchard-like appearance prairie in scattered groves to form coincided with differences in soil is more myth than fact. Careful study of woodland and parkland communities. moisture levels related to topography. In the original public land survey records This created a vegetational ecotone general, prairie cordgrass and bluejoint has led to a new interpretation. The oak known as the prairie/forest border. dominated the wet lowlands; big woodland and brushland ranged from Within the deciduous forest biome, where bluestem and Indian grass occupied the small groves of trees intermixed with firebreaks such as rivers, lakes, and rough deep fertile soils of the moist uplands; open prairie to a chaparral-like commu- original public land survey covered over relatively rare in the state. It was 3,000 square miles in the south-central generally restricted to rich, morainic soils part of the state. The early settlers called where fire frequencies were low. The this area the "Big Woods." Smaller areas most conspicuous area of northern of maple-basswood occurred in the hardwoods was the narrow belt along the rugged, stream-dissected lands of North Shore Highlands that stretches southeastern Minnesota and in the west from Duluth to the Canadian border. It central part of the state. The boundaries was also found in fire-protected pockets of this forest were in large part controlled across north-central Minnesota, as far by the frequency of fire . The dominant west as Cass Lake. Cedar Creek Natural History Area, Anoka County Great Lakes Pine Forest The Great Lakes pine forest occurs in nity of scrub forest and dense shrub Minnesota primarily on thin glacial till thicket. The structure of the community was largely determined by soil conditions and fire frequency. The oaks, especially bur oak and northern pin oak, were the dominant trees. In the southeast, white oak and black oak were also common. Floodplain Forest Floodplain forests occupy both major and minor water courses throughout the state. Wolsfeld Woods Scientific and Natural They are especially well developed in the Area, Hennepin County valleys of the Mississippi, Minnesota, and Red rivers. The lowland sites trees are highly fire-sensitive and were occupied by these forests are subjected to restricted to areas where natural fire periodic flood and drought. Spring breaks such as rivers, lakes, and rough topography prevented the spread of fire Boundary Waters Canoe Area, Cook County from the adjacent prairie lands. over bedrock in the Canadian-Minnesota border lakes area and in the gravelly Vegetation Types moraines and sandy outwash plains in the north-central part of the state. This forest of the Conifer Forest is defined by its characteristic trees eastern white pine and red pine. Northern Hardwood Forest In Minnesota, the northern hardwood Historically, tree composition and age forest is dominated by sugar maple, structure of the pine forest were largely basswood, yellow birch, and red oak. determined by natural fire cycles. Fires Conifers, particularly white pine, of varying frequency and intensity northern white cedar, and balsam fir are created a dynamic ecosystem composed SI. Croix River, Chisago County often found scattered through the forest. of early postfire stands of jack pine and Due to the fire-sensitivity of the domi red pine and mature old-growth stands of nant trees, this forest association was floodwaters enrich the soil as they white pine. In general, red pine was deposit silt over the forest floor. Silver more abundant than white pine and maple, American elm, green ash, black occurred on coarsely-textured, dry sites willow, and cottonwood are the dominant prone to fires. White pine stands trees and poison ivy and stinging nettle occurred on the mesic sites of lake -the characteristic understory plants. margins and lower slopes less subject to fires. Maple-Basswood Forest Minnesota's maple-basswood forests, Jack Pine Forest dominated by elm, basswood, sugar This forest community occurs on the maple, and red oak, occur at the western driest, least fertile soils of the pine edge of the deciduous forest biome of region. It is especially prevalent on eastern North America. The largest sandy outwash plains in north-central continuous area of maple-basswood Minnesota and on bedrock outcrops north forest in Minnesota at the time of the Tettegouche State Park, Lake County of Lake Superior. Jack pine grows in sota-a region characterized by a short, contrast, fens and swamps develop on moist growing season and deep snow. mildly acid to highly alkaline peat The dominant tree species, balsam fir, deposits affected by mineral-rich ground white spruce, black spruce, trembling water. Fens are composed of grasses and aspen, and white birch occur in pure or sedges, while swamps are dominated by mixed stands. woody plants-either coniferous trees (e.g., northern white cedar) or deciduous Species composition varies considerably trees (e.g., black ash). in response to differences in site condi tions and natural fire cycles. Balsam fir, Changes in the Natural owing to its great shade tolerance, tends Vegetation Since Settlement to form extensive stands in the absence of frequent fires. Natural disturbances, After more than a century of European including fire, wind, and spruce budworm settlement, nearly all the natural commu epidemics often result in extensive areas nities composing the three major biomes of even-aged stands of spruce-fir or have been substantially altered. The vast aspen-birch forest. Far less extensive, tallgrass prairie that once covered one Boundary Waters Canoe Area, Lake County and found mainly in extreme northeast third of the state has been reduced to less pure stands or in mixtures with aspen, Minnesota, old-growth white cedar than one percent of its original expanse. northern red oak, and red pine. Most forests occur on fire-protected uplands. The largest continuous area of climax natural stands originate following fire. deciduous forest-the "Big Woods"-is Fire opens the habitat to direct sunlight Peatland now restricted to small, scattered islands and exposes a mineral soil seedbed-both Extensive peatlands blanket the nearly of forest surrounded by cropland. The requirements for jack pine reproduction. flat landscape left when the waters great stands of virgin pine that once The dry, open conditions under the jack drained from the ancient glacial lakes of defined the North Woods have been pine canopy allow for a variety of north-central Minnesota.