Upper Midwest forest-savanna transition
Encyclopedia
The Upper Midwest forest-savanna transition is a terrestrial ecoregion that is defined by the World Wildlife Fund. An oak savanna
plant community located in the Upper Midwest
region of the United States
, it is a transitory ecotone
between the tallgrass prairie
s to the west and the temperate deciduous forest
s to the east. A part of the Upper Mississippi River basin
, it is considered endangered with less than 5% of the original ecosystem remaining intact, due mostly to overgrazing
and conversion to agriculture
.
has been the primary driver and determinant of the forest dynamics
in the plant community. Due to this the resulting canopy structure has been relatively sparse (the basal area
ranges approximately from 4 to 29 meters hectare
−1). Presence and biodiversity
of plant species is largely controlled by the frequency of fire. Typical tallgrass prairie vegetation such as grass
es, forb
s, shrub
s, and sedges
, increase with an increase in the amount of fire, whereas tree density and basal area decreases.
After European American
settlement
and the abandonment of fire as a land management regime, most savannas have been converted into closed canopy
woodland
s, with shade tolerant
and fire-intolerant
species dominating rather than the historic primary
and secondary succession
species dependent on fire.
, none of the present habitat falls under the designation of National Forests
but comes under the administration of the states' Department of Natural Resources
s or federal entities such as the Fish and Wildlife Service
. Remaining intact habitat areas include:
Oak savanna
An oak savanna is a type of savanna, or lightly forested grassland, where oaks are the dominant tree species. These savannas were maintained historically through wildfires set by lightning, grazing, low precipitation, poor soil, and/or fires set by Native Americans...
plant community located in the Upper Midwest
Upper Midwest
The Upper Midwest is a region in the northern portion of the U.S. Census Bureau's Midwestern United States. It is largely a sub-region of the midwest. Although there are no uniformly agreed-upon boundaries, the region is most commonly used to refer to the states of Minnesota, Wisconsin, and...
region of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, it is a transitory ecotone
Ecotone
An ecotone is a transition area between two biomes but different patches of the landscape, such as forest and grassland. It may be narrow or wide, and it may be local or regional...
between the tallgrass prairie
Tallgrass prairie
The tallgrass prairie is an ecosystem native to central North America, with fire as its primary periodic disturbance. In the past, tallgrass prairies covered a large portion of the American Midwest, just east of the Great Plains, and portions of the Canadian Prairies. They flourished in areas with...
s to the west and the temperate deciduous forest
Temperate deciduous forest
A temperate deciduous forest, more precisely termed temperate broadleaf forest or temperate broadleaved forest, is a biome found in North America, southern South America, Europe, and Asia. A temperate deciduous forest consists of trees that lose their leaves every year...
s to the east. A part of the Upper Mississippi River basin
Upper Mississippi River
The Upper Mississippi River is the portion of the Mississippi River upstream of Cairo, Illinois, United States. From the headwaters at Lake Itasca, Minnesota, the river flows approximately 2000 kilometers to Cairo, where it is joined by the Ohio River to form the Lower Mississippi...
, it is considered endangered with less than 5% of the original ecosystem remaining intact, due mostly to overgrazing
Overgrazing
Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, or by overpopulations of native or non-native wild animals.Overgrazing reduces the...
and conversion to agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
.
Fire and disturbance
Historically, wildfireWildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
has been the primary driver and determinant of the forest dynamics
Forest dynamics
Forest dynamics describes the underlying physical and biological forces that shape and change a forest. That is, the continuous state of change that alters the composition and structure of a forest....
in the plant community. Due to this the resulting canopy structure has been relatively sparse (the basal area
Basal area
Basal area is the term used in forest management that defines the cross-sectional area of a tree at DBH, inside the bark.In most countries, this is usually a measurement taken at a specimen's breast height above the ground and includes the entire diameter of every tree, including the bark...
ranges approximately from 4 to 29 meters hectare
Hectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
−1). Presence and biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
of plant species is largely controlled by the frequency of fire. Typical tallgrass prairie vegetation such as grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
es, forb
Forb
A forb is a herbaceous flowering plant that is not a graminoid . The term is used in biology and in vegetation ecology, especially in relation to grasslands and understory.-Etymology:...
s, shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s, and sedges
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
, increase with an increase in the amount of fire, whereas tree density and basal area decreases.
After European American
European American
A European American is a citizen or resident of the United States who has origins in any of the original peoples of Europe...
settlement
European colonization of the Americas
The start of the European colonization of the Americas is typically dated to 1492. The first Europeans to reach the Americas were the Vikings during the 11th century, who established several colonies in Greenland and one short-lived settlement in present day Newfoundland...
and the abandonment of fire as a land management regime, most savannas have been converted into closed canopy
Crown (botany)
The crown of a plant refers to the totality of the plant's aboveground parts, including stems, leaves, and reproductive structures. A plant canopy consists of one or more plant crowns growing in a given area....
woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
s, with shade tolerant
Shade tolerance
In ecology, shade tolerance is a plant's abilities to tolerate low light levels. The term is also used in horticulture and landscaping, although in this context its use is sometimes sloppy, especially with respect to labeling of plants for sale in nurseries....
and fire-intolerant
Fire ecology
Fire ecology is concerned with the processes linking the natural incidence of fire in an ecosystem and the ecological effects of this fire. Many ecosystems, such as the North American prairie and chaparral ecosystems, and the South African savanna, have evolved with fire as a natural and necessary...
species dominating rather than the historic primary
Pioneer species
Pioneer species are species which colonize previously uncolonized land, usually leading to ecological succession. They are the first organisms to start the chain of events leading to a livable biosphere or ecosystem...
and secondary succession
Secondary succession
Secondary succession is one of the two types of ecological succession of plant life. As opposed to the first, primary succession, secondary succession is a process started by an event that reduces an already established ecosystem Secondary succession is one of the two types of ecological...
species dependent on fire.
Species distribution
Trees:- Quercus macrocarpa (Bur oak)
- Tilia americanaTilia americanaTilia americana is a species of Tilia native to eastern North America, from southeast Manitoba east to New Brunswick, southwest to northeast Texas, and southeast to South Carolina, and west along the Niobrara River to Cherry County, Nebraska...
(American basswood) - Acer saccharum (Sugar maple)
- Quercus rubra (Red oak)
Intact habitat
A survey in 1985 concluded that only 26 square kilometre of intact habitat remain, roughly 0.02% of what is estimated to have existed at the time of European settlement. Highly dispersed and fragmentedHabitat fragmentation
Habitat fragmentation as the name implies, describes the emergence of discontinuities in an organism's preferred environment , causing population fragmentation...
, none of the present habitat falls under the designation of National Forests
United States National Forest
National Forest is a classification of federal lands in the United States.National Forests are largely forest and woodland areas owned by the federal government and managed by the United States Forest Service, part of the United States Department of Agriculture. Land management of these areas...
but comes under the administration of the states' Department of Natural Resources
Department of Natural Resources
Many sub-national governments have a Department of Natural Resources or similarly named organization:Australia*Queensland Department of Natural Resources and MinesCanada*Natural Resources Canada*New Brunswick**New Brunswick Department of Natural Resources...
s or federal entities such as the Fish and Wildlife Service
United States Fish and Wildlife Service
The United States Fish and Wildlife Service is a federal government agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats...
. Remaining intact habitat areas include:
- Devil's Lake State Park, on the Baraboo RangeBaraboo RangeBaraboo Range is a monadnock located in Columbia and Sauk Counties, Wisconsin. It consists of highly eroded Precambrian metamorphic rock. It is about long and varies from 5 to in width. The Wisconsin River, previously traveling in a north to south direction, turns to the east just north of the...
in south-central Wisconsin - Savanna Army DepotSavanna Army DepotSavanna Army Depot was a installation, located on the eastern bank of the Mississippi River, in Carroll and Jo Daviess counties, around seven miles north of Savanna, Illinois. It was opened in 1917 as a proving and testing facility for weapons developed at Rock Island Arsenal. In 1921 it became a...
in extreme northwestern Illinois - Parts of the Upper Mississippi River National Wildlife and Fish RefugeUpper Mississippi River National Wildlife and Fish RefugeThe Upper Mississippi River National Wildlife and Fish Refuge is a . 261 river mile long National Wildlife Refuge located in and along the Upper Mississippi River. It runs from Wabasha, Minnesota in the north to Rock Island, Illinois in the south....
in eastern Minnesota and western Wisconsin - Richard J. Dorer Memorial Hardwood State ForestRichard J. Dorer Memorial Hardwood State ForestThe Richard J. Dorer Memorial Hardwood State Forest is a reserve of current and former forest in Minnesota's Driftless Area. Only of the land is state owned, with the remainder owned by private individuals and community groups, governed by easements...
in the Driftless Area of southeastern Minnesota - Whitewater State ParkWhitewater State ParkWhitewater State Park is a Minnesota state park in Winona County in the southeastern blufflands area of the state. The park features scenic overlooks and excellent trout fishing in the spring fed Whitewater River and Trout Run Creek. It has about 300,000 visitors annually, and is located 7 miles ...
, also in the Driftless Area - Necedah National Wildlife RefugeNecedah National Wildlife RefugeNecedah National Wildlife Refuge is a National Wildlife Refuge located in northern Juneau County, Wisconsin near the village of Necedah. It was established in 1939 and is famous as the northern nesting site for reintroduction of an eastern United States population of the endangered Whooping Crane...
in central Wisconsin - Horicon MarshHoricon MarshHoricon Marsh is a marsh located in northern Dodge and southern Fond du Lac counties of Wisconsin. It is the site of both a national and state wildlife refuge. The extinct glacial lake is the largest freshwater cattail marsh in the United States....
in southeastern Wisconsin - Kettle Moraine State ForestKettle Moraine State ForestThe Kettle Moraine State Forest is a state forest in southeastern Wisconsin, USA. The chief feature of the reserve is the Kettle Moraine, a highly glaciated area. The area contains very hilly terrain and glacial landforms, such as kettles, kames and eskers...
in southeastern Wisconsin
See also
- List of ecoregions in the United States (WWF)
- Cedar Creek Ecosystem Science ReserveCedar Creek Ecosystem Science ReserveThe Cedar Creek Ecosystem Science Reserve is an ecological research site located primarily in East Bethel, Minnesota in the counties of Anoka and Isanti on the northern edge of the Minneapolis-Saint Paul metropolitan area...
– an ecological researchEcosystem ecologyEcosystem ecology is the integrated study of biotic and abiotic components of ecosystems and their interactions within an ecosystem framework. This science examines how ecosystems work and relates this to their components such as chemicals, bedrock, soil, plants, and animals.Ecosystem ecology...
station specializing in fire ecologyFire ecologyFire ecology is concerned with the processes linking the natural incidence of fire in an ecosystem and the ecological effects of this fire. Many ecosystems, such as the North American prairie and chaparral ecosystems, and the South African savanna, have evolved with fire as a natural and necessary...
and its effects on oak savannas run by the University of MinnesotaUniversity of MinnesotaThe University of Minnesota, Twin Cities is a public research university located in Minneapolis and St. Paul, Minnesota, United States. It is the oldest and largest part of the University of Minnesota system and has the fourth-largest main campus student body in the United States, with 52,557... - Big WoodsBig WoodsBig Woods refers to a type of temperate hardwood forest ecoregion found in south-central Minnesota. "Big Woods" is a direct translation of the name given to the region by French explorers: Grand Bois.-Trees:...
- Oak savannaOak savannaAn oak savanna is a type of savanna, or lightly forested grassland, where oaks are the dominant tree species. These savannas were maintained historically through wildfires set by lightning, grazing, low precipitation, poor soil, and/or fires set by Native Americans...