|
Upper Midwest Forest–savanna Transition
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 an ecotone (a transitional area) between the tallgrass prairies to the west and the temperate deciduous forests 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. Fire and disturbance Historically, wildfire 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 grasses, forbs, shrubs, and sedges, increase with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devil's Lake State Park (Wisconsin)
Devil's Lake State Park is a state park located in the Baraboo Range in eastern Sauk County, Wisconsin, United States. It is just south of the city of Baraboo, around northwest of Madison, and is on the western edge of the last ice-sheet deposited during the Wisconsin glaciation. The state park encompasses , making it the largest in Wisconsin. The state park is known for its quartzite bluffs along the Devil's Lake, which was created by a glacier depositing terminal moraines that plugged the north and south ends of the gap in the bluffs during the last ice age approximately 12,000 years ago. The sand at the bottom of Devil's Lake is thought to be deposited by glaciers. There are many quartzite rock formations, such as Balanced Rock and Devil's Doorway, throughout the park. Effigy mounds are also located throughout the park. The park contains approximately eleven miles of the Ice Age Trail. Its scenery, along with its proximity to the Wisconsin Dells, has made it one of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperate Broadleaf And Mixed Forest
Temperate broadleaf and mixed forest is a temperate climate terrestrial habitat type defined by the World Wide Fund for Nature, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions. These forests are richest and most distinctive in central China and eastern North America, with some other globally distinctive ecoregions in the Himalayas, Western and Central Europe, the southern coast of the Black Sea, Australasia, Southwestern South America and the Russian Far East. Ecology The typical structure of these forests includes four layers. * The uppermost layer is the canopy composed of tall mature trees ranging from high. Below the canopy is the three-layered, shade-tolerant understory that is roughly shorter than the canopy. * The top layer of the understory is the sub-canopy composed of smaller mature trees, saplings, and suppressed juvenile canopy layer trees awaiting an opening in the canopy. * Below the sub-canop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildfire
A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a bushfire (Bushfires in Australia, in Australia), desert fire, grass fire, hill fire, Peat#Peat fires, peat fire, prairie fire, vegetation fire, or veld fire. Some natural forest ecosystems Fire ecology, depend on wildfire. Modern forest management often engages in prescribed burns to mitigate fire risk and promote natural forest cycles. However, controlled burns can turn into wildfires by mistake. Wildfires can be classified by cause of ignition, physical properties, combustible material present, and the effect of weather on the fire. Wildfire severity results from a combination of factors such as available fuels, physical setting, and weather. Climatic cycles with wet periods that create substantial fuels, followed by drought and heat, of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agriculture
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in the cities. While humans started gathering grains at least 105,000 years ago, nascent farmers only began planting them around 11,500 years ago. Sheep, goats, pigs, and cattle were domesticated around 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. In the 20th century, industrial agriculture based on large-scale monocultures came to dominate agricultural output. , small farms produce about one-third of the world's food, but large farms are prevalent. The largest 1% of farms in the world are greater than and operate more than 70% of the world's farmland. Nearly 40% of agricultural land is found on farms larger than . However, five of every six farm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, game reserves, or nature reserves. It can also be caused by immobile, travel restricted populations of native or non-native wild animals. Overgrazing reduces the usefulness, productivity and biodiversity of the land and is one cause of desertification and erosion. Overgrazing is also seen as a cause of the spread of invasive species of non-native plants and of weeds. Degrading land, emissions from animal agriculture and reducing the biomass in a ecosystem contribute directly to climate change between grazing events. Successful planned grazing strategies have been in support of the American bison of the Great Plains, or migratory wildebeest of the African savannas, or by holistic planned grazing. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Mississippi River
The Upper Mississippi River is the portion of the Mississippi River upstream of St. Louis, Missouri, United States, a city at the confluence of its main tributary, the Missouri River. Historically, it may refer to the area above the Arkansas Post, above the confluence of Ohio River, or above Cape Girardeau. History In terms of geologic and hydrographic history, the Upper Mississippi east and south of Fort Snelling is a portion of the now-extinct Glacial River Warren which carved the valley of the Minnesota River, permitting the immense Glacial Lake Agassiz to join the world's oceans at the Gulf of Mexico. The collapse of ice dams holding back Glacial Lake Duluth and Glacial Lake Grantsburg carved out the Dalles of the St. Croix River at Interstate Park. The Upper Mississippi River valley likely originated as an ice-marginal stream during the Pre-Illinoian Stage. The Driftless Area is a portion of North America left unglaciated at that ice age's height, hence not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperate Deciduous Forest
Temperate deciduous or temperate broadleaf forests are a variety of temperate forest 'dominated' by deciduous trees that lose their leaves each winter. They represent one of Earth's major biomes, making up 9.69% of global land area. These forests are found in areas with distinct seasonal variation that cycle through warm, moist summers, cold winters, and moderate fall and spring seasons. They are most commonly found in the Northern Hemisphere, with particularly large regions in eastern North America, East Asia, and a large portion of Europe, though smaller regions of temperate deciduous forests are also located in South America. Examples of trees typically growing in the Northern Hemisphere's deciduous forests include oak, maple, basswood, beech and elm, while in the Southern Hemisphere, trees of the genus ''Nothofagus'' dominate this type of forest. Temperate deciduous forests provide several unique ecosystem services, including habitats for diverse wildlife, and they face a set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tallgrass Prairie
The tallgrass prairie is an ecosystem native to central North America. Historically, natural and Historical ecology#Anthropogenic fire, anthropogenic fire, as well as grazing by large mammals (primarily bison) provided periodic disturbances to these ecosystems, limiting the encroachment of trees, recycling soil nutrients, and facilitating seed dispersal and germination. Prior to widespread use of the steel plow, which enabled large scale conversion to agricultural land use, tallgrass prairies extended throughout the Midwestern United States, American Midwest and smaller portions of southern Aspen parkland, central Canada, from the transitional ecotones out of eastern North American forests, west to a climatic threshold based on precipitation and soils, to the southern reaches of the Flint Hills in Kansas, to a transition into forest in Manitoba. They were characteristically found in parts of the upper Mississippi River Valley, in the central forest-grasslands transition, the centr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecotone
An ecotone is a transitional area between two plant communities, where these meet and integrate. Examples include areas between grassland and forest, estuaries and lagoon, freshwater and sea water etc. An ecotone may be narrow or wide, and it may be local (the zone between a field and forest) or regional (the transition between forest and grassland ecosystems). An ecotone may appear on the ground as a gradual blending of the two communities across a broad area, or it may manifest itself as a sharp boundary line. Etymology The word ''ecotone'' was coined (and its etymology given) in 1904 in "The Development and Structure of Vegetation" (Lincoln, Nebraska: Botanical Seminar) by Frederic E. Clements. It is formed as a combination of ''ecology'' plus ''-tone'', from the Greek ''tonos'' or tension – in other words, a place where ecologies are in tension. Features There are several distinguishing features of an ecotone. First, an ecotone can have a sharp vegetation transition, wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Midwest
The Upper Midwest is a northern subregion of the U.S. Census Bureau's Midwestern United States. Although the exact boundaries are not uniformly agreed upon, the region is usually defined to include the states of Iowa, Michigan, Minnesota and Wisconsin; some definitions include North Dakota, South Dakota, and parts of Nebraska and Illinois. Definitions The National Centers for Environmental Information considers the Upper Midwest climate region to include Iowa, Michigan, Minnesota, and Wisconsin. The United States Geological Survey uses two different Upper Midwest regions: *The USGS Upper Midwest Environmental Sciences Center considers it to be the six states of Illinois, Indiana, Iowa, Michigan, Minnesota and Wisconsin, which comprise the watersheds of the Upper Mississippi River and upper Great Lakes. *The USGS Mineral Resources Program considers the area to contain Illinois, Indiana, Michigan, Minnesota and Wisconsin. The Association for Institutional Research in the Uppe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Community
A plant community is a collection or Association (ecology), association of plant species within a designated geographical unit, which forms a relatively uniform patch, distinguishable from neighboring patches of different vegetation types. The components of each plant community are influenced by soil type, topography, climate and human disturbance. In many cases there are several soil types present within a given plant community. This is because the soil type within an area is influenced by two factors, the rate at which water infiltrates or exits (via evapotranspiration) the soil, as well as the rate at which organic matter (any carbon-based compound within the environment, such as decaying plant matter) enters or decays from the soil. Plant communities are studied substantially by ecologists, due to providing information on the effects of dispersal, tolerance to environmental conditions, and response to disturbance of a variety of plant species, information valuable to the comprehe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oak Savanna
An oak savanna is a type of savanna (or lightly forested grassland), where oaks (''Quercus ''spp.) are the dominant trees. It is also generally characterized by an understory that is lush with grass and herb-related plants. The terms "oakery" or "woodlands" are also used commonly, though the former is more prevalent when referencing the Mediterranean area. Oak savannas typically exist in areas with low precipitation and feature poor soils. Predominant land uses include rangeland agriculture. Naturally, these savannas depend on natural wildfires (e.g. caused by lightning) to maintain their open vegetation. United States Although there are pockets of oak savanna almost anywhere in North America where oaks are present, there are three major oak savanna areas: 1) California, British Columbia, Washington and Oregon in the west; 2) Southwestern United States and northern Mexico; and 3) the prairie/forest border zone of the Midwestern United States. There are also small areas of oak s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
