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Pre-Columbian Savannas Of North America
Pre-Columbian woodlands of North America, consisting of a mixed woodland-grassland ecosystem, were maintained by both natural lightning fires and by Native Americans before the significant arrival of Europeans. Although decimated by widespread epidemic disease, Native Americans in the 16th century continued using fire to clear woodlands until European colonists began colonizing the eastern seaboard. Many colonists continued the practice of burning to clear underbrush, reinforced by their similar experience in Europe, but some land reverted to forest. Postglacial events During the Last Glacial Maximum about 18,000 years ago, the glacial front in the eastern United States extended south to the approximate location of the Missouri and Ohio River. These glaciers destroyed any vegetation in their path, and cooled the climate near their front. Pre-existing natural communities remained largely intact south of the glaciers, but saw an increase in dominance of pine and a now-extinct s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildland Fire In Ecosystems 15-1-2
Wilderness or wildlands (usually in the plural), are natural environments on Earth that have not been significantly modified by human activity or any nonurbanized land not under extensive agricultural cultivation. The term has traditionally referred to terrestrial environments, though growing attention is being placed on marine wilderness. Recent maps of wilderness suggest it covers roughly one quarter of Earth's terrestrial surface, but is being rapidly degraded by human activity. Even less wilderness remains in the ocean, with only 13.2% free from intense human activity. Some governments establish protection for wilderness areas by law to not only preserve what already exists, but also to promote and advance a natural expression and development. These can be set up in preserves, conservation preserves, national forests, national parks and even in urban areas along rivers, gulches or otherwise undeveloped areas. Often these areas are considered important for the survival of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Ecology
Fire ecology is a scientific discipline concerned with natural processes involving fire in an ecosystem and the ecological effects, the interactions between fire and the abiotic and biotic components of an ecosystem, and the role as an ecosystem process. Many ecosystems, particularly prairie, savanna, chaparral and coniferous forests, have evolved with fire as an essential contributor to habitat vitality and renewal. Many plant species in fire-affected environments require fire to germinate, establish, or to reproduce. Wildfire suppression not only eliminates these species, but also the animals that depend upon them. Campaigns in the United States have historically molded public opinion to believe that wildfires are always harmful to nature. This view is based on the outdated beliefs that ecosystems progress toward an equilibrium and that any disturbance, such as fire, disrupts the harmony of nature. More recent ecological research has shown, however, that fire is an integral com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pre-Columbian Era
In the history of the Americas, the pre-Columbian era spans from the Migration to the New World, original settlement of North and South America in the Upper Paleolithic period through European colonization of the Americas, European colonization, which began with Christopher Columbus's voyage of 1492. Usually, the era covers the history of Indigenous peoples of the Americas, Indigenous cultures until significant influence by Europeans. This may have occurred decades or even centuries after Columbus for certain cultures. Many pre-Columbian civilizations were marked by permanent settlements, cities, agriculture, civic and monumental architecture, major earthworks (archaeology), earthworks, and Complex society, complex societal hierarchies. Some of these civilizations had long faded by the time of the first permanent European colonies (c. late 16th–early 17th centuries), and are known only through archaeology of the Americas, archaeological investigations and oral history. Other civi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Native American History
The Indigenous peoples of the Americas are the inhabitants of the Americas before the arrival of the European settlers in the 15th century, and the ethnic groups who now identify themselves with those peoples. Many Indigenous peoples of the Americas were traditionally hunter-gatherers and many, especially in the Amazon basin, still are, but many groups practiced aquaculture and agriculture. While some societies depended heavily on agriculture, others practiced a mix of farming, hunting, and gathering. In some regions, the Indigenous peoples created monumental architecture, large-scale organized cities, city-states, chiefdoms, states, kingdoms, republics, confederacies, and empires. Some had varying degrees of knowledge of engineering, architecture, mathematics, astronomy, writing, physics, medicine, planting and irrigation, geology, mining, metallurgy, sculpture, and gold smithing. Many parts of the Americas are still populated by Indigenous peoples; some countries have size ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Plains
The Great Plains (french: Grandes Plaines), sometimes simply "the Plains", is a broad expanse of flatland in North America. It is located west of the Mississippi River and east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. It is the southern and main part of the Interior Plains, which also include the tallgrass prairie between the Great Lakes and Appalachian Plateau, and the Taiga Plains and Boreal Plains ecozones in Northern Canada. The term Western Plains is used to describe the ecoregion of the Great Plains, or alternatively the western portion of the Great Plains. The Great Plains lies across both Central United States and Western Canada, encompassing: * The entirety of the U.S. states of Kansas, Nebraska, North Dakota and South Dakota; * Parts of the U.S. states of Colorado, Iowa, Minnesota, Missouri, Montana, New Mexico, Oklahoma, Texas and Wyoming; * The southern portions of the Canadian provinces of Alberta, Saskatchewan and Manitoba. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grasslands Of The United States
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area. Definitions Included among the variety of definitions for grasslands are: * "...any plant community, including harvested forages, in which grasses and/or legumes make up the dominant vegetation." * "...terrestrial ecosystems dominated by herbaceous and shrub vegetation, and maintained by fire, grazing, drought and/or freezing temperatures." (Pilot Assessment of Global Ecosystems, 2000) * "A r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prairie Remnant
A prairie remnant commonly refers to grassland areas in the Western and Midwestern United States and Canada that remain to some extent undisturbed by European settlement. Prairie remnants range in levels of degradation but nearly all contain at least some semblance of the pre-Columbian local plant assemblage of a particular region. Prairie remnants have become increasingly threatened due to the threats of agricultural, urban and suburban development, pollution, fire suppression, and the incursion of invasive species. Prairie remnants in restoration ecology Prairie remnants offer valuable varieties of rare species thus providing excellent opportunities for restoration ecology projects. Many restoration projects are simply recreations of prairie habitats, but restoring prairie remnants provides the preservation of more complete ecological structures that were naturally created after the end of the last ice age. Remnants can also serve as platforms for additional surrounding ecolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terra Preta
''Terra preta'' (, locally , literally "black soil" in Portuguese) is a type of very dark, fertile anthropogenic soil ( anthrosol) found in the Amazon Basin. It is also known as "Amazonian dark earth" or "Indian black earth". In Portuguese its full name is or ("black soil of the Indian", "Indians' black earth"). ''Terra mulata'' ("mulatto earth") is lighter or brownish in color. ''Terra preta'' owes its characteristic black color to its weathered charcoal content, and was made by adding a mixture of charcoal, bones, broken pottery, compost and manure to the low fertility Amazonian soil. A product of indigenous soil management and slash-and-char agriculture, the charcoal is stable and remains in the soil for thousands of years, binding and retaining minerals and nutrients. ''Terra preta'' is characterized by the presence of low-temperature charcoal residues in high concentrations; of high quantities of tiny pottery shards; of organic matter such as plant residues, animal feces, ... [...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. The terms "oakery" or "woodlands" are also used commonly, though the former is more prevalent when referencing the Mediterranean area. These savannas were maintained historically through wildfires set by lightning, humans, grazing, low precipitation, and/or poor soil. 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 of the Midwestern United States. There are also small areas of oak savannas in other parts of the world. (See also Eastern savannas of the United States for information on pine savannas of the U.S. South.) Midwestern oak savannas The oak savannas of the Midwestern United States form a transition zone betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Savanna Oregon Oak Buttercup BLM
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the Canopy (forest), canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. According to ''Britannica'', there exists four savanna forms; ''savanna woodland'' where trees and shrubs form a light canopy, ''tree savanna'' with scattered trees and shrubs, ''shrub savanna'' with distributed shrubs, and ''grass savanna'' where trees and shrubs are mostly nonexistent.Smith, Jeremy M.B.. "savanna". Encyclopedia Britannica, 5 Sep. 2016, https://www.britannica.com/science/savanna/Environment. Accessed 17 September 2022. Savannas maintain an open canopy despite a high tree density. It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds ''in situ''. It does not include land that is predominantly under agricultural or urban use." Using this definition, '' Global Forest Resources Assessment 2020'' (FRA 2020) found that forests covered , or approximately 31 percent of the world's land area in 2020. Forests are the predominant terrestrial ecosystem of Earth, and are found around the globe. More than half of the world's forests are found in only five countries (Brazil, Canada, China, Russia, and the United States). The largest share of forests (45 percent) are in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Suppression
Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts in wild land areas require different techniques, equipment, and training from the more familiar structure fire fighting found in populated areas. Working in conjunction with specially designed aerial firefighting aircraft, these wildfire-trained crews suppress flames, construct fire break, fire lines, and extinguish flames and areas of heat to protect resources and natural wilderness. Wildfire suppression also addresses the issues of the wildland–urban interface, where populated areas border with wild land areas. In the United States and other countries, aggressive wildfire suppression aimed at minimizing fire has contributed to accumulation of fuel loads, increasing the risk of large, catastrophic fires. History Australia Wildland fire, known in Australia as bush fire, has played a major role in Australia due to arid conditions. Notable fire services tasked with wildfire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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