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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 Earth's natural environments 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 surviva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Ecology
Fire ecology is a scientific discipline concerned with the effects of fire on natural ecosystems. 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 use fire to germinate, establish, or to reproduce. Wildfire suppression not only endangers these species, but also the animals that depend upon them. History of wildfire suppression in the United States, Wildfire suppression campaigns in the United States have historically molded public opinion to believe that wildfires are harmful to nature. Ecological research has shown, however, that fire is an integral component in the function and biodiversity of many natural habitats, and that the organisms within these communities have adapted to withstand, and even to exploit, natural wildfire. More generally, fire is now regarded as a 'natural disturbance', similar to flooding, S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric North America
Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared years ago. It took thousands of years for writing systems to be widely adopted, with writing having spread to almost all cultures by the 19th century. The end of prehistory therefore came at different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. It is based on an old conception of history that without written records there could be no history. The most common conception today is that history is based on evidence, however the concept of prehistory hasn't been completely discarded. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Plains
The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include the mixed grass prairie, the tallgrass prairie between the Great Lakes and Appalachian Plateau, and the Taiga Plains Ecozone, Taiga Plains and Boreal Plains Ecozone, Boreal Plains ecozones in Northern Canada. "Great Plains", or Western Plains, is also the ecoregion of the Great Plains or the western portion of the Great Plains, some of which in the farthest west is known as the High Plains. The Great Plains lie across both the Central United States and Western Canada, encompassing: *Most or all of the U.S. states of Kansas, Nebraska, and North Dakota, North and South Dakota; *Eastern parts of the U.S. states of Colorado, Montana, and Wyoming; *Parts of the U.S. states of New Mexico, Oklahoma, Texas; *Sometimes western parts of Iowa, Minnesot ... [...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 such as 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 preserves more complete ecological structures that were naturally created after the end of the last ice age. Remnants can also be platforms for additional surrounding ecological restoration activi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terra Preta
''Terra preta'' (, literally "black soil" in Portuguese language, Portuguese), also known as Amazonian dark earth or Indian black earth, is a type of very dark, fertile human impact on the environment, anthropogenic soil (anthrosol) found in the Amazon Basin. In Portuguese its full name is or ' ("black soil of the Indigenous peoples of the Americas, 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 Indigenous peoples of the Amazon, Amazonian 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 ... [...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] |
Savanna Oregon Oak Buttercup BLM
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. Four savanna forms exist; ''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 spaced than in forests.Manoel Cláudio da Sil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest
A forest is an ecosystem characterized by a dense ecological community, community of 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 (biology), 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 (FRA), Global Forest Resources Assessment 2020'' found that forests covered , or approximately 31 percent of the world's land area in 2020. Forests are the largest Terrestrial ecosystem, terrestrial ecosystems of Earth by area, and are found around the globe. 45 percent of forest land is in the Tropical forest, trop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildfire Suppression
Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts depend on many factors such as the available fuel, the local atmospheric conditions, the features of the terrain, and the size of the wildfire. Because of this wildfire suppression in wild land areas usually requires 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, fire engines, tools, firefighting foams, fire retardants, and using various firefighting techniques, wildfire-trained crews work to suppress flames, construct fire lines, and extinguish flames and areas of heat in order 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
