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Aristida Blakei
''Aristida'' is a very nearly cosmopolitan genus of plants in the grass family. ''Aristida'' is distinguished by having three awns (bristles) on each lemma of each floret. The genus includes about 300 species found worldwide, often in arid warm regions. This genus is among those colloquially called three-awns wiregrasses, speargrasses and needlegrasses. The name ''Aristida'' is derived from the Latin " arista", meaning "awn". They are characteristic of semiarid grassland. The Wiregrass Region of North America is named for '' A. stricta''. Other locales where this genus is an important component of the ecosystem include the Carolina Bays, the sandhills of the Carolinas, and elsewhere, Mulga scrub in Australia, and the xeric grasslands around Lake Turkana in Africa. Local increases in the abundance of wiregrasses is a good indicator of overgrazing, as livestock avoid them. Description ''Aristida'' stems are ascending to erect, with both basal and cauline leaves. The leave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristida Purpurea
''Aristida purpurea'' is a species of grass native to North America which is known by the common name purple three-awn. Distribution This grass is fairly widespread and can be found across the western two thirds of the United States, much of southern Canada and parts of northern Mexico. It is most abundant on the plains. Description This is a perennial bunchgrass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perennia ..., growing erect to under a meter-3 feet in height, and the flower glumes often assumes a light brown to reddish-purple color. There are several varieties with overlapping geographical ranges. This is not considered to be a good graze for livestock because the awns are sharp and the protein content of the grass is low. References External links Calflora Database: ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grassland
A grassland is an area where the vegetation is dominance (ecology), 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 Herbaceous plant, 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 Assessm ... [...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] |
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surface area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With nearly billion people as of , it accounts for about of the world's human population. Demographics of Africa, Africa's population is the youngest among all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Based on 2024 projections, Africa's population will exceed 3.8 billion people by 2100. Africa is the least wealthy inhabited continent per capita and second-least wealthy by total wealth, ahead of Oceania. Scholars have attributed this to different factors including Geography of Africa, geography, Climate of Africa, climate, corruption, Scramble for Africa, colonialism, the Cold War, and neocolonialism. Despite this lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Turkana
Lake Turkana () is a saline lake in the Kenyan Rift Valley, in northern Kenya, with its far northern end crossing into Ethiopia. It is the world's largest permanent desert lake and the world's largest alkaline lake. By volume it is the world's fourth-largest salt lake after the Caspian Sea, Issyk-Kul, and Lake Van (passing the shrinking South Aral Sea), and among all lakes it ranks 24th. Lake Turkana is now threatened by the construction of the Gilgel Gibe III Dam in Ethiopia due to the damming of the Omo river which supplies most of the lake's water. Although the lake commonly has been—and to some degree still is—used for drinking water, its salinity (slightly brackish) and very high levels of fluoride (much higher than in fluoridated water) generally make it unsuitable for drinking directly, and it has also been a source of diseases spread by contaminated water. Increasingly, communities on the lake's shores rely on underground springs for drinking water. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xeric
Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (Ancient Greek 'dry') shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this habitat type vary greatly in the amount of annual rainfall they receive, usually less than annually except in the margins. Generally evaporation exceeds rainfall in these ecoregions. Temperature variability is also diverse in these lands. Many deserts, such as the Sahara, are hot year-round, but others, such as East Asia's Gobi Desert, become quite cold during the winter. Temperature extremes are a characteristic of most deserts. High daytime temperatures give way to cold nights because there is no insulation provided by humidity and cloud cover. The diversity of climatic conditions, though quite harsh, supports a rich array of habitats. Many of these habitats are ephemeral in nature, reflecting the paucity and seasonality of available water. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller islands. It has a total area of , making it the list of countries and dependencies by area, sixth-largest country in the world and the largest in Oceania. Australia is the world's flattest and driest inhabited continent. It is a megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and Climate of Australia, climates including deserts of Australia, deserts in the Outback, interior and forests of Australia, tropical rainforests along the Eastern states of Australia, coast. The ancestors of Aboriginal Australians began arriving from south-east Asia 50,000 to 65,000 years ago, during the Last Glacial Period, last glacial period. By the time of British settlement, Aboriginal Australians spoke 250 distinct l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acacia Aneura
''Acacia aneura'', commonly known as mulga, is a species of flowering plant in the family Fabaceae and is endemic to inland Australia. It is a variable shrub or small tree with flat, narrowly linear to elliptic phyllodes, cylindrical spikes of bright yellow flowers and more or less flat and straight, leathery Pod (fruit), pods. Description ''Acacia aneura'' is a variable shrub or small tree that typically grows to a height of , sometimes up to and is often multistemmed with a bushy Crown (botany), crown. Its phyllodes are flat, narrowly linear to narrowly elliptic, long and mostly wide, straight or slightly curved. The flowers are borne in a cylindrical head in the axils of phyllodes on a hairy Peduncle (botany), peduncle long. The heads are long and bright yellow. Flowering occurs from March to May or August and the pod is more or less straight and flat, long and wide with a winged edge. The pods are papery, brown to greyish-brown, containing elliptic to oblong or e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandhill
A sandhill is a type of ecological community or xeric wildfire-maintained ecosystem. It is not the same as a sand dune. It features very short fire return intervals, one to five years. Without fire, sandhills undergo ecological succession and become more oak dominated. Entisols are the typical sandhill soil, deep well-drained and nutrient poor. In Florida, sandhills receive of rainfall per year, just like the more hydric ecosystems surrounding them. Sandhills are xeric because they have poor water holding capacity. Dominant vegetation includes longleaf pine (''Pinus palustris''), American turkey oak ('' Quercus laevis''), and wiregrass ('' Aristida stricta''). A number of rare animals are typical of this habitat including the gopher tortoise ('' Gopherus polyphemus''), red-cockaded woodpecker (''Picoides borealis''), Sherman's fox squirrel ('' Sciurus niger shermani''), and striped newt ('' Notophthalmus perstriatus''). Invasive species that are a problem on sandhills includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Carolinas
The Carolinas, also known simply as Carolina, are the U.S. states of North Carolina and South Carolina considered collectively. They are bordered by Virginia to the north, Tennessee to the west, and Georgia to the southwest. The Atlantic Ocean is to the east. Combining North Carolina's population of 10,439,388 and South Carolina's of 5,118,425, the Carolinas have a collective population of 15,557,813 as of 2020. If the Carolinas were a single state of the United States, it would be the fifth-most populous state, behind California, Texas, Florida, and New York. The Carolinas were known as the Province of Carolina during America's early colonial period, from 1663 to 1712. Prior to that, the land was considered part of the Colony and Dominion of Virginia, from 1609 to 1663. The province was named ''Carolina'' to honor King Charles I of England. Carolina is taken from the Latin word for "Charles", ''Carolus''. History The region was claimed as part of the Spanish territory n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandhills (Carolina)
The Sandhills or Carolina Sandhills is a 10-35 mi wide physiographic region within the U.S. Atlantic Coastal Plain province, along the updip (inland) margin of this province in the states of North Carolina, South Carolina, and Georgia. The extent of the Carolina Sandhills is shown in maps of the ecoregions of North Carolina, South Carolina, and Georgia. Geology The unconsolidated sand of the Carolina Sandhills is mapped as the Quaternary Pinehurst Formation, and is interpreted as eolian (wind-blown) sand sheets and dunes that were mobilized episodically from approximately 75,000 to 6,000 years ago. Most of the published luminescence ages from the sand are coincident with the last glaciation, a time when the southeastern United States was characterized by colder air temperatures, stronger winds, and less vegetation. The Carolina Sandhills region also contains outcrops of Cretaceous-age (~100 million years old) strata of sand, sandstone, and clay that are interpreted as fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carolina Bay
Carolina bays are elliptical to circular depressions concentrated along the East Coast of the United States within coastal New York, New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, and north Florida.Kaczorowski, R. T. (1977) ''The Carolina Bays: a Comparison with Modern Oriented Lakes'' Technical Report no. 13-CRD, Coastal research Division, Department of Geology, University of South Carolina, Columbia. In Maryland, they are called Maryland basins. Within the Delmarva Peninsula, they and other coastal ponds are also called Delmarva bays.Coleman, D. (2001''Delmarva Bays: Natural Enigmas.'' , Annapolis. Maryland. Origin of name The name "Carolina bay" is sometimes attributed to the writings of the English explorer[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
