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Glacial Refugium
A glacial refugium (''plural refugia'') is a geographic region which made possible the survival of flora and fauna in times of ice ages and allowed for post-glacial re-colonization. Different types of glacial refugia can be distinguished, namely nunatak, peripheral and lowland refugia.Holderegger, R., Thiel-Egenter, C. (2009): A discussion of different types of glacial refugia used in mountain biogeography and phytogeography. Journal of Biogeography 36, 476-480. Glacial refugia have been suggested as a major cause of the patterns of distributions of flora and fauna in both temperate and tropical latitudes. With respect to disjunct populations of modern-day species distributions, especially in birds, doubt has been cast on the validity of such inferences, as much of the differentiation between populations observed today may have occurred before or after their restriction to refugia. In contrast, isolated geographic locales that host one or more critically endangered species (regarded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms ''gut flora'' or ''skin flora''. Etymology The word "flora" comes from the Latin name of Flora (mythology), Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic composition of a community) was first made by Jules Thurmann (1849). Prior to this, the two terms were used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peak Glacial Refuges Eastern North America
Peak or The Peak may refer to: Basic meanings Geology * Mountain peak ** Pyramidal peak, a mountaintop that has been sculpted by erosion to form a point Mathematics * Peak hour or rush hour, in traffic congestion * Peak (geometry), an (''n''-3)-dimensional element of a polytope * Peak electricity demand or peak usage * Peak-to-peak, the highest (or sometimes the highest and lowest) points on a varying waveform * Peak (pharmacology), the time at which a drug reaches its maximum plasma concentration * Peak experience, psychological term for a euphoric mental state Resource production In terms of resource production, the peak is the moment when the production of a resource reaches a maximum level, after which it declines; in particular see: * Peak oil * Peak car * Peak coal * Peak copper * Peak farmland * Peak gas * Peak gold * Peak minerals * Peak phosphorus * Peak uranium * Peak water * Peak wheat * Peak wood Other basic meanings * Visor, a part of a hat, known as a "peak" in B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Last Glacial Maximum Refugia
Last Glacial Maximum refugia were places ('' refugia'') in which humans and other species survived during the Last Glacial Period in the Northern Hemisphere, around 25,000 to 20,000 years ago. Sub-Saharan Africa and Australia were not affected by the glaciation, although vast areas of those continents were too dry for human habitation of any sort, even by the most specialised and well-adapted foragers. New Zealand had no humans at the time. Some recent archaeological evidence suggests the possibility that human arrival in the Americas may have occurred prior to the Last Glacial Maximum more than 20,000 years ago, including possibly areas adjacent to ice sheets, but research is still in an early stage. The best attested shelters are therefore mainly those in Eurasia. Several of them have been studied. Europe * Solutrean *Gravettian *Pavlovian culture *Franco-Cantabrian region * Würm glaciation North Africa *Ibero-Maurusian *Capsian culture Asia *Kebaran culture *Japan, Jōm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drought Refuge
A drought refuge is a site that provides permanent fresh water or moist conditions for plants and animals, acting as a refuge habitat when surrounding areas are affected by drought and allowing ecosystems and core species populations to survive until the drought breaks. Drought refuges are important for conserving ecosystems in places where the effects of climatic variability are exacerbated by human activities. Description Reliable drought refuges are characterised by the ability to retain sufficient water throughout the drought, having water quality good enough to maintain the life of the ecosystem that are not subject to physical disturbance and that have access to surrounding habitat, so that refugees can recolonise the main habitat when the drought ends. For fish and aquatic invertebrates a drought refuge may be an isolated permanent pool in a stream that ceases to flow and mostly dries up during a period of drought.Bond, N.R. (2007). ''Identifying, mapping and managing dr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chattahoochee River
The Chattahoochee River forms the southern half of the Alabama and Georgia border, as well as a portion of the Florida - Georgia border. It is a tributary of the Apalachicola River, a relatively short river formed by the confluence of the Chattahoochee and Flint rivers and emptying from Florida into Apalachicola Bay in the Gulf of Mexico. The Chattahoochee River is about long. The Chattahoochee, Flint, and Apalachicola rivers together make up the Apalachicola–Chattahoochee–Flint River Basin (ACF River Basin). The Chattahoochee makes up the largest part of the ACF's drainage basin. Course The source of the Chattahoochee River is located in Jacks Gap at the southeastern foot of Jacks Knob, in the very southeastern corner of Union County, in the southern Blue Ridge Mountains, a subrange of the Appalachian Mountains. The headwaters of the river flow south from ridges that form the Tennessee Valley Divide. The Appalachian Trail crosses the river's uppermost headwaters. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxus Floridana
''Taxus floridana'', the Florida yew, is a species of yew, endemic to a small area of under 10 km² on the eastern side of the Apalachicola River in mesophytic forests of northern Florida at altitudes of 15–40 m. It is listed as critically endangered.Flora of North America''Taxus floridana''/ref> It is protected in reserves at the Torreya State Park and at the Nature Conservancy's Apalachicola Bluffs and Ravines Preserve, and has legal protection under the United States and Florida Endangered Species laws. Description It is an evergreen coniferous shrub or small tree growing to 6 m (rarely 10 m) tall, with a trunk up to 38 cm diameter. The bark is thin, scaly purple-brown, and the branches are irregularly orientated. The shoots are green at first, becoming brown after three or four years. The leaves are thin, flat, slightly falcate (sickle-shaped), 1–2.9 cm long and 1–2 mm broad, with a bluntly acute apex; they are arranged spirally on the shoots but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torreya Taxifolia
''Torreya taxifolia'', commonly known as Florida torreya or stinking-cedar, but also sometimes as Florida nutmeg or gopher wood, is an endangered subcanopy tree of the yew family, Taxaceae. It is native to only a small glacial refugium in the southeastern United States, at the state border region of northern Florida and southwestern Georgia. Species discovery In 1821 colonial control of the Florida Territory shifted from Spain to the United States. Plantation owners and their slaves began to move into the territory, exacerbating conflicts with the native peoples and the existing population of runaway slaves. One such plantation owner was the patriarch of the Croom family, who in 1826 purchased land around the town of Tallahassee. When he died in 1829, his two sons inherited and invested further in the region, buying up or leasing other plantations. One of the two sons was Hardy Bryan Croom. Croom had studied law and became a state senator in North Carolina in his early thirti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altamaha River
The Altamaha River is a major river in the U.S. state of Georgia. It flows generally eastward for 137 miles (220 km) from its origin at the confluence of the Oconee River and Ocmulgee River towards the Atlantic Ocean, where it empties into the ocean near Brunswick, Georgia. No dams are directly on the Altamaha, though some are on the Oconee and the Ocmulgee. Including its tributaries, the Altamaha River's drainage basin is about in size, qualifying it among the larger river basins of the US Atlantic coast.The Altamaha River Course [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippi River
The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The main stem is entirely within the United States; the total drainage basin is , of which only about one percent is in Canada. The Mississippi ranks as the thirteenth-largest river by discharge in the world. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. Native Americans have lived along the Mississippi River and its tributaries for thousands of years. Most were hunter-gathere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picea Critchfieldii
''Picea critchfieldii'' (common name: Critchfield's spruce) is an extinct species of spruce tree formerly present on the landscape of North America, where it was once widely distributed throughout the southeastern United States. Plant macrofossil evidence reveals that this tree became extinct during the Late Quaternary period of Earth's history. At present, this is the only documented plant extinction from this geologic era. Hypotheses as to what specifically drove the extinction remain unresolved, but rapid and widespread climatic changes coincided with ''Picea critchfieldii'''s decline and ultimate extinction. Description Species discovery Discoverers ''Picea critchfieldii'' was first described in 1999 by Stephen T. Jackson and Chengyu Weng in a paper titled, "Late Quaternary Extinction of a Tree Species in Eastern North America" published in the journal Proceedings of the National Academy of Sciences of the United States. Namesake ''Picea critchfieldii'', or Critch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleoendemic
Paleoendemism along with neoendemism is a possible subcategory of endemism. Paleoendemism refers to species that were formerly widespread but are now restricted to a smaller area. Neoendemism refers to species that have recently arisen, such as through divergence and reproductive isolation or through hybridization and polyploidy in plants. Etymology The first part of the word, paleo, comes from the Greek word ''palaiós, meaning "ancient".'' The second part of the word, ''endemism'' is from New Latin ''endēmicus'', from Greek ενδήμος, ''endēmos'', "native". ''Endēmos'' is formed of ''en'' meaning "in", and ''dēmos'' meaning "the people". Causes Changes in climate are thought to be the driving force in creating paleoendemic species, generally due to habitat loss. Regions where the climate has remained relatively stable form refugia which are more likely to be endemic hotspots today. This applies to both neoendemism and paleoendemism. However, paleoendemism differs as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appalachian Mountains
The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They once reached elevations similar to those of the Alps and the Rocky Mountains before experiencing natural erosion. The Appalachian chain is a barrier to east–west travel, as it forms a series of alternating ridgelines and valleys oriented in opposition to most highways and railroads running east–west. Definitions vary on the precise boundaries of the Appalachians. The United States Geological Survey (USGS) defines the ''Appalachian Highlands'' physiographic division as consisting of 13 provinces: the Atlantic Coast Uplands, Eastern Newfoundland Atlantic, Maritime Acadian Highlands, Maritime Plain, Notre Dame and Mégantic Mountains, Western Newfoundland Mountains, Piedmont, Blue Ridge, Valley and Ridge, St. Lawrence Valley, A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
