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Salix Richardsonii
''Salix richardsonii'' is a species of flowering plant in the Salicaceae, or willow family. It is known by the common names Richardson's willow and woolly willow. It is native to Russia''Salix richardsonii''. Flora of North America. and northern North America, where it occurs in and northern Canada.Esser, Lora L. 1992 ''Salix richardsonii''. In: Fire Effects Information System, nline U.S. Department of Agriculture, Forest Service, Rocky Mountain Resear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Jackson Hooker
Sir William Jackson Hooker (6 July 178512 August 1865) was an English botany, botanist and botanical illustrator, who became the first director of Kew Gardens, Kew when in 1841 it was recommended to be placed under state ownership as a botanic garden. At Kew he founded the Kew Herbarium, Herbarium and enlarged the gardens and arboretum. Hooker was born and educated in Norwich. An inheritance gave him the means to travel and to devote himself to the study of natural history, particularly botany. He published his account of an expedition to Iceland in 1809, even though his notes and specimens were destroyed during his voyage home. He married Maria, the eldest daughter of the Norfolk banker Dawson Turner, in 1815, afterwards living in Halesworth for 11 years, where he established a herbarium that became renowned by botanists at the time. He held the post of Regius Professor of Botany at Glasgow University, where he worked with the botanist and lithographer Thomas Hopkirk and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Line
The tree line is the edge of a habitat at which trees are capable of growing and beyond which they are not. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually low temperatures, extreme snowpack, or associated lack of available moisture). The tree line is sometimes distinguished from a lower timberline, which is the line below which trees form a forest with a closed Canopy (biology), canopy. At the tree line, tree growth is often sparse, stunted, and deformed by wind and cold. This is sometimes known as (German for "crooked wood"). The tree line often appears well-defined, but it can be a more gradual transition. Trees grow shorter and often at lower densities as they approach the tree line, above which they are unable to grow at all. Given a certain latitude, the tree line is approximately 300 to 1000 meters below the permanent snow line and roughly parallel to it. Causes Due to their vertical s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salicylic Acid
Salicylic acid is an organic compound with the formula HOC6H4COOH. A colorless (or white), bitter-tasting solid, it is a precursor to and a active metabolite, metabolite of acetylsalicylic acid (aspirin). It is a plant hormone, and has been listed by the EPA Toxic Substances Control Act (TSCA) Chemical Substance Inventory as an experimental teratogen. The name is from Latin for willow tree, from which it was initially identified and derived. It is an ingredient in some anti-acne products. Salts and esters of salicylic acid are known as salicylates. Uses Medicine Salicylic acid as a medication is commonly used to remove the outermost layer of the skin. As such, it is used to treat warts, psoriasis, acne vulgaris, ringworm, dandruff, and ichthyosis. Similar to other hydroxy acids, salicylic acid is an ingredient in many skincare products for the treatment of seborrhoeic dermatitis, acne, psoriasis, calluses, Corn (medicine), corns, keratosis pilaris, acanthosis nigricans, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basket Weaving
Basket weaving (also basketry or basket making) is the process of weaving or sewing pliable materials into three-dimensional artifacts, such as baskets, mats, mesh bags or even furniture. Craftspeople and artists specialized in making baskets may be known as basket makers and basket weavers. Basket weaving is also a rural craft. Basketry is made from a variety of fibrous or pliable materials—anything that will bend and form a shape. Examples include pine, straw, willow (esp. osier), oak, wisteria, forsythia, vines, stems, fur, hide, grasses, thread, and fine wooden splints. There are many applications for basketry, from simple mats to hot air balloon gondolas. Many Indigenous peoples are renowned for their basket-weaving techniques. History While basket weaving is one of the widest spread crafts in the history of any human civilization, it is hard to say just how old the craft is, because natural materials like wood, grass, and animal remains decay naturally and con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Native Americans In The United States
Native Americans (also called American Indians, First Americans, or Indigenous Americans) are the Indigenous peoples of the Americas, Indigenous peoples of the United States, particularly of the Contiguous United States, lower 48 states and Alaska. They may also include any Americans whose origins lie in any of the indigenous peoples of North or South America. The United States Census Bureau publishes data about "American Indians and Alaska Natives", whom it defines as anyone "having origins in any of the original peoples of North and South America ... and who maintains tribal affiliation or community attachment". The census does not, however, enumerate "Native Americans" as such, noting that the latter term can encompass a broader set of groups, e.g. Native Hawaiians, which it tabulates separately. The European colonization of the Americas from 1492 resulted in a Population history of Indigenous peoples of the Americas, precipitous decline in the size of the Native American ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beaver Dam
A beaver dam or beaver impoundment is a dam built by beavers; it creates a pond which protects against predators such as coyotes, alligators, cougars, foxes, eagles, wolves and bears, and holds their food during winter. These structures modify the natural environment in such a way that the overall ecosystem builds upon the change, making beavers a keystone species and ecosystem engineers. They build prolifically at night, carrying mud with their forepaws and timber between their teeth. Construction A minimum water level of is required to keep the underwater entrance to beaver lodges from being blocked by ice during the winter. In lakes, rivers and large streams with deep enough water, beavers may not build dams, and live in bank burrows and lodges. Beavers start construction by diverting the stream to lessen the water's flow pressure. Branches and logs are then driven into the mud of the stream bed to form a base. Then sticks, bark (from deciduous trees), rocks, mud, grass, leav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beaver
Beavers (genus ''Castor'') are large, semiaquatic rodents of the Northern Hemisphere. There are two existing species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers are the second-largest living rodents, after capybaras, weighing up to . They have stout bodies with large heads, long chisel-like incisors, brown or gray fur, hand-like front feet, webbed back feet, and tails that are flat and scaly. The two species differ in skull and tail shape and fur color. Beavers can be found in a number of freshwater habitats, such as rivers, streams, lakes and ponds. They are herbivorous, consuming tree bark, aquatic plants, grasses and sedges. Beavers build dams and lodges using tree branches, vegetation, rocks and mud; they chew down trees for building material. Dams restrict water flow, forming ponds, and lodges (usually built in ponds) serve as shelters. Their infrastructure creates wetlands used by many other species, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caribou
The reindeer or caribou (''Rangifer tarandus'') is a species of deer with circumpolar distribution, native to Arctic, subarctic, tundra, boreal, and mountainous regions of Northern Europe, Siberia, and North America. It is the only representative of the genus ''Rangifer''. More recent studies suggest the splitting of reindeer and caribou into six distinct species over their range. Reindeer occur in both migratory and sedentary populations, and their herd sizes vary greatly in different regions. The tundra subspecies are adapted for extreme cold, and some are adapted for long-distance migration. Reindeer vary greatly in size and color from the smallest, the Svalbard reindeer (''R.'' (''t.'') ''platyrhynchus''), to the largest, Osborn's caribou (''R. t. osborni''). Although reindeer are quite numerous, some species and subspecies are in decline and considered vulnerable. They are unique among deer (Cervidae) in that females may have antlers, although the prevalence of an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moose
The moose (: 'moose'; used in North America) or elk (: 'elk' or 'elks'; used in Eurasia) (''Alces alces'') is the world's tallest, largest and heaviest extant species of deer and the only species in the genus ''Alces''. It is also the tallest, and the second-largest, land animal in North America, falling short only to the American bison in body mass. Most adult male moose have broad, palmate ("open-hand shaped") antlers; other members of the deer family have pointed antlers with a dendritic ("twig-like") configuration. Moose inhabit the circumpolar boreal forests or temperate broadleaf and mixed forests of the Northern Hemisphere, thriving in cooler, temperate areas as well as subarctic climates. Hunting shaped the relationship between moose and humans, both in Eurasia and North America. Prior to the colonial era (around 1600–1700 CE), moose were one of many valuable sources of sustenance for certain tribal groups and First Nations. Hunting and habitat loss hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tundra
In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic, Antarctic. Tundra vegetation is composed of dwarf shrubs, Cyperaceae, sedges, Poaceae, grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus. The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in the permafrost, making the tundra soil a carbon sink. As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained greenhouse gases into the atmosphere, creating Climate change feedback, a feedback cycle t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pingo
Pingos are intrapermafrost ice-cored hills, high and in diameter. They are typically conical in shape and grow and persist only in permafrost environments, such as the Arctic and subarctic. A pingo is a Periglaciation, periglacial landform, which is defined as a non-glacial landform or process linked to colder climates. It is estimated that there are more than 11,000 pingos on Earth, with the Tuktoyaktuk peninsula area having the greatest concentration at a total of 1,350. History In 1825, John Franklin made the earliest description of a pingo when he climbed a small pingo on Ellice Island in the Mackenzie River, Mackenzie Delta. However, it was in 1938 that the term ''pingo'' was first borrowed from the Inuvialuit by the Arctic botanist Erling Porsild, Alf Erling Porsild in his paper on Earth mounds of the western Arctic coast of Canada and Alaska. Porsild Pingo in Tuktoyaktuk is named in his honour. The term pingo, which in Inuvialuktun means conical hill, has now been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floodplain
A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrology), discharge.Goudie, A. S., 2004, ''Encyclopedia of Geomorphology'', vol. 1. Routledge, New York. The soils usually consist of clays, silts, sands, and gravels deposited during floods. Because of regular flooding, floodplains frequently have high soil fertility since nutrients are deposited with the flood waters. This can encourage farming; some important agricultural regions, such as the Nile and Mississippi Basin, Mississippi Drainage basin, river basins, heavily exploit floodplains. Agricultural and urban regions have developed near or on floodplains to take advantage of the rich soil and freshwater. However, the Flood risk, risk of inundation has led to increasing efforts to Flood control, control flooding. Formation Most floodplai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
