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Tundra
In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mountain tract". There are three regions and associated types of tundra: Arctic tundra, alpine tundra, and Antarctic tundra. Tundra vegetation is composed of dwarf shrubs, sedges, 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-containe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tundra In Siberia
In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mountain tract". There are three regions and associated types of tundra: Arctic tundra, alpine tundra, and Antarctic tundra. Tundra vegetation is composed of dwarf shrubs, sedges, 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-conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reindeer
Reindeer (in North American English, known as caribou if wild and ''reindeer'' if domesticated) are deer in the genus ''Rangifer''. For the last few decades, reindeer were assigned to one species, ''Rangifer tarandus'', with about 10 subspecies. A 2022 revision of the genus elevated five of the subspecies to species (see Taxonomy below). They have a circumpolar distribution and are native to the Arctic, sub-Arctic, tundra, boreal forest, and mountainous regions of northern Europe, Siberia, and North America. 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 species, the Svalbard reindeer (''R. t. platyrhynchus''), to the largest subspecies, Osborn's caribou (''R. t. osborni''). Although reindeer are quite numerous, some species and subspecies are i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpine Tundra
Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets lower until it reaches sea level, and alpine tundra merges with polar tundra. The high elevation causes an adverse climate, which is too cold and windy to support tree growth. Alpine tundra transitions to sub-alpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as '' Krummholz''. With increasing elevation it ends at the snow line where snow and ice persist through summer. Alpine tundra occurs in mountains worldwide. The flora of the alpine tundra is characterized by dwarf shrubs close to the ground. The cold climate of the alpine tundra is caused by adiabatic cooling of air, and is similar to polar climate. Geography Alpine tundra occurs at high enough altitude at any latitude. Por ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taiga
Taiga (; rus, тайга́, p=tɐjˈɡa; relates to Mongolic and Turkic languages), generally referred to in North America as a boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, and larches. The taiga or boreal forest has been called the world's largest land biome. In North America, it covers most of inland Canada, Alaska, and parts of the northern contiguous United States. In Eurasia, it covers most of Sweden, Finland, much of Russia from Karelia in the west to the Pacific Ocean (including much of Siberia), much of Norway and Estonia, some of the Scottish Highlands, some lowland/coastal areas of Iceland, and areas of northern Kazakhstan, northern Mongolia, and northern Japan (on the island of Hokkaidō). The main tree species, depending on the length of the growing season and summer temperatures, vary across the world. The taiga of North America is mostly spruce, Scandinavian and Finnish taiga consists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Line
The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold 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. At the tree line, tree growth is often sparse, stunted, and deformed by wind and cold. This is sometimes known as '' krummholz'' (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 structure, trees are more sus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Climate
The polar climate regions are characterized by a lack of warm summers but with varying winters. Every month in a polar climate has an average temperature of less than . Regions with polar climate cover more than 20% of the Earth's area. Most of these regions are far from the equator and near the poles, and in this case, winter days are extremely short and summer days are extremely long (could last for the entirety of each season or longer). A polar climate consists of cool summers and very cold winters, which results in treeless tundra, glaciers, or a permanent or semi-permanent layer of ice. It is identified with the letter E in the Köppen climate classification. Subtypes There are two types of polar climate: ET, or tundra climate; and EF, or ice cap climate. A tundra climate is characterized by having at least one month whose average temperature is above , while an ice cap climate has no months averaging above . In a tundra climate, even coniferous trees cannot grow, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nenet People
The Nenets ( yrk, ненэй ненэче, ''nenəj nenəče'', russian: ненцы, ''nentsy''), also known as Samoyed, are a Samoyedic ethnic group native to northern Arctic Russia, Russian Far North. According to the latest census in 2010, there were 44,857 Nenets in the Russian Federation, most of them living in the Yamalo-Nenets Autonomous Okrug, Nenets Autonomous Okrug and Taymyrsky Dolgano-Nenetsky District stretching along the coastline of the Arctic Ocean near the Arctic Circle between Kola and Taymyr peninsulas. The Nenets people speak either the Tundra or Forest Nenets languages, which are mutually unintelligible. In the Russian Federation they have a status of indigenous small-numbered peoples. Today, the Nenets people face numerous challenges from the state and oil and gas companies that threaten the environment and their way of life. As a result, many cite a rise in locally based activism. Name The literal morphs ''samo'' and ''yed'' in Russian convey the mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poaceae
Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns and pasture. The latter are commonly referred to collectively as grass. With around 780 genera and around 12,000 species, the Poaceae is the fifth-largest plant family, following the Asteraceae, Orchidaceae, Fabaceae and Rubiaceae. The Poaceae are the most economically important plant family, providing staple foods from domesticated cereal crops such as maize, wheat, rice, barley, and millet as well as feed for meat-producing animals. They provide, through direct human consumption, just over one-half (51%) of all dietary energy; rice provides 20%, wheat supplies 20%, maize (corn) 5.5%, and other grains 6%. Some members of the Poaceae are used as building materials (bamboo, thatch, and straw); others can provide a source of biofuel, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not s. They may have tiny, leafless branches (); flat leaf-like structures ( [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Vegetation
About 1,702 species of plants live on the Arctic tundra, including flowering plants, short shrubs, herbs, grasses, mosses. These plants are adapted to short, cold growing seasons. They have the ability to withstand extremely cold temperatures in the winter (winter hardiness), and grow and reproduce in summer conditions that are quite limiting. As of 2005, arctic vegetation covered approximately of land. The area of arctic vegetation decreased by approximately from 1980 to 2000, with a corresponding increase in the boreal forest. This decrease is linked to the warming of the Arctic due to climate change. Adaptations Arctic plants have a number of adaptations to the compressed growing season and low temperatures: * They initiate growth rapidly in the spring, and flower and set seed much sooner than plants that grow in warmer conditions. * Their peak metabolic rate occurs at a much lower temperature than plants from farther south, but only peaks for a short growing season. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permafrost Carbon Cycle
The permafrost carbon cycle or Arctic carbon cycle is a sub-cycle of the larger global carbon cycle. Permafrost is defined as subsurface material that remains below 0o C (32o F) for at least two consecutive years. Because permafrost soils remain frozen for long periods of time, they store large amounts of carbon and other nutrients within their frozen framework during that time. Permafrost represents a large carbon reservoir that is seldom considered when determining global terrestrial carbon reservoirs. Recent and ongoing scientific research however, is changing this view. The permafrost carbon cycle deals with the transfer of carbon from permafrost soils to terrestrial vegetation and microbes, to the atmosphere, back to vegetation, and finally back to permafrost soils through burial and sedimentation due to cryogenic processes. Some of this carbon is transferred to the ocean and other portions of the globe through the global carbon cycle. The cycle includes the exchange of carb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nganasan People
The Nganasans (; Nganasan: ''ŋənəhsa(nəh)'', ''ńæh'') are a Uralic people of the Samoyedic branch native to the Taymyr Peninsula in north Siberia. In the Russian Federation, they are recognized as one of the indigenous peoples of the Russian North. They reside primarily in the settlements of Ust-Avam, Volochanka, and Novaya in the Taymyrsky Dolgano-Nenetsky District of Krasnoyarsk Krai, with smaller populations residing in the towns of Dudinka and Norilsk as well. The Nganasans are thought to be the direct descendants of proto-Uralic peoples. However there is some evidence that they absorbed local Paleo-Siberian population. The Nganasans were traditionally a semi-nomadic people whose main form of subsistence was wild reindeer hunting, in contrast to the Nenets, who herded reindeer. Beginning in the early 17th century, the Nganasans were subjected to the yasak system of Czarist Russia. They lived relatively independently, until the 1970s, when they were settled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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