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Silene Stenophylla
''Silene stenophylla'' is a species of flowering plant in the family (biology), family Caryophyllaceae. Commonly called narrow-leafed campion, it is a species in the genus ''Silene''. It grows in the Arctic tundra of far eastern Siberia and the mountains of northern Japan. Frozen samples, estimated via radiocarbon dating to be around 32,000 years old, were discovered in the same area as current living specimens, and in 2012, a team of scientists successfully regenerated a plant from the samples. Habitat and description ''S. stenophylla'' grows in the Arctic tundra of far eastern Siberia and the mountains of northern Japan. It is typically tall, has narrow leaves, and a large calyx (flower), calyx. It blooms during the summer and has incised petals that are lilac, light pink, or white in color. It is a perennial that grows on stony cliffs and sandy shores. ''S. stenophylla'' is one of a few Beringian plant species that did not establish itself in North America. Etymology The bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Friedrich Von Ledebour
Carl Friedrich von Ledebour (8 July 1786, Stralsund – 4 July 1851, Munich;NDB/ADB Deutsche Biographie also Karl Friedrich von Ledebour) was a -n . Between 1811 and 1836, he was professor of science in the , Estonia. His most important works were ''Flora Altaica'', the first |
Radiocarbon
Carbon-14, C-14, or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples. Carbon-14 was discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, California. Its existence had been suggested by Franz Kurie in 1934. There are three naturally occurring isotopes of carbon on Earth: carbon-12 (), which makes up 99% of all carbon on Earth; carbon-13 (), which makes up 1%; and carbon-14 (), which occurs in trace amounts, making up about 1 or 1.5 atoms per 1012 atoms of carbon in the atmosphere. Carbon-12 and carbon-13 are both stable, while carbon-14 is unstable and has a half-life of 5,730 ± 40 years. Carbon-14 decays into nitrogen-14 () through beta decay. A gram of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Tissue Culture
Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition. It is widely used to produce clones of a plant in a method known as micropropagation. Different techniques in plant tissue culture may offer certain advantages over traditional methods of propagation, including: * The production of exact copies of plants that produce particularly good flowers, fruits, or have other desirable traits. * To quickly produce mature plants. * The production of multiples of plants in the absence of seeds or necessary pollinators to produce seeds. * The regeneration of whole plants from plant cells that have been genetically modified. * The production of plants in sterile containers that allows them to be moved with greatly reduced chances of transmitting diseases, pests, and pathogens. * The production of plants from seeds that otherwise have very low chances of germinating an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russian Academy Of Sciences
The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across the Russian Federation; and additional scientific and social units such as libraries, publishing units, and hospitals. Peter the Great established the Academy (then the St. Petersburg Academy of Sciences) in 1724 with guidance from Gottfried Leibniz. From its establishment, the Academy benefitted from a slate of foreign scholars as professors; the Academy then gained its first clear set of goals from the 1747 Charter. The Academy functioned as a university and research center throughout the mid-18th century until the university was dissolved, leaving research as the main pillar of the institution. The rest of the 18th century continuing on through the 19th century consisted of many published academic works from Academy scholars and a few Ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecosystem
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the system through photosynthesis and is incorporated into plant tissue. By feeding on plants and on one another, animals play an important role in the movement of matter and energy through the system. They also influence the quantity of plant and microbial biomass present. By breaking down dead organic matter, decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to a form that can be readily used by plants and microbes. Ecosystems are controlled by external and internal factors. External factors such as climate, parent material which forms the soil and topography, control the overall structure of an ecosystem but are not themselves influenced by the ecosystem. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steppe
In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslands, savannas and shrublands biome A steppe may be semi-arid or covered with grass or with shrubs or with both, depending on the season and latitude. The term " steppe climate" denotes the climate encountered in regions too dry to support a forest but not dry enough to be a desert. Steppe soils are typically of the chernozem type. Steppes are usually characterized by a semi-arid or continental climate. Extremes can be recorded in the summer of up to and in winter, . Besides this major seasonal difference, fluctuations between day and night are also very great. In both the highlands of Mongolia and northern Nevada, can be reached during the day with sub-freezing readings at night. Mid-latitude steppes feature hot summers and cold wint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chersky (urban-type Settlement)
Chersky (also anglicized Cherskiy) (russian: Че́рский; sah, Черскэй) is an urban locality (an urban-type settlement) and the administrative center of Nizhnekolymsky District of the Sakha Republic, Russia, located on the Kolyma River, east from Yakutsk, the capital of the republic. As of the 2010 Census, its population was 2,857. It was previously known as ''Nizhniye Kresty'' (until 1963). In 1989 the population of Chersky peaked on 11,176 inhabitants; however, like the most Soviet settlements in the Arctic, it has been largely abandoned after the dissolution of the Soviet Union as most of its residents left. A similar depopulation happened in Magadan Oblast and Chukotka, and in lighter scale in the Russian Far East. History It was founded as Nizhniye Kresty () in 1931. In 1963, it was granted urban-type settlement status''Registry of the Administrative-Territorial Divisions of the Sakha Republic'' and renamed Chersky, after Jan Czerski, a Polish geog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene Park
Pleistocene Park (russian: Плейстоценовый парк, Pleystotsenovyy park) is a nature reserve on the Kolyma River south of Chersky in the Sakha Republic, Russia, in northeastern Siberia, where an attempt is being made to re-create the northern subarctic steppe grassland ecosystem that flourished in the area during the last glacial period. The project is being led by Russian scientists Sergey Zimov and Nikita Zimov, testing the hypothesis that repopulating with large herbivores (and predators) can restore rich grasslands ecosystems, as expected if overhunting, and not climate change, was primarily responsible for the extinction of wildlife and the disappearance of the grasslands at the end of the Pleistocene epoch. The aim of the project is to research the climatic effects of the expected changes in the ecosystem. Here the hypothesis is that the change from tundra to grassland will result in a raised ratio of energy emission to energy absorption of the area, le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taymyr Peninsula
The Taymyr Peninsula (russian: Таймырский полуостров, Taymyrsky poluostrov) is a peninsula in the Far North of Russia, in the Siberian Federal District, that forms the northernmost part of the mainland of Eurasia. Administratively it is part of the Krasnoyarsk Krai Federal subject of Russia. Geography The Taymyr Peninsula lies between the Yenisei Gulf of the Kara Sea and the Khatanga Gulf of the Laptev Sea. Lake Taymyr and the Byrranga Mountains are located within the vast Taymyr Peninsula. Cape Chelyuskin, the northernmost point of the Afro-Eurasian continent, is located at the northern end of the Taymyr Peninsula. Population The Nenets people, also known as ''Samoyeds'', are an indigenous people in northern arctic Russia, and some live at the Taymyr Peninsula. The Nganasan people are an indigenous Samoyedic people inhabiting central Siberia, including the Taymyr Peninsula. In the Russian Federation, they are recognized as being one of the Indigenous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy
Stratigraphy is a branch of geology concerned with the study of rock (geology), rock layers (Stratum, strata) and layering (stratification). It is primarily used in the study of sedimentary rock, sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith (geologist), William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of Stratum, strata or rock layering and the importance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Quaternary
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.Oxford University Press – Why Geography Matters: More Than Ever (book) – "Holocene Humanity" section https://books.google.com/books?id=7P0_sWIcBNsC The Holocene corresponds with the rapid proliferation, growth and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global sign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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