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Thorvald Sørensen
Thorvald (Thorwald) Julius Sørensen (4 July 1902 – 21 June 1973) was a Danish botanist and evolutionary biologist. Biography Sørensen was professor at the Royal Veterinary and Agricultural University 1953–1955 and at the University of Copenhagen 1955–1972. He was director of the Copenhagen Botanical Garden and Botanical Museum during the same period. Thorvald Sørensen spent the years 1931–1935, based on Ella Island, studying plants in the then little known North-East Greenland. He published the botanical research of the Three-year Expedition to East Greenland. He also published a doctoral thesis on the annual phenological rhythm of the High Arctic plant species, including the pollination of their flowers (1941). He critically revised the Greenland flora and sorted out taxonomy of a number of difficult taxa, most notably ''Puccinellia''. He carried out a number of studies in the evolutionary biology of plants, such as ''Taraxacum'', ''Capsella bursa-pastoris'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denmark
) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Danish Realm, Kingdom of Denmark , established_title = History of Denmark#Middle ages, Consolidation , established_date = 8th century , established_title2 = Christianization , established_date2 = 965 , established_title3 = , established_date3 = 5 June 1849 , established_title4 = Faroese home rule , established_date4 = 24 March 1948 , established_title5 = European Economic Community, EEC 1973 enlargement of the European Communities, accession , established_date5 = 1 January 1973 , established_title6 = Greenlandic home rule , established_date6 = 1 May 1979 , official_languages = Danish language, Danish , languages_type = Regional languages , languages_sub = yes , languages = German language, GermanGerman is recognised as a protected minority language in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy (biology)
In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a more inclusive group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain, kingdom, phylum (''division'' is sometimes used in botany in place of ''phylum''), class, order, family, genus, and species. The Swedish botanist Carl Linnaeus is regarded as the founder of the current system of taxonomy, as he developed a ranked system known as Linnaean taxonomy for categorizing organisms and binomial nomenclature for naming organisms. With advances in the theory, data and analytical technology of biological systematics, the Linnaean system has transformed into a system of modern biological classification intended to reflect the evolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silene Sorensenis
''Silene sorensenis'', the three-flowered campion or Sorensen's catchfly, is a species of plant in the family Caryophyllaceae. It is found in the tundra of the Canadian Arctic Archipelago, the Northern Russian Far East and Greenland. This species was named after Danish botanist Thorvald Sørensen Thorvald (Thorwald) Julius Sørensen (4 July 1902 – 21 June 1973) was a Danish botanist and evolutionary biologist. Biography Sørensen was professor at the Royal Veterinary and Agricultural University 1953–1955 and at the University of Co ... (1902–1973). References (2000), database, The PLANTS Database External links * sorensenis Flora of Greenland Flora of the Northwest Territories Flora of Nunavut Flora of the Russian Far East {{Caryophyllaceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puccinellia Groenlandica
''Puccinellia'' is a genus of plants in the grass family, known as alkali grass or salt grass. These grasses grow in wet environments, often in saline or alkaline conditions. They are native to temperate to Arctic regions of the Northern and Southern Hemispheres. Selected species ''Puccinellia deschampsioides'' '' Puccinellia macra'' - Wright's alkali grass :List sources : References External linksJepson Manual Treatment {{Taxonbar, from=Q157774 Poaceae genera [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meddelelser Om Grønland
''Meddelelser om Grønland'' ("''Communications on Greenland''") is a Danish scientific periodical which publishes scientific results from all fields of research on Greenland. It was established by Frederik Johnstrup and published as a single series by the Commission for Scientific Investigations in Greenland from 1878 to 1979, with contributions in Danish, German, English or French. In 1979, following the issue of vol. 206, the series was split up into three individually numbered subseries, all published in English: ''Bioscience'', ''Geoscience'', and ''Man & Society''. When publication of the series was handed over to Museum Tusculanum Press Museum Tusculanum Press (Danish: ''Museum Tusculanums Forlag'') is an independent academic press historically associated with the University of Copenhagen, publishing mainly in the humanities, social sciences and theology. It was founded in 1975 as ... in 2008, the original name was revived, now with the official English title ''Monographs o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braya Intermedia
''Braya'' is a genus of plants in the family Brassicaceae. *''Braya alpina'' Sternb. & Hoppe *''Braya fernaldii'' Abbe *''Braya forrestii'' W.W.Sm. *''Braya glabella'' Richardson *''Braya humilis'' (C.A. Mey.) B.L. Rob. *''Braya linearis'' Rouy *''Braya longii'' Fernald *''Braya pilosa'' Hook. *''Braya rosea'' (Turcz.) Bunge *''Braya scharnhorstii'' Regel & Schmalh. *''Braya thorild-wulffii ''Braya thorild-wulffii'', the Greenland northern rockcress, is a plant species native to Greenland, Nunavut the Canadian Northwest Territories, and from the Chukotka Autonomous Okrug of eastern Russia. ''Braya thorild-wulffii'' is an herb up to ...'' Ostenf. References * * External links Brassicaceae genera {{Brassicales-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christen C
To christen is to perform the religious act of baptism. Christen may also refer to: People Surname * Adolf Christen (1811–1883), court actor, theater director and theater manager * Andreas Christen (born 1989), footballer from Liechtenstein * Björn Christen (born 1980), Swiss ice hockey player * Brian Christen (1926–2000), Canadian cricketer * Claudia Christen (born 1973), Swiss designer * Georges Christen (born 1962), Luxembourgian strongman * Mathias Christen (born 1987), footballer from Liechtenstein * Morgan Christen (born 1961), American judge * Siena Christen, German paralympic athlete * Theophil Friedrich Christen (1879–1920), Swiss scientist Given name * Christen Aagaard (1616–1664), Danish poet * Christen Thorn Aamodt (1770–1836), Norwegian priest * Christen Larsen Arneberg (born 1808), Norwegian politician * Christen Thomsen Barfoed (1815–1899), Danish chemist * Christen Berg (1829–1891), Danish politician and editor * Christen Gran Bøgh (1876â ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannes Grøntved
Johannes Grøntved (25 January 1882 – 11 July 1956) was a Danish botanist. He made investigations of flora and vegetation in Denmark, the Faroe Islands, Iceland, Greenland and Estonia. He was editor of The Botany of Iceland from vol. 3 part 2. Selected scientific works * Grøntved, J. (1927) Formationsstatistiske Undersøgelser paa nogle danske Overdrev. Botanisk Tidsskrift 40: 1-71. Used Raunkiær's quantitative method to describe grassland vegetation. The data were later used by Thorvald Sørensen in developing his '' quotient of similarity''. * Grøntved, J. (1927) Die Flora der Insel Wormsö - Ein Beitrag zur Flora Estlands. Dansk Botanisk Arkiv 5 (4). * Grøntved, J. (1927) Die Flora der Insel Runö. Svensk Botanisk Tidskrift 23: 399–460. * Ostenfeld, C.H. & Grøntved, Johs. (1934) The Flora of Iceland and the Færoes. Copenhagen. * Grøntved, J. (1939) Polygonaceernes Udbredelse i Danmark he distribution in Denmark of Polygonaceae Botanisk Tidsskrift 45: 10–58. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grassland
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other 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 Assessment of Global Ecosystems, 2000) * "A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sørensen–Dice Coefficient
The Sørensen–Dice coefficient (see below for other names) is a statistic used to gauge the similarity of two samples. It was independently developed by the botanists Thorvald Sørensen and Lee Raymond Dice, who published in 1948 and 1945 respectively. Name The index is known by several other names, especially Sørensen–Dice index, Sørensen index and Dice's coefficient. Other variations include the "similarity coefficient" or "index", such as Dice similarity coefficient (DSC). Common alternate spellings for Sørensen are ''Sorenson'', ''Soerenson'' and ''Sörenson'', and all three can also be seen with the ''–sen'' ending. Other names include: * F1 score * Czekanowski's binary (non-quantitative) index * Measure of genetic similarity * Zijdenbos similarity index, referring to a 1994 paper of Zijdenbos et al. Formula Sørensen's original formula was intended to be applied to discrete data. Given two sets, X and Y, it is defined as : DSC = \frac where , ''X'', and , ''Y' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ranunculus
''Ranunculus'' is a large genus of about almost 1700 to more than 1800 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups, spearworts and water crowfoots. The genus is distributed in Europe, North America and South America. The familiar and widespread buttercup of gardens throughout Northern Europe (and introduced elsewhere) is the creeping buttercup ''Ranunculus repens'', which has extremely tough and tenacious roots. Two other species are also widespread, the bulbous buttercup ''Ranunculus bulbosus'' and the much taller meadow buttercup ''Ranunculus acris''. In ornamental gardens, all three are often regarded as weeds. Buttercups usually flower in the spring, but flowers may be found throughout the summer, especially where the plants are growing as opportunistic colonizers, as in the case of garden weeds. The water crowfoots (''Ranunculus'' subgenus ''Batrachium''), which grow in still or running water, are sometimes tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsella Bursa-pastoris
''Capsella bursa-pastoris'', known as shepherd's purse because of its triangular flat fruits, which are purse-like, is a small annual and ruderal flowering plant in the mustard family (Brassicaceae). It is native to eastern Europe and Asia minor, but is naturalized and considered a common weed in many parts of the world, especially in colder climates, including British Isles, where it is regarded as an archaeophyte,Preston CD, Pearman DA & Dines TD (2002) New Atlas of the British Flora. Oxford University Press North America and China, but also in the Mediterranean and North Africa. ''C. bursa-pastoris'' is the second-most prolific wild plant in the world, and is common on cultivated ground and waysides and meadows. Scientists have referred to this species as a 'protocarnivore', since it has been found that its seeds attract and kill nematodes as a means to locally enrich the soil. History Pictured and published in 1486. Description ''Capsella bursa-pastoris'' plants grow from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
