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Paul Jaccard
Paul Jaccard (18 November 1868 in Sainte-Croix, Switzerland, Sainte-Croix – 9 May 1944 in Zurich) was a professor of botany and plant physiology at the ETH Zurich. He studied at the University of Lausanne and ETH Zurich (PhD 1894). He continued studies in Paris with Gaston Bonnier. He developed the Jaccard index of similarity (he called it ''coefficient de communauté'') and published it in 1901.Jaccard, P. (1901) Distribution de la flore alpine dans le bassin des Dranses et dans quelques régions voisines. Bulletin de la Société Vaudoise des Sciences Naturelles 37, 241-272. He also introduced the use of the species-to-genus ratio (he called it ''generic coefficient'') in biogeography.Jaccard, P. (1901) Étude comparative de la distribution florale dans une portion des Alpes et des Jura. Bulletin de la Société Vaudoise des Sciences Naturelles 37, 547-579. In the 1920s, Paul Jaccard engaged in a dispute with the Finland, Finnish botanist and phytogeography, phytogeographer Alvar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland across Estonia to the south. Finland covers an area of with a population of 5.6 million. Helsinki is the capital and largest city, forming a larger metropolitan area with the neighbouring cities of Espoo, Kauniainen, and Vantaa. The vast majority of the population are ethnic Finns. Finnish, alongside Swedish, are the official languages. Swedish is the native language of 5.2% of the population. Finland's climate varies from humid continental in the south to the boreal in the north. The land cover is primarily a boreal forest biome, with more than 180,000 recorded lakes. Finland was first inhabited around 9000 BC after the Last Glacial Period. The Stone Age introduced several differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
19th-century Swiss Botanists
The 19th (nineteenth) century began on 1 January 1801 ( MDCCCI), and ended on 31 December 1900 ( MCM). The 19th century was the ninth century of the 2nd millennium. The 19th century was characterized by vast social upheaval. Slavery was abolished in much of Europe and the Americas. The First Industrial Revolution, though it began in the late 18th century, expanding beyond its British homeland for the first time during this century, particularly remaking the economies and societies of the Low Countries, the Rhineland, Northern Italy, and the Northeastern United States. A few decades later, the Second Industrial Revolution led to ever more massive urbanization and much higher levels of productivity, profit, and prosperity, a pattern that continued into the 20th century. The Islamic gunpowder empires fell into decline and European imperialism brought much of South Asia, Southeast Asia, and almost all of Africa under colonial rule. It was also marked by the collapse of the large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1944 Deaths
Events Below, the events of World War II have the "WWII" prefix. January * January 2 – WWII: ** Free France, Free French General Jean de Lattre de Tassigny is appointed to command First Army (France), French Army B, part of the Sixth United States Army Group in North Africa. ** Landing at Saidor: 13,000 US and Australian troops land on Papua New Guinea, in an attempt to cut off a Japanese retreat. * January 8 – WWII: Philippine Commonwealth troops enter the province of Ilocos Sur in northern Luzon and attack Japanese forces. * January 11 ** President of the United States Franklin D. Roosevelt proposes a Second Bill of Rights for social and economic security, in his State of the Union address. ** The Nazi German administration expands Kraków-Płaszów concentration camp into the larger standalone ''Konzentrationslager Plaszow bei Krakau'' in occupied Poland. * January 12 – WWII: Winston Churchill and Charles de Gaulle begin a 2-day conference in Marrakech ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1868 Births
Events January–March * January 2 – British Expedition to Abyssinia: Robert Napier leads an expedition to free captive British officials and missionaries. * January 3 – The 15-year-old Mutsuhito, Emperor Meiji of Japan, declares the ''Meiji Restoration'', his own restoration to full power, under the influence of supporters from the Chōshū and Satsuma Domains, and against the supporters of the Tokugawa shogunate, triggering the Boshin War. * January 5 – Paraguayan War: Brazilian Army commander Luís Alves de Lima e Silva, Duke of Caxias enters Asunción, Paraguay's capital. Some days later he declares the war is over. Nevertheless, Francisco Solano López, Paraguay's president, prepares guerrillas to fight in the countryside. * January 7 – The Arkansas constitutional convention meets in Little Rock. * January 9 – Penal transportation from Britain to Australia ends, with arrival of the convict ship ''Hougoumont'' in Western Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Competitive Exclusion
In ecology, the competitive exclusion principle, sometimes referred to as Gause's law, is a proposition that two species which compete for the same limited resource cannot coexist at constant population values. When one species has even the slightest advantage over another, the one with the advantage will dominate in the long term. This leads either to the extinction of the weaker competitor or to an evolutionary or behavioral shift toward a different ecological niche. The principle has been paraphrased in the maxim "complete competitors can not coexist". History The competitive exclusion principle is classically attributed to Georgy Gause, although he actually never formulated it. The principle is already present in Darwin's theory of natural selection. Throughout its history, the status of the principle has oscillated between ''a priori'' ('two species coexisting ''must'' have different niches') and experimental truth ('we find that species coexisting do have different niches') ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alvar Palmgren
Alvar Palmgren (28 April 1880 – 30 November 1960) was a Finnish botanist and plant ecologist. Palmgren studied botany at the University of Helsinki under professor J.P. Norrlin. He graduated (Fil.kand.) in 1906 and obtained his Ph.D. in 1914. He became docent of botany at the University of Helsinki 1916 and professor of botany at the same university in 1928 (from 1938, the first in the special Swedish-language chair of botany). He retired in 1950. Research Palmgren worked as a systematic botanist with microspecies of ''Taraxacum'', ''Hieracium'' and other genera. As an ecologist, he worked of the nature of plant communities. He supported the ideas of Henry Gleason on the individualistic behaviour of species in community assembly already from the 1920s. Palmgren wrote early accounts on the role of isolation and stochastic events in the distribution of species, while his contemporary biology was largely deterministic.Palmgren, A. (1921) Die Entfernung als pflanzengeographische ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytogeography
Phytogeography (from Greek φυτόν, ''phytón'' = "plant" and γεωγραφία, ''geographía'' = "geography" meaning also distribution) or botanical geography is the branch of biogeography that is concerned with the geographic distribution of plant species and their influence on the earth's surface. Phytogeography is concerned with all aspects of plant distribution, from the controls on the distribution of individual species ranges (at both large and small scales, see species distribution) to the factors that govern the composition of entire communities and floras. Geobotany, by contrast, focuses on the geographic space's influence on plants. Fields Phytogeography is part of a more general science known as biogeography. Phytogeographers are concerned with patterns and process in plant distribution. Most of the major questions and kinds of approaches taken to answer such questions are held in common between phyto- and zoogeographers. Phytogeography in wider sense (or geobot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Botanist
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek word (''botanē'') meaning "pasture", " herbs" "grass", or " fodder"; is in turn derived from (), "to feed" or "to graze". Traditionally, botany has also included the study of fungi and algae by mycologists and phycologists respectively, with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists (in the strict sense) study approximately 410,000 species of land plants of which some 391,000 species are vascular plants (including approximately 369,000 species of flowering plants), and approximately 20,000 are bryophytes. Botany originated in prehistory as herbalism with the efforts of early humans to identify – and later cultivate – edible, med ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biogeography
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area.Brown University, "Biogeography." Accessed February 24, 2014. . Phytogeography is the branch of biogeography that studies the distribution of plants. Zoogeography is the branch that studies distribution of animals. Mycogeography is the branch that studies distribution of fungi, such as mushrooms. Knowledge of spatial variation in the numbers and types of organisms is as vital to us today as it was to our early human ancestors, as we adapt to heterogeneous but geographically predictable environments. Biogeography is an integrative field of inquiry that unites concepts and information from ecology, evolutionary biology, taxonomy, geology, physical geography, palaeontology, and climatology.Dansereau, Pierre. 1957 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sainte-Croix, Switzerland
Sainte-Croix is a municipality in the district of Jura-Nord Vaudois in the canton of Vaud in Switzerland. History Sainte-Croix is first mentioned in 1177 as ''Sancta Crux''. In 1317 it was mentioned as ''Saint Crueyz''. Previously it was known by its German name ''Heilig Kreuz''. Geography Sainte-Croix has an area, , of . Of this area, or 41.1% is used for agricultural purposes, while or 49.6% is forested. Of the rest of the land, or 7.0% is settled (buildings or roads), or 0.3% is either rivers or lakes and or 1.8% is unproductive land.Swiss Federal Statistical Office-Land Use Statistics 2009 data accessed 25 March 2010 Of the built up area, housing and buildings made up 3.6% and transportation infrastructure made up 2.6%. Out of the fores ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jaccard Index
The Jaccard index, also known as the Jaccard similarity coefficient, is a statistic used for gauging the similarity and diversity of sample sets. It was developed by Grove Karl Gilbert in 1884 as his ratio of verification (v) and now is frequently referred to as the Critical Success Index in meteorology. It was later developed independently by Paul Jaccard, originally giving the French name ''coefficient de communauté'', and independently formulated again by T. Tanimoto. Thus, the Tanimoto index or Tanimoto coefficient are also used in some fields. However, they are identical in generally taking the ratio of Intersection over Union. The Jaccard coefficient measures similarity between finite sample sets, and is defined as the size of the intersection divided by the size of the union of the sample sets: : J(A,B) = = . Note that by design, 0\le J(A,B)\le 1. If ''A'' intersection ''B'' is empty, then ''J''(''A'',''B'') = 0. The Jaccard coefficient is widely used in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
