A phytochorion , in phytogeography , is a geographic area with a relatively uniform composition of plant species. Adjacent phytochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both regions overlap. The region of overlap is called a vegetation tension zone .
33-519: The Irano-Turanian Region is a floristic region located within the Tethyan Subkingdom of the Holarctic Kingdom . It is divided into 12 floristic provinces according to the work of Armen Takhtajan , a Soviet-Armenian botanist who created a classification system for flowering plants . One of the main characteristics of the region is a great diversity and abundance of species, especially in
66-528: A book was written in French about his life and one of his greatest contributions, the Botanical Garden of Geneva . He is remembered in the plant genera Candollea and Candolleodendron , several plant species like Eugenia candolleana or Diospyros candolleana and the mushroom Psathyrella candolleana . Candollea , a scientific journal that publishes papers on systematic botany and phylotaxonomy,
99-640: A century later demonstrated that "the internal biological clock" indeed exists. De Candolle's descendants continued his work on plant classification; son Alphonse and grandson Casimir de Candolle contributed to the Prodromus Systematis Naturalis Regni Vegetabilis , a catalog of plants begun by Augustin Pyramus de Candolle. Augustin Pyramus de Candolle was born on 4 February 1778 in Geneva , Republic of Geneva , to Augustin de Candolle,
132-939: A close acquaintance of the Portuguese polymath, José Correia da Serra , who was Portuguese ambassador to Paris and who circulated in an international network of thinkers ranging from the Briton Joseph Banks to the Americans Thomas Jefferson and William Bartram , and the French scholars Antoine Laurent de Jussieu and Georges Cuvier . Correia's endorsement of the idea of emphasizing similarity and symmetry in classifying plants influenced de Candolle, who acknowledged as much in his writing. While in Montpellier , de Candolle published his Théorie élémentaire de la botanique (Elementary Theory of Botany, 1813), which introduced
165-719: A different phylogenetic trajectory. The merging of the Cape floristic kingdom with the African realm was based by the low endemism of higher taxonomic ranks, which could be found outside the cape region in the rest of Africa. The final major change is the separation of the Saharo-Arabian realm from the Holarctic kingdom, though they admit the northern boundary is not clear, with flora from the Holarctic being found within this area. After publishing their regions, Dr. Hong Qian criticized Liu et al. for
198-647: A former official, and his wife, Louise Eléonore Brière. His family descended from one of the ancient families of Provence in France, but relocated to Geneva at the end of the 16th century to escape religious persecution. At age seven de Candolle contracted a severe case of hydrocephalus , which significantly affected his childhood. Nevertheless, he is said to have had great aptitude for learning, distinguishing himself in school with his rapid acquisition of knowledge in classical and general literature and his ability to write fine poetry. In 1794, he began his scientific studies at
231-498: A free-running period of leaf opening and closing of approximately 22–23 hours in constant light, significantly less than the approximate 24-hour period of the Earth's light-dark cycles. Since the period was shorter than 24 hours, he hypothesized that a different clock had to be responsible for the rhythm; the shortened period was not entrained—coordinated—by environmental cues, thus the clock appeared to be endogenous. Despite these findings,
264-569: A large number of endemic taxa . Floristic kingdoms are characterized by a high degree of family endemism, floristic regions by a high degree of generic endemism, and floristic provinces by a high degree of species endemism. Systems of phytochoria have both significant similarities and differences with zoogeographic provinces , which follow the composition of mammal families , and with biogeographical provinces or terrestrial ecoregions , which take into account both plant and animal species. The term "phytochorion" (Werger & van Gils, 1976)
297-541: A new classification system and the word taxonomy . Candolle moved back to Geneva in 1816 and in the following year was invited by the government of the Canton of Geneva to fill the newly created chair of natural history. De Candolle spent the rest of his life in an attempt to elaborate and complete his natural system of botanical classification. de Candolle published initial work in his Regni vegetabillis systema naturale , but after two volumes he realized he could not complete
330-449: A number of scientists continued to search for "factor X", an unknown exogenous factor associated with the Earth's rotation that was driving circadian oscillations in the absence of a light dark schedule, until the mid-twentieth century. In the mid-1920s, Erwin Bunning repeated Candolle's findings and came to similar conclusions, and studies that showed the persistence of circadian rhythm in
363-473: A second edition in 1795. The third edition, which bears the name of both Lamarck and de Candolle, was in reality the work of the latter, the former having only lent his name and access to his collection. In 1804, de Candolle published his Essai sur les propriétés médicales des plantes and was granted a doctor of medicine degree by the medical faculty of Paris. Two years later, he published Synopsis plantarum in flora Gallica descriptarum . de Candolle then spent
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#1732884613318396-413: A widely used scheme that builds on Good's work, identified thirty-five floristic regions, each of which is subdivided into floristic provinces, of which there are 152 in all. Critiquing previous attempts for their lack of phylogenetic relationships in the construction of their regions, Liu et al. incorporated distribution data alongside phylogenetic relationships to configure their realms. This led to
429-553: Is especially associated with the classifications according to the methodology of Josias Braun-Blanquet , which is tied to the presence or absence of particular species, mainly in Africa. Taxonomic databases tend to be organized in ways which approximate floristic provinces, but which are more closely aligned to political boundaries, for example according to the World Geographical Scheme for Recording Plant Distributions . In
462-593: The Collège de France in 1802. Lamarck entrusted him with the publication of the third edition of the Flore française (1805–1815), and in the introduction entitled Principes élémentaires de botanique , de Candolle proposed a natural method of plant classification as opposed to the artificial Linnaean method. The premise of de Candolle's method is that taxa do not fall along a linear scale; they are discrete, not continuous. Lamarck had originally published this work in 1778, with
495-589: The Collège de Genève , where he studied under Jean Pierre Étienne Vaucher , who later inspired de Candolle to make botanical science the chief pursuit of his life. He spent four years at the Geneva Academy, studying science and law according to his father's wishes. In 1798, he moved to Paris after Geneva had been annexed to the French Republic. His botanical career formally began with the help of René Louiche Desfontaines , who recommended de Candolle for work in
528-610: The Iranian Plateau . The region's climate is predominantly continental , with most of the precipitation occurring in the winter and spring. This Asia location article is a stub . You can help Misplaced Pages by expanding it . Phytochorion In traditional schemes, areas in phytogeography are classified hierarchically, according to the presence of endemic families, genera or species, e.g., in floral (or floristic , phytogeographic ) zones and regions , or also in kingdoms , regions and provinces , sometimes including
561-523: The Prodromus through his detailed, extensive research and characterization of the plant family Piperaceae . Augustin de Candolle's great-grandson, Richard Émile Augustin de Candolle , was also a botanist. Augustin de Candolle died on 9 September 1841 in Geneva , after being sick for many years. That same year, he was elected as a member of the American Philosophical Society . In 2017,
594-468: The University of Edinburgh , and in the inception of Darwin's theory in 1838 he considered "the warring of the species", adding that it was even more strongly conveyed by Thomas Malthus , producing the pressures that Darwin later called natural selection . In 1839, de Candolle visited Britain and Darwin invited him to dinner, allowing the two scientists the opportunity to discuss the idea. De Candolle
627-499: The herbarium of Charles Louis L'Héritier de Brutelle during the summer of 1798. The position elevated de Candolle's reputation and also led to valuable instruction from Desfontaines himself. de Candolle established his first genus, Senebiera , in 1799. De Candolle's first books, Plantarum historia succulentarum (4 vols., 1799) and Astragalogia (1802), brought him to the notice of Georges Cuvier and Jean-Baptiste Lamarck . de Candolle, with Cuvier's approval, acted as deputy at
660-502: The author, the apparent characteristics of a community (the dominant life-form ), environment characteristics , the fauna associated, anthropic factors or political - conservationist issues. Several systems of classifying geographic areas where plants grow have been devised. Most systems are organized hierarchically, with the largest units subdivided into smaller geographic areas, which are made up of smaller floristic communities, and so on. Phytochoria are defined as areas possessing
693-630: The categories empire and domain . However, some authors prefer not to rank areas, referring to them simply as "areas", "regions" (in a non hierarchical sense) or "phytochoria". Systems used to classify vegetation can be divided in two major groups: those that use physiognomic-environmental parameters and characteristics and those that are based on floristic (i.e. shared genera and species) relationships. Phytochoria are defined by their plant taxonomic composition, while other schemes of regionalization (e.g., vegetation type , physiognomy , plant formations, biomes ) may variably take in account, depending on
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#1732884613318726-540: The classification of eight realms organized into two super-realms and each composed of a number of sub-realms. Differences from Takhtajan's floristic kingdoms mainly focus on emphasizing the uniqueness of certain realms that he had as subdivisions within kingdoms. Two examples are separating some kingdoms into two separate realms, as happened to the Paleotropical and Antarctic kingdoms, reasoning that they have been separated form each other for long enough time to constitute
759-403: The discovery of an evolutionary relationship, de Candolle introduced the concept of homology . De Candolle also made contributions to the field of chronobiology . Building upon earlier work on plant circadian leaf movements contributed by such scientists as Jean-Jacques d'Ortous de Mairan and Henri-Louis Duhamel du Monceau , de Candolle observed in 1832 that the plant Mimosa pudica had
792-539: The idea of "Nature's war", which influenced Charles Darwin and the principle of natural selection . De Candolle recognized that multiple species may develop similar characteristics that did not appear in a common evolutionary ancestor; a phenomenon now known as convergent evolution . During his work with plants, de Candolle noticed that plant leaf movements follow a near-24-hour cycle in constant light, suggesting that an internal biological clock exists. Though many scientists doubted de Candolle's findings, experiments over
825-585: The inclusion of nonnative distributions in their analyses. In response to this, the group cleaned their data to remove nonnative ranges and reassessed their regions. They suggest that the previous inclusion of exotic species did not significantly affect their mapping and found that the cleaned data revealed the same floristic realms. Augustin de Candolle Augustin Pyramus (or Pyrame ) de Candolle ( UK : / k æ n ˈ d ɒ l / , US : / k ɒ̃ ˈ d ɔː l / , French: [kɑ̃dɔl] ; 4 February 1778 – 9 September 1841)
858-476: The largest natural units he determined for flowering plants. Good's six kingdoms are subdivided into smaller units, called regions and provinces. The Paleotropical kingdom is divided into three subkingdoms, which are each subdivided into floristic regions. Each of the other five kingdoms are subdivided directly into regions. There are a total of 37 floristic regions. Almost all regions are further subdivided into floristic provinces. Armen Takhtajan (1978, 1986), in
891-678: The late 19th century, Adolf Engler (1844-1930) was the first to make a world map with the limits of distribution of floras, with four major floral regions (realms). His Syllabus der Pflanzenfamilien , from the third edition (1903) onwards, also included a sketch of the division of the earth into floral regions. Other important early works on floristics includes Augustin de Candolle (1820), Schouw (1823), Alphonse de Candolle (1855), Drude (1890), Diels (1908), and Rikli (1913). Botanist Ronald Good (1947) identified six floristic kingdoms ( Boreal or Holarctic, Neotropical , Paleotropical , South African , Australian, and Antarctic ),
924-555: The next six summers making a botanical and agricultural survey of France at the request of the French government, which was published in 1813. In 1807, he was appointed professor of botany in the medical faculty of the University of Montpellier , where he would later become the first chair of botany in 1810. His teaching at the University of Montpellier consisted of field classes attended by 200–300 students, starting at 5:00 am and finishing at 7:00 pm. During this period, de Candolle became
957-568: The project on such a large scale. Consequently, he began his less extensive Prodromus Systematis Naturalis Regni Vegetabilis in 1824. However, he was able to finish only seven volumes, or two-thirds of the whole. Even so, he was able to characterize over one hundred families of plants, helping to lay the empirical basis of general botany. Although de Candolle's main focus was botany, throughout his career he also dabbled in fields related to botany, such as phytogeography , agronomy , paleontology , medical botany, and economic botany . In 1827, he
990-507: Was a Swiss botanist . René Louiche Desfontaines launched de Candolle's botanical career by recommending him at a herbarium . Within a couple of years de Candolle had established a new genus, and he went on to document hundreds of plant families and create a new natural plant classification system. Although de Candolle's main focus was botany, he also contributed to related fields such as phytogeography , agronomy , paleontology , medical botany, and economic botany . De Candolle originated
1023-608: Was also among the first to recognize the difference between the morphological and physiological characteristics of organs. He ascribed plant morphology as being related to the number of organs and their positions relative to each other rather than to their various physiological properties. Consequently, this made him the first to attempt to attribute specific reasons for structural and numerical relationships amongst organs, and thus to distinguish between major and minor aspects of plant symmetry. To account for modifications of symmetry in parts of different plants, an occurrence that could hinder
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1056-527: Was elected an associated member of the Royal Institute of the Netherlands . Augustin de Candolle was the first of four generations of botanists in the de Candolle dynasty. He married Mademoiselle Torras and their son, Alphonse Pyramus de Candolle , eventually succeeded to his father's chair in botany and continued the Prodromus . Casimir de Candolle , Augustin de Candolle's grandson, also contributed to
1089-615: Was named after de Candolle and his descendants in honor of their contribution to the field of botany. He was a mentor to the French-Mexican botanist Jean-Louis Berlandier and is credited with encouraging Marie-Anne Libert to investigate cryptogamic flora. De Candolle was the first to put forward the idea of "Nature's war", writing of plants being "at war one with another" with the meaning of different species fighting each other for space and resources. Charles Darwin studied de Candolle's "natural system" of classification in 1826 when at
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