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.
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 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 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 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) 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 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.
Botanist Ronald Good (1947) identified six floristic kingdoms (Boreal or Holarctic, Neotropical, Paleotropical, South African, Australian, and Antarctic), 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 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.
António Rodrigo Pinto da Silva (Porto, March 13, 1912 – Lisbon, September 28, 1992), often referred to as A.R. Pinto da Silva or P. Silva, was a Portuguese botanist who distinguished himself as a taxonomist and phytosociologist when he collaborated with Swiss botanist Josias Braun-Blanquet and also with Pierre Dansereau.
His studies on taxonomy and floristic yielded a substantial number of new taxa and a better knowledge about many plants and its nomenclature. He organized the Estação Agronómica Nacional's (National Agronomic Station) herbarium, which he rose from 3000 to almost 100,000 entries. He was a pioneer on ethnobotany studies in Portugal and published several contributions on vernacular nomenclature of Portuguese flora, cultivated plants and popular use of wild plants as food. For half a century he helped archaeologists, having published numerous works on paleoethnobotany, among more than 300 articles, notes and communications published throughout his life both in Portuguese and foreign publications.Biodiversity of Cape Town
Biodiversity of Cape Town is the variety and variability of life within the geographical extent of Cape Town. The terrestrial vegetation is particularly diverse and much of it is endemic to the city and its vicinity. Terrestrial and freshwater animal life is heavily impacted by urban development and habitat degradation. Marine life of the waters immediately adjacent to the city is also diverse, and while also impacted by human activity, the habitats are relatively intact.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. Phytogeography is the branch of biogeography that studies the distribution of plants. Zoogeography is the branch that studies distribution of animals.
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, geology, and physical geography.Modern biogeographic research combines information and ideas from many fields, from the physiological and ecological constraints on organismal dispersal to geological and climatological phenomena operating at global spatial scales and evolutionary time frames.
The short-term interactions within a habitat and species of organisms describe the ecological application of biogeography. Historical biogeography describes the long-term, evolutionary periods of time for broader classifications of organisms. Early scientists, beginning with Carl Linnaeus, contributed to the development of biogeography as a science. Beginning in the mid-18th century, Europeans explored the world and discovered the biodiversity of life.
The scientific theory of biogeography grows out of the work of Alexander von Humboldt (1769–1859), Hewett Cottrell Watson (1804–1881), Alphonse de Candolle (1806–1893), Alfred Russel Wallace (1823–1913), Philip Lutley Sclater (1829–1913) and other biologists and explorers.Ecoregions of Madagascar
The ecoregions of Madagascar, as defined by the World Wildlife Fund, include seven terrestrial, five freshwater, and two marine ecoregions. Madagascar's diverse natural habitats harbour a rich fauna and flora with high levels of endemism, but most ecoregions suffer from habitat loss.Flora of St Helena
The flora of Saint Helena, an isolated island in the South Atlantic Ocean, is exceptional in its high level of endemism and the severe threats facing the survival of the flora. In phytogeography, it is in the phytochorion St. Helena and Ascension Region of the African Subkingdom, in the Paleotropical Kingdom.Great Basin Floristic Province
The Great Basin Floristic Province is a floristic province of the Madrean Subkingdom (floristic region), in the Boreal Kingdom (floristic kingdom). It is located in the Western United States.
A floristic province (otherwise known as a phytochorion) is a concept defined by Ronald Good, in 1947, and refined by Armen Takhtajan, in 1986. A phytochorion is a region on earth that has a relative constant composition of plants. Takhtajan defined the Great Basin Floristic Province to extend well beyond the boundaries of the hydrographically defined Great Basin: it includes the Snake River Plain, the Colorado Plateau, the Uinta Basin, and parts of Arizona north of the Mogollon Rim. The Great Basin phytochorion is distinguished by the presence of Great Basin sagebrush (Artemisia tridentata), and saltbushes in genus Atriplex.The Great Basin floristic province is one geographical division scheme for the Intermountain West, amongst many. Other classifications are proposed by the U.S. Environmental Protection Agency (i.e., the Central Basin and Range ecoregion and the Northern Basin and Range ecoregion), and by the World Wildlife Fund (i.e., Great Basin shrub steppe and Great Basin montane forests)
The larger deserts of the Great Basin Province are: the Great Basin Desert (39,505 square miles (102,320 km2) in Nevada; and the Great Salt Lake Desert (4,000 square miles (10,000 km2) and Escalante Desert (3,270 square miles (8,500 km2) in Utah.Les Baux-de-Provence
Les Baux-de-Provence (French pronunciation: [le bo də pʁɔvɑ̃s]; Occitan: Lei Bauç de Provença) is a French commune in the Bouches-du-Rhône department of the province of Provence in the Provence-Alpes-Côte d'Azur region of southern France. It has a spectacular position in the Alpilles mountains, set atop a rocky outcrop that is crowned with a ruined castle overlooking the plains to the south. Its name refers to its site: in Provençal, a bauç is a rocky spur. The name bauxite (Aluminium ore) is derived from the village name when it was first discovered there by geologist Pierre Berthier in 1821.
It has been named one of the most beautiful villages in France and has over 1.5 million visitors per year although it has only 22 residents in the upper part of the commune and 436 for the whole commune. Inhabitants of the commune are known as Baussencs or Baussenques.List of codes used in the World Geographical Scheme for Recording Plant Distributions
The World Geographical Scheme for Recording Plant Distributions (WGSRPD) is a biogeographical system developed by the international Biodiversity Information Standards (TDWG) organization, formerly the International Working Group on Taxonomic Databases. The system provides clear definitions and codes for recording plant distributions at four scales or levels, from "botanical continents" down to parts of large countries. Current users of the system include the International Union for Conservation of Nature (IUCN), the Germplasm Resources Information Network (GRIN), and the World Checklist of Selected Plant Families (WCSP). Plants of the World Online uses Kew's data sources, and hence also uses the WGSRPD for distributions.Malesia
Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalaya ecozone and Australasia ecozone, and also a phytogeographical floristic region in the Paleotropical Kingdom. It has been given different definitions. The World Geographical Scheme for Recording Plant Distributions split off Papuasia in its 2001 version.Upper Guinea
Upper Guinea is a geographical term used in several contexts:
Upper Guinea (French: Haute-Guinée) is one of the four geographic regions of the Republic of Guinea, being east of Futa Jalon, north of Forest Guinea, and bordering Mali. The population of this region is mainly Malinke.
In a larger sense, it refers to a large plain covering eastern Guinea, Sierra Leone, Liberia and extending into north western Côte d'Ivoire. Mostly forming the upper watershed of the River Niger, it is sparsely populated and is home to the Haut Niger National Park.
Upper Guinea can also refer to the interior part of the wider Guinea region, bordering the Sahel. The interior regions are largely defined by the watersheds of rivers that arise from Fouta Djallon, including the Niger, Senegal, Faleme and others. The term was widely applied during the sixteenth to nineteenth centuries to describe a coastal region and its related hinterland with which Europeans traded.
In biogeography, Upper Guinea refers the region of tropical rainforest extending from southwestern Guinea through Sierra Leone, Liberia, southeastern Guinea, Côte d'Ivoire, and southwestern Ghana. The Dahomey Gap, a drier region of Ghana, Togo, and Benin where the Guinean forest-savanna mosaic extends to the Gulf of Guinea, separates Upper Guinea from the tropical rainforests of Lower Guinea further east. The Upper Guinea forests are also recognized as an endemic bird area.Upper Guinean forests
The Upper Guinean forests is a tropical seasonal forest region of West Africa. The Upper Guinean forests extend from Guinea and Sierra Leone in the west through Liberia, Côte d'Ivoire and Ghana to Togo in the east, and a few hundred kilometers inland from the Atlantic coast. A few enclaves of montane forest lie further inland in the mountains of central Guinea and central Togo and Benin.In the drier interior, the Upper Guinean forests yield to the Guinean forest-savanna mosaic, a belt of dry forests and savannas that lies between the coastal forests and the savannas and grasslands of the Sudan further north. The Dahomey Gap, a region of Togo and Benin where the Guinean forest-savanna mosaic extends to the Atlantic coast, separates the Upper Guinean forests from the Lower Guinean forests to the east, which extend from eastern Benin through Nigeria, Cameroon, and south along the coast of the Gulf of Guinea. The Upper Guinean forests are a Global 200 ecoregion.The Guinean moist forests are much affected by winds from the hot dry area to the north and the cool Atlantic currents. This gives the region a very seasonal climate with over 80 in (203 cm) of rain falling in some areas in the wet season. Over 2000 species of vascular plant have been recorded in the ecoregion, and mammals found here include the chimpanzee (Pan troglodytes), leopard (Panthera pardus), pygmy hippopotamus (Hexaprotodon liberiensis), Ogilby's duiker (Cephalophus ogilbyi), Nimba otter shrew (Micropotamogale lamottei) and the African golden cat (Profelis aurata). There are twenty-one endemic and near-endemic forest birds in the ecoregion of which three, Nimba Flycatcher Melaenornis annamarulae, Gola Malimbe Malimbus ballmanni and Spot-winged Greenbul Phyllastrephus leucolepis are further restricted in distribution to the western forests only.The World Wide Fund for Nature (WWF) designated the Upper Guinean forests, which it calls the Guinean moist forests, as one of its Global 200 critical regions for conservation.
The WWF divides the Upper Guinean forests into three ecoregions:
The Western Guinean lowland forests extend from Guinea and Sierra Leone through Liberia and southeastern Côte d'Ivoire as far as the Sassandra River.
The Eastern Guinean forests extend east from the Sassandra River through Côte d'Ivoire and Ghana to western Togo, with a few isolated enclaves further inland in the highlands of central Togo and Benin.
The Guinean montane forests are found at higher elevations in the Guinea Highlands, which extend through central and southeastern Guinea, northern Sierra Leone, and eastern Côte d'Ivoire.World Geographical Scheme for Recording Plant Distributions
The World Geographical Scheme for Recording Plant Distributions (WGSRPD) is a biogeographical system developed by the international Biodiversity Information Standards (TDWG) organization, formerly the International Working Group on Taxonomic Databases. The WGSRPD standards, like other standards for data fields in botanical databases, were developed to promote "the wider and more effective dissemination of information about the world's heritage of biological organisms for the benefit of the world at large". The system provides clear definitions and codes for recording plant distributions at four scales or levels, from "botanical continents" down to parts of large countries. Current users of the system include the International Union for Conservation of Nature (IUCN), the Germplasm Resources Information Network (GRIN), and the World Checklist of Selected Plant Families (WCSP).
Floristic regions of the world
|South African Kingdom|