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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 some schemes, areas of phytochoria are classified hierarchically, e.g., in Floral (or Floristic, Phytogeographic) Kingdoms, Regions and Provinces, sometimes including the categories Empire and Domain, while others prefer not to rank areas, referring to them simply as "regions" or "phytochoria".〔Linder, Lovett, Mutke, et al. (2005): (A numerical re-evaluation of the sub-Saharan phytochoria ). ''Biologiske Skrifter'' 55: 229-252.〕 The 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 relationships.〔JOLY, C.A., AIDAR, M.P.M., KLINK, C.A., McGRATH, D.G., MOREIRA, A.G., MOUTINHO, P., NEPSTAD, D.C., OLIVEIRA, A.A.; POTT, A.; RODAL, M.J.N. & SAMPAIO, E.V.S.B. 1999. (Evolution of the Brazilian phytogeography classification systems: implications for biodiversity conservation ). Ci. e Cult. 51: 331-348.〕 Phytochoria are defined by their plant taxonomic composition, while other schemes of regionalization (e.g., phytophysiognomies, formations, biomes) may variably take in account, according to the author, the apparent characteristics of a community (the dominant life-form), environment characteristics, the fauna associated, anthropic factors or political-conservationist issues.〔Magno Coutinho, L. (2006) (O conceito de bioma ). ''Acta bot. bras.'' 20(1): 13-23.〕 == Explanation == 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 taxons. 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'' 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.〔(glossary ) from 〕 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Phytochorion」の詳細全文を読む スポンサード リンク
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