Phytochorion
From Wikipedia, the free encyclopedia
A Phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phtyochoria 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.
[edit] 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. phtyochoria 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, 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.[1]
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.
[edit] Floristic kingdoms
Botanist Ronald Good identified six floristic kingdoms (Boreal, 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 provinces. The Paleotropical kingdom is divided into three subkingdoms, which are each subdivided into floristic provinces. Each of the other five kingdoms are subdivided directly into provinces. There are a total of 37 floristic provinces. Almost all provinces are further subdivided into floristic regions.
Armen Takhtajan, 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.
[edit] Takhtajan's floristic provinces
|
||||||||||||||||||||
[edit] Holarctic Kingdom
.png/300px-Floristic_regions_in_Europe_(english).png)
[edit] I. Circumboreal Region
- 1 Arctic
- 2 Atlantic Europe
- 3 Central Europe
- 4 Illyria or Balkan
- 5 Pontus Euxinus
- 6 Caucasus
- 7 Eastern Europe
- 8 Northern Europe
- 9 Western Siberia
- 10 Altai-Sayan
- 11 Central Siberia
- 12 Transbaikalia
- 13 Northeastern Siberia
- 14 Okhotsk-Kamchatka
- 15 Canada incl. Great Lakes
[edit] II. Eastern Asiatic Region
- 16 Manchuria
- 17 Sakhalin-Hokkaidō
- 18 Japan-Korea
- 19 Volcano-Bonin
- 20 Ryūkyū or Tokara-Okinawa
- 21 Taiwan
- 22 Northern China
- 23 Central China
- 24 Southeastern China
- 25 Sikang-Yuennan
- 26 Northern Burma
- 27 Eastern Himalaya
- 28 Khasi-Manipur
[edit] III. North American Atlantic Region
- 29 Appalachian Province (forested areas extending east to include the piedmont and west to the start of the prairies)
- 30 Atlantic and Gulf Coastal Plain
- 31 North American Prairies
[edit] IV. Rocky Mountain Region
- 32 Vancouver
- 33 Rocky Mountains
[edit] V. Macaronesian Region
- 34 Azores
- 35 Madeira
- 36 Canaries
- 37 Cape Verde
[edit] VI. Mediterranean Region
- 38 Southern Morocco
- 39 Southwestern Mediterranean
- 40 South Mediterranean
- 41 Iberia
- 42 Baleares
- 43 Liguria-Tyrrhenia
- 44 Adriatic
- 45 East Mediterranean
- 46 Crimea-Novorossijsk
[edit] VII. Saharo-Arabian Region
- 47 Sahara
- 48 Egypt-Arabia
[edit] VIII. Irano-Turanian Region
- 49 Mesopotamia
- 50 Central Anatolia
- 51 Armenia-Iran
- 52 Hyrcania
- 53 Turania or Aralo-Caspia
- 54 Turkestan
- 55 Northern Baluchistan
- 56 Western Himalaya
- 57 Central Tien Shan
- 58 Dzungaria-Tien Shan
- 59 Mongolia
- 60 Tibet
[edit] IX. Madrean Region
- 61 Great Basin
- 62 California
- 63 Sonora
- 64 Mexican Highlands
[edit] Paleotropical Kingdom
[edit] X. Guineo-Congolian Region
- 65 Upper Guinea
- 66 Nigeria-Cameroon
- 67 Congo
[edit] XI. Usambara-Zululand Region
- 68 Zanzibar-Inhambane
- 69 Tongoland-Pondoland
[edit] XII. Sudano-Zambezian Region
- 70 Zambezi
- 71 Sahel
- 72 Sudan
- 73 Somalia-Ethiopia
- 74 South Arabia
- 75 Socotra
- 76 Oman
- 77 South Iran
- 78 Sindia
[edit] XIII. Karoo-Namib Region
- 79 Namibia
- 80 Namaland
- 81 Western Cape
- 82 Karoo
[edit] XIV. St.Helena and Ascension Region
- 83 St. Helena and Ascension
[edit] XV. Madagascan Region
- 84 Eastern Madagascar
- 85 Western Madagascar
- 86 Southern and Southwestern Madagascar
- 87 Comoro
- 88 Mascarenes
- 89 Seychelles
[edit] XVI. Indian Region
[edit] XVII. Indochinese Region
- 95 South Burma
- 96 Andamans
- 97 South China
- 98 Thailand
- 99 North Indochina
- 100 Annam
- 101 South Indochina
[edit] XVIII. Malesian Region
- 102 Malaya
- 103 Borneo
- 104 Philippines
- 105 Sumatra
- 106 South Malesia
- 107 Celebes
- 108 Moluccas and West New Guinea
- 109 Papua
- 110 Bismarck Archipelago
[edit] XIX. Fijian Region
- 111 New Hebrides
- 112 Fiji
[edit] XX. Polynesian Region
- 113 Micronesia
- 114 Polynesia
[edit] XXI. Hawaiian Region
- 115 Hawaii
[edit] XXII. Neocaledonian Region
- 116 New Caledonia
[edit] Neotropical Kingdom
[edit] XXIII. Caribbean Region
- 117 Central America
- 118 West Indies
- 119 Galápagos Islands
[edit] XXIV. Region of the Guayana Highlands
- 120 Guayana
[edit] XXV. Amazonian Region
[edit] XXVI. Brazilian Region
[edit] XXVII. Andean Region
- 128 Northern Andes
- 129 Central Andes
[edit] South African Kingdom
[edit] XXVIII. Cape Region
- 130 Cape Province
[edit] Australian Kingdom
[edit] XXIX. Northeast Australian Region
- 131 North Australia
- 132 Queensland
- 133 Southeast Australia
- 134 Tasmania
[edit] XXX. Southwest Australian Region
[edit] XXXI. Central Australian or Eremaean Region
- 136 Eremaea
[edit] Antarctic Kingdom
[edit] XXXII. Fernandezian Region
- 137 Juan Fernández
[edit] XXXIII. Chile-Patagonian Region
- 138 Northern Chile
- 139 Central Chile
- 140 Pampas
- 141 Patagonia
- 142 Tierra del Fuego
[edit] XXXIV. Region of the South Subantarctic Islands
[edit] XXXV. Neozeylandic Region
- 145 Lord Howe
- 146 Norfolk
- 147 Kermadec
- 148 Northern New Zealand
- 149 Central New Zealand
- 150 Southern New Zealand
- 151 Chatham
- 152 New Zealand Subantarctic Islands
[edit] References
- ^ glossary from Edited by A. Barrie Low and A. (Tony) G. Rebelo from contributions by George J. Bredenkamp, J. Ed Granger, M. Timm Hoffman, Roy A. Lubke, Bruce Mckenzie, A. (Tony) Rebelo, & Noel van Rooyen (February 1998). Vegetation of South Africa, Lesotho and Swaziland: A companion to the Vegetation Map of South Africa, Lesotho and Swaziland. Department of Environmental Affairs and Tourism, Pretoria.
- Good, Ronald, 1947. The Geography of Flowering Plants. Longmans, Green and Co, New York
- Takhtajan, Armen, 1986. Floristic Regions of the World. (translated by T.J. Crovello & A. Cronquist). University of California Press, Berkeley.
