Circumboreal Region
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The Circumboreal Region in phytogeography is a floristic region within the Holarctic Kingdom in Eurasia and North America, as delineated by such geobotanists as Josias Braun-Blanquet and Armen Takhtajan.
It is the largest floristic region in the world by area, comprising most of Canada, Alaska, Europe, Caucasus and Russia, as well as North Anatolia (as the southernmost part of the region) and parts of northern New England, Michigan, Minnesota, and the Turtle Mountains of North Dakota. Northern portions of the region include polar desert, taiga[1] and tundra biomes. Many geobotanists divide Eurasian and North American areas into two distinct regions. The continents, however, share much of their boreal flora (e.g. Betula nana, Alnus viridis, Vaccinium vitis-idaea, Arctostaphylos uva-ursi). The flora was severely impoverished during glaciations in the Pleistocene. The region is bordered by Eastern Asiatic, North American Atlantic, Rocky Mountain, Mediterranean and Irano-Turanian Regions.
There are no biological families endemic to this region, but it has endemic genera (e.g. Lunaria, Borodinia, , , Soldanella, Physospermum, Astrantia, Thorella, Pulmonaria, Erinus, Ramonda, Haberlea, Stratiotes, Telekia) and many endemic species, especially in the mountains.
Floristic provinces[]
It is subdivided into a number of floristic provinces. Their delineation is debatable. According to a version of Takhtajan's classification, these are the Arctic, Atlantic European, Central European, Illyrian, Euxinian, Caucasian, Eastern European, Northern European, West Siberian, Altai-Sayan, Central Siberian, Transbaikalian, Northeastern Siberian, Okhotsk-Kamtchatkan and Canadian Provinces.
- Arctic Province (Greenland, Iceland, northern treeless parts of Norway, Finland, Russia, Alaska and Canada, all the Arctic Islands), with more than a hundred endemic species (e.g. , Papaver polare, Salix arctica, , , )
- Atlantic European Province (Ireland, United Kingdom, Andorra, parts of Portugal, Spain, France, Belgium, Netherlands, Germany, Denmark and Norway), with two endemic genera (Petrocoptis and Thorella), few dozens of endemic species (e.g. , Ulex europaeus, Genista anglica, )
- Central European Province (Austria, Switzerland, Luxembourg, Poland, Czech Republic, Slovakia, Hungary, parts of Croatia, Slovenia, Italy, France, Belgium, Netherlands, Germany, Denmark, Norway, Sweden, Finland, Russia, Estonia, Latvia, Lithuania, Belarus, Ukraine, Moldova, Romania), with several endemic genera (e.g. Rhizobotrya, Hacquetia, Hladnikia, Berardia) and 10-15% endemic species (e.g. , Dianthus alpinus, Rhododendron hirsutum, , , , , , , Syringa josikaea, , Campanula zoysii, Campanula carpatica, , Leontopodium alpinum, Narcissus poeticus, Narcissus angustifolius, , , Calamagrostis villosa)
- Illyrian Province (Bosnia and Herzegovina, Serbia, Kosovo, Republic of Macedonia, parts of Slovenia, Croatia, Montenegro, Albania, Bulgaria, Greece and Turkey) with several endemic genera (e.g. Haberlea) and many endemic species (e.g. Ramonda heldreichii, Ramonda nathaliae, Ramonda serbica, Picea omorika, Pinus heldreichii, Pinus peuce, Rheum rhaponticum, Aesculus hippocastanum, Forsythia europaea, , , , , , Dioscorea balcanica)
- Euxinian Province (parts of Bulgaria, Turkey, Georgia and Russia around the Black Sea), with two endemic genera ( and ) and many endemic species (e.g. Abies nordmanniana, Epimedium pubigerum, Quercus pontica, Quercus hartwissiana, , , Corylus colchica, , Paeonia wittmanniana, Hypericum bupleuroides, Hypericum xylosteifolium, , , Epigaea gaultherioides, , , Andrachne colchica, , Staphylea colchica, Hedera colchica, , Heracleum mantegazzianum, , , , Trachystemon orientalis, , Gentiana paradoxa, , , Campanula lactiflora, Inula magnifica, , , , ), some endemic species and genera shared with the Caucasian Province (see below).
- Caucasian Province (parts of Russia, Georgia, Armenia and Azerbaijan), with five endemic genera (Pseudovesicaria, Symphyoloma, , Trigonocaryum and Cladochaeta) and many endemic species (e.g. Betula raddeana, , , , , , , , , , , , , , , , , , , , Geranium renardii, , , var. lagodechiana, , , , , Lilium monadelphum, , , Colchicum laetum, , , ), many endemic species and genera shared with the Euxinian Province (e.g. Agasyllis, , Rhododendron caucasicum, Vaccinium arctostaphylos, Daphne pontica, ).
- Eastern European Province (parts of Estonia, Latvia, Lithuania, Russia, Belarus, Ukraine, Moldova and Romania) without endemic genera, with some endemic species (e.g. , , , , , , Sisymbrium wolgense, , , , , , , , )
- Northern European Province (parts of Finland, Sweden, Norway and Russia), without endemic genera, with but few endemic species (e.g. , )
- West Siberian Province (parts of Russia and Kazakhstan), without endemic genera, with few endemic species
- Altai-Sayan Province (Parts of Russia and Mongolia), with one endemic genus (Microstigma) and many endemic species (e.g. , , , , , , , Anemone baicalensis, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , species of Astragalus and Oxytropis)
- Central Siberian Province (parts of Russia) without endemic genera, with but few endemic species
- Transbaikalian Province (Parts of Russia and Mongolia) without endemic genera, with some endemic species (e.g. , , , , , , )
- Northeastern Siberian Province (parts of Russia), with one endemic genus () and many endemic species (e.g. , , , , , , ).
- Okhotsk-Kamchatkan Province (parts of Russia), with one endemic genus () and many endemic species (e.g. , , , , , , , , , , , , ).
- Canadian Province (St. Pierre and Miquelon, parts of Canada and the United States)[2]
See also[]
- Flora of Azerbaijan
- Flora of Canada
- Flora of the Faroe Islands
- Flora of Lithuania
- Flora of Macedonia
- Flora of Romania
- Flora of Svalbard
- List of the vascular plants of Britain and Ireland
- List of the vascular plants of the Karelian Isthmus
Notes[]
Bibliography[]
- C.Michael Hogan. 2011. Taiga. eds. M.McGinley & C.Cleveland. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC
- David Lewis Lentz. 2000. Imperfect balance: landscape transformations in the Precolumbian Americas, Science, 547 pages, page
- Robert F. Thorne. Phytogeography of North America North of Mexico. Flora of North America, Vol. 1, Ch. 6.
- Floristic regions
- Holarctic