This BioProvince (as defined by Armen Takhtajan) includes the northern treeless regions of Europe, Siberia and North America, and all of the islands north of the Arctic Circle including Greenland and Iceland. In the Bering Sea its southern boundary includes the Aleutian Islands and Kodiak Island. The BioProvince extends to the furthest limits of plant growth in the northern Polar Regions with temperatures down to -50°C in parts of northern Siberia (e.g. Verkhoyansk). Arctic lands have developed geologically around the ancient crystalline rocks of the continental shields of North America, Europe and Asia, with geologically more recent lowland plains, low plateaus, and mountain chains between them. The soil is often permenantly frozen (permafrost) and even in summer it rarely thaws down to more than 1 m. For plant growth the mean temperature must be above freezing for at least one month of the year, and in many parts of the Arctic BioProvince the growing season is less than two months. In addition, the High Arctic is characterised by anti cyclonic systems in summer resulting in very little atmospheric moisture and precipitation, but in some of the more oceanic parts, such as Greenland and Iceland, the conditions are often much less severe. The vascular plant flora is, not surprisingly, very poor with no more than about 1000 species in total. Nevertheless, the degree of vascular plant endemism is relatively high numbering about 100 species and there are two endemic genera. These include the circumboreal grass genus, Dupontia (D. fischeri and D. psilosantha) and the Canadian genus, Parrya (P. arctica). In the northwestern islands including Melville Island, D. fischeri can become the dominant grassland species. Among other Arctic flowering plants the one reputed to grow further north than any other species is the non-endemic Saxifraga oppositifolia purple saxifage (see below), having been recorded at Cape Morris Jessup on the north coast of Greenland.
The following accounts for this BioProvince have been written or will be written with particular reference to endemic and locally important species. Accounts available are displayed in green or yellow. Those displayed in red are either in the pipeline or awaiting expert contributions.
|Endemic Vascular Plant Flora|
Saxifraga oppositifolia (Saxifragaceae) a circumpolar, arctic-alpine species and one of the hardiest of High-Arctic plants (Copyright © 2010 Peter Martin Rhind)..