Palearctic

Palearctic
Name	Palearctic
Region	Europe, North Africa, Asia north of the Himalayas
Area km2	20000000
Countries	France, Spain, United Kingdom, Germany, Russia, China, Mongolia, Kazakhstan, Saudi Arabia, Turkey, Morocco, Algeria, Egypt
Biomes	temperate broadleaf and mixed forests, boreal forest, Mediterranean forests, deserts and xeric shrublands, montane grasslands and shrublands
Conservation	Convention on Biological Diversity, Ramsar Convention

Palearctic is the largest of the Earth's terrestrial biogeographic realms, encompassing much of Europe, North Africa, and temperate and arctic Asia. It includes a wide range of landscapes from the Atlantic coasts of Portugal and Ireland through the steppes of Ukraine and Kazakhstan to the tundra of Siberia and the deserts of Arabia and Iran. The realm has been a focal area for research by institutions such as the Natural History Museum, London, the Smithsonian Institution, and the Russian Academy of Sciences and figures including Alfred Russel Wallace and Ernst Haeckel influenced its biogeographic conceptualization.

Definition and scope

The realm is defined in zoogeography and phytogeography as the terrestrial region north of the Sahara Desert and south of the Arctic Ocean that excludes the Nearctic and merges with the Indomalayan realm across complex transition zones at the Himalayas and the Tibet Plateau. Major taxonomic works by Philip Sclater and later syntheses by the World Wildlife Fund and the International Union for Conservation of Nature treat it as a coherent unit for vertebrate and plant distributions. Political entities within its scope include European Union members such as Italy and Poland as well as Asian states like India's northern reaches and the Russian Federation. Paleobiogeographic boundaries were debated in the works of Alfred Wegener and in modern treatments by the Paleobiology Database and the International Biogeography Society.

Geographical boundaries and subdivisions

Geographically the realm spans from the Atlantic islands of Iceland and the Azores (biogeographically linked) eastwards across Great Britain and the Scandinavian Peninsula to the Kamchatka Peninsula, and south to include the Mediterranean shores of Greece and Tunisia and the deserts of the Arabian Peninsula. Subdivisions commonly recognized are Western Europe, Eastern Europe and Western Siberia, Central Siberia, the Russian Far East, the Mongolian steppe, the Iranian Plateau, and the Mediterranean and Macaronesian provinces. Ecoregional classification by the European Environment Agency and the World Wildlife Fund outlines provinces such as the Sarmatic mixed forests, the Pontic–Caspian steppe, the Taimyr tundra, the Altai montane forests, and the Atlas Mountains woodlands. Historical geopolitical frontiers like the Treaty of Tordesillas did not alter biogeographic boundaries, whereas paleoclimatic events associated with the Last Glacial Maximum shifted ecotones substantially.

Climate and biomes

Climatically the realm includes Arctic, subarctic, temperate, continental, Mediterranean, and arid regimes influenced by systems studied by the Intergovernmental Panel on Climate Change and regional agencies such as Météo-France and the Russian Federal Service for Hydrometeorology and Environmental Monitoring. Major biomes include boreal forests (taiga), temperate broadleaf and mixed forests seen in France and Germany, Mediterranean forests and scrub across Spain and Turkey, temperate grasslands exemplified by the Eurasian Steppe, and deserts and xeric shrublands in Saudi Arabia and Mongolia. Mountainous regions such as the Alps, the Caucasus Mountains, and the Himalayas host montane and alpine biomes with endemic assemblages noted in publications by the International Union for Conservation of Nature and the Royal Society.

Flora and fauna

Floral assemblages feature temperate genera such as Quercus (oaks), Fagus (beeches), and Betula (birches) alongside steppe grasses like Stipa and Mediterranean sclerophylls including Olea europaea (olive). Faunal elements include megafauna and charismatic taxa historically present or extant: Ursus arctos (brown bear), Panthera pardus (leopard) populations persisting in Caucasus refugia, Canis lupus (wolf), and migratory birds linking this realm to Africa and South Asia, studied by organizations such as the Royal Society for the Protection of Birds and the BirdLife International. Invertebrate biodiversity includes Lepidoptera documented by entomologists at the Natural History Museum, London and mollusks recorded in the World Register of Marine Species for coastal provinces. Domesticated species with origins or long histories here include Equus ferus caballus (horse) lines associated with the Pontic–Caspian steppe and early cereal domestication sites near Jericho and the Fertile Crescent.

Paleontology and biogeographic history

The palaeontological record includes Pleistocene megafaunal assemblages such as Mammuthus primigenius (woolly mammoth), Coelodonta antiquitatis (woolly rhinoceros), and steppe-adapted grazers documented at sites like La Brea Tar Pits analogues in Eurasia and stratigraphic sequences curated by the Natural History Museum, Vienna and the Russian Academy of Sciences. Biogeographic history is shaped by repeated glacial–interglacial cycles, faunal exchanges across the Bering Land Bridge with the Nearctic, and dispersal corridors through the Turkish Straits and Iranian Plateau. Influential theories by Charles Darwin and later quantitative analyses in journals from the Royal Society and the Proceedings of the National Academy of Sciences illuminate vicariance, refugia dynamics, and postglacial recolonization patterns.

Human interaction and conservation

Human civilizations from Ancient Greece and Roman Empire to Mongol Empire and modern nation-states have transformed landscapes via agriculture, urbanization, and infrastructure projects like the Trans-Siberian Railway and the Suez Canal, altering habitats and migration routes noted by conservationists at IUCN and UNESCO World Heritage Centre. Contemporary conservation efforts include protected areas under national agencies such as the Ministry of Environment, France and international frameworks like the Natura 2000 network and Ramsar Convention wetlands. Threats include habitat fragmentation, invasive species incidents studied by the European Commission, and climate change impacts modeled by the Intergovernmental Panel on Climate Change, prompting initiatives by NGOs including WWF International and Conservation International to safeguard endemic taxa and ecoregions.

Category:Biogeographic realms