Palearctic realm

Palearctic realm The Palearctic realm is the largest of the Earth's eight biogeographic realms, encompassing vast portions of Eurasia and North Africa and linking major historical regions such as Iberian Peninsula, British Isles, Scandinavia, Ural Mountains, Caucasus Mountains, Anatolia, Arabian Peninsula, Siberia, Mongolia, Tibetan Plateau, Himalayas, Karakoram, Altai Mountains, Gobi Desert, Taklamakan Desert, Kazakhstan, Russian Far East, Japan, Korea, China, India's northern fringe, Iran, Iraq, Sahara Desert margins, and parts of North Africa. It links diverse political entities such as the European Union, Russian Federation, People's Republic of China, Kingdom of Saudi Arabia, Republic of India, Kingdom of Morocco and historic regions like Mesopotamia and Persia. The realm's extent underpins major scientific collaborations between institutions including the Natural History Museum, London, Smithsonian Institution, Russian Academy of Sciences, and Chinese Academy of Sciences.

Geography and extent

The Palearctic realm spans continental features from the Atlantic Ocean to the Bering Strait, and from the Arctic Ocean to the Sahara Desert and Himalayas. Major physiographic provinces include the European Plain, the Central Asian steppe, the West Siberian Plain, the Tibetan Plateau, and the island chains of the British Isles and Japanese Archipelago. It contains watershed systems draining into the North Sea, Baltic Sea, Mediterranean Sea, Black Sea, Caspian Sea, Aral Sea, Sea of Japan and East China Sea. Political borders cross ecoregions shared by states like France, Germany, Poland, Ukraine, Kazakhstan, Mongolia, China, Japan and Egypt, and transit corridors such as the Silk Road and Trans-Siberian Railway traverse its landscapes.

Climate and biomes

Climatic regimes range from Arctic Ocean-influenced polar climates in Svalbard and Lapland to Mediterranean climates on the Iberian Peninsula and Levant, continental climates across Siberia and the Mongolian Plateau, and arid climates in the Gobi Desert and Arabian Peninsula. Major biomes include boreal Taiga forests across Finland, Sweden, and Russia; temperate broadleaf and mixed forests in Central Europe, the Balkan Peninsula, Japan, and Korea; Mediterranean woodlands in the Iberian Peninsula, Italy, Greece, and Turkey; temperate grasslands on the Great Steppe and Pannonian Plain; montane ecosystems on the Alps, Carpathians, Caucasus Mountains, and Himalayas foothills; and desert and xeric shrublands in Sahara Desert margins, Iran, and Gobi Desert.

Fauna and flora

Iconic vertebrates include the European bison, Eurasian elk, Brown bear, Gray wolf, Amur tiger, Snow leopard, Przewalski's horse, Saiga antelope, Muskox in Arctic fringes, and migratory birds crossing links such as the East Atlantic Flyway, Mediterranean Flyway, and Central Asian Flyway. Key avifauna includes Whooper swan, Common crane, Eurasian hoopoe, and Eurasian golden oriole. Notable flora assemblages comprise boreal conifers like Scots pine and Norway spruce in Scandinavia and Russia, temperate oaks and beeches across France and Germany, Mediterranean olive and Aleppo pine in Italy and Greece, alpine flora of the Alps and Tibetan Plateau, and xerophytic shrubs in the Iberian Peninsula and Iran. Endemic genera and species have been described by authorities at the Royal Botanic Gardens, Kew, Linnaean Society of London, and the Institute of Zoology, Chinese Academy of Sciences.

Biogeographic history and evolution

Paleobiogeographic processes from the Pleistocene glacial cycles, including repeated ice sheet expansions in North Sea and Baltic regions and refugia in the Iberian Peninsula, Italy, Balkans, and Caucasus Mountains, shaped contemporary distributions. Faunal exchanges via corridors such as the Bering Land Bridge and historical events like the Last Glacial Maximum produced connections with the Nearctic realm and promoted lineage divergence observed in taxa studied by researchers at the Smithsonian Institution and the Natural History Museum, London. Fossil records from sites like Dmanisi, Altai Mountains, and Ulaanbaatar document hominin and megafaunal turnovers, while molecular phylogenetics using data from the Max Planck Institute for Evolutionary Anthropology, University of Cambridge, and Peking University reconstruct speciation and postglacial recolonization patterns.

Conservation and threats

Conservation challenges include habitat loss from agricultural expansion in regions such as the Po Valley, Pannonian Basin, and North China Plain; fragmentation by infrastructure projects like sections of the Trans-Siberian Railway and pipelines through Caucasus Mountains; overexploitation exemplified by historical hunting of European bison and Przewalski's horse; and climate change impacts altering permafrost in Siberia and precipitation regimes affecting the Mediterranean. International conservation responses involve organizations and agreements such as the International Union for Conservation of Nature, the Convention on Biological Diversity, Ramsar Convention, cross-border protected areas including initiatives in the Alps and Carpathians, and rewilding programs supported by institutions like the Zoological Society of London and the Royal Society for the Protection of Birds. Priority actions highlighted by conservationists at BirdLife International and the World Wide Fund for Nature include protected area expansion, habitat restoration in Ebro Delta and Danube Delta, species reintroduction exemplified by programs for the Eurasian lynx and European bison, and policy integration across the European Union and transcontinental partners.

Category:Biogeographic realms