Palearctic

The Palearctic is one of the eight biogeographic realms used to categorize Earth's land based on the distribution of plants and animals. It was originally defined in Wallace’s scheme and is now widely employed in contemporary classifications, such as those used by the World Wide Fund for Nature. The realm encompasses Europe, Asia north of the Himalayas, and the northern part of Africa, including the Mediterranean regions and the Arabian Peninsula.

Geographically, its western boundary extends to the British Isles and western Europe, and its eastern edge reaches the Kamchatka Peninsula, the Russian Far East, and Japan. The southern boundary crosses North Africa and the northern fringe of the Indian subcontinent and the Middle East. The Afrotropical realm lies to the south across the Sahara and Sahel, while the Indomalayan realm adjoins it along the Himalayas.

Climatically, the Palearctic spans a broad range from Arctic tundra in the north to temperate forests, steppes, and deserts in the interior, and Mediterranean-type ecosystems in southern Europe, northern Africa, and the Middle East. Its habitats include tundra, taiga, temperate forests, grasslands, deserts, and alpine zones.

Biogeographers commonly divide the Palearctic into subregions such as Western and Eastern Palearctic, with some schemes recognizing additional divisions like Central or Siberian subregions. The realm hosts a mix of widespread Holarctic lineages and regions of endemism in mountains and southern margins, reflecting a long history of climatic fluctuations and human influence across Eurasia.