TheHolarctic realmis abiogeographic realmthat comprises the majority of habitats found throughout the continents in theNorthern Hemisphere. It corresponds to thefloristicBoreal Kingdom. It includes both theNearcticzoogeographical region (which covers most ofNorth America), andAlfred Wallace'sPalearcticzoogeographical region(which coversNorth Africa,Southeast Asia, theIndian subcontinent), and all ofEurasiaexcept for the southernArabian Peninsula.These regions are further subdivided into a variety ofecoregions. Manyecosystemsand the animal and plant communities that depend on them extend across a number of continents and cover large portions of the Holarctic realm. This continuity is the result of those regions shared glacial history.