The northern coniferous forests(taiga) extend in broad bands across North America and Eurasia. The northern coniferous forest, also known as boreal forest and Taiga, a Russian word that recognizes the swampy nature of much of this forest in the summer, lies to the south of the tundra and to the north of deciduous forests and grasslands. There is no comparable zone in the southern hemisphere, probably because there is little land area there with the proper climate (cold temperatures in the southern hemisphere being moderated by close proximity to the sea; at high latitudes in the southern hemisphere most land is relatively close to the ocean, unlike the northern hemisphere. Also, circulation of the oceans in the southern hemisphere is not blocked by the continental land masses to the same extent as it is in the north. The northern coniferous forest, or taiga, is the largest terrestrial biome on Earth.