Arctic tundra is located in the northern hemisphere that encircles the north pole and extends to south of the coniferous forests of the taiga. The tundra covers about one fifth of the land surface found on Earth. Tundra is the coldest and driest of all the biomes. Tundra comes from the Finnish word tunturia, meaning treeless plain. The ground is subject to permafrost (land that is permanently frozen), but the surface layer melts in the summer. Soil conditions are poor, being marshy and waterlogged. Little plant life can survive. Only grasses, mosses, lichens and dwarf shrubs exist in this area.