What is VAST FLAT TREELESS region in which the subsoil is permanentely frozen?

The vast flat treeless region with permanently frozen subsoil is known as the tundra. This biome is characterized by its cold climate, short growing seasons, and limited vegetation, primarily consisting of mosses, lichens, and low shrubs. The permafrost layer beneath the surface prevents significant root growth, making it challenging for trees to thrive. Tundra regions are typically found in Arctic and subarctic areas.