Which biome is commonly characterized by the presence of permafrost?

The tundra biome is commonly characterized by the presence of permafrost, which is a layer of permanently frozen subsoil found beneath the surface layer of soil. This lasting frost typically occurs in regions with very cold temperatures, where the ground remains frozen for significant parts of the year. In the tundra, the growing season is short, and the vegetation consists primarily of low shrubs, grasses, mosses, and lichens that can survive in the harsh climatic conditions.

The presence of permafrost has a significant impact on the ecosystem, as it affects water drainage and soil composition. During the brief summer season, the uppermost layer of soil thaws, creating a saturated condition that can support certain plant life, but the underlying permafrost restricts root growth. This biome is typically found in arctic and alpine regions, where extreme cold is prevalent.

Other biomes, such as high altitude coniferous forests, cold deserts, and high latitude temperate forests, do not have the same consistent permafrost layer as a defining characteristic, making tundra the correct choice in this context. The presence of permafrost is a fundamental aspect distinguishing tundra from these other ecosystems.