The Tundra's soil is a small layer of ground above the frozen permafrost. Only small shrubs, grasses, lichens, and flowers grow during the short (50-60 day) growing season. The soil is shallow, preventing large root systems from growing. There hasn't been any evidence of secondary succession in the Tundra. The difference between Primary and Secondary succession is that in Primary there was no soil to work with and it formed over time. In Secondary, the soil is there, but all the plants were cleared from the region.
