Lichens are present throughout the monument and preserve at Aniakchak. Since the majority of the unit is composed of wet, alpine, or moist tundra, lichen thrive. Lichens were able to prosper first after the 1931 eruption that covered the area with ash. Lichen multiplied and expanded, and as they died they left organic matter to mix with erosive sands to form a fine layer of thin cryptogamic soil on which mosses began to grow. Slowly these pioneer associations worked with the rain and the winds to create a soil hospitable to other flora. The succession process is still fragile and in its beginning stages.