Southeast Alaska has an unusual climate that allows a large number of edible plant and edible mushroom species to grow. The area consists primarily of the Tongass National Forest, which is a Temperate rainforest. This rainforest has plenty of precipitation and the temperature remains relatively constant, therefore many plant and fungi species flourish there. On a geological time scale, fairly recently during the Little Ice Age, glaciers were abundant in Southeast Alaska. The ice age's last maximum ended about 10,000 years ago. Once the glaciers retreated, they left behind nutrient-rich sediments. These nutrients in the soil enriched the ecosystem of the area.