Which type of soil order in the USDA soil taxonomy is characterized by the presence of permafrost within 200 cm of the soil surface?

💡 Solution & Explanation

Gelisols are defined within the USDA soil taxonomy as mineral soils that contain permafrost within two meters of the soil surface. Other soil orders such as Vertisols contain high percentages of swelling clays, and Spodosols are typical of acidic coniferous forests with sub-surface accumulation of aluminum and organic matter.