Oases are often the only places in deserts that support crops and permanent habitation. Underground channels carry water from nearby mountains into the Turpan Depression of China. If the channels were not covered, the water would evaporate quickly when it reached the hot, dry desert land. Soils Soils that form in arid climates are predominantly mineral soils with low organic content. The repeated accumulation of water in some soils causes distinct salt layers to form.
Caliche is a reddish-brown to white layer found in many desert soils.
Caliche commonly occurs as nodules or as coatings on mineral grains formed by the complicated interaction between water and carbon dioxide released by plant roots or by decaying organic material. Plants Sparse, very dry, single-species vegetation in Death Valley, California. Some store water in their leaves, roots, and stems. Other desert plants have long tap roots that penetrate the water table, anchor the soil, and control erosion. The stems and leaves of some plants lower the surface velocity of sand-carrying winds and protect the ground from erosion.