Aquic and peraquic moisture regimes are characterized by elevated groundwater levels. Peraquic moisture regimes occur when groundwater is always at or near the soil surface. Aquic moisture regimes are reducing and because of saturation are nearly free of dissolved oxygen during the growing season. The presence of sulfidic material is indicative of permanently saturated soil conditions. Reducing conditions are recognizable in the field using a test kit.
Color is a most useful indicator for hydric mineral soil.
Mottling occurs where the water table fluctuates periodically. Longer periods of soil saturation and anaerobic conditions, followed by aerobic conditions, turns manganese ions into oxides which are deposited as concretions. Streaking of subsurface horizons occurs as organic matter is moved downward through sandy layers by a falling water table. As a transitional environment between aquatic and terrestrial systems, wetlands provide unique functions and multiple values. As awareness of unique wetland values increases, humans are discovering more potential uses for wetlands.