For use in LRRs W, X, and Y.

A mineral layer of 10 percent or more gleyed matrix colors along root channels or other pores and that starts at a depth of 30 cm (12 inches) or less from the soil surface. The matrix has a dominant hue of 5Y or redder.

User Notes: In a soil layer that is becoming anaerobic, reduced conditions will first occur where the soil microbes have an ample supply of organic carbon. Colder soils, such as those in Alaska, normally have a low content of organic carbon, so the microbes will congregate along the channels containing dead roots. Gley colors will first appear along these channels (fig. 20). In a soil layer that is not already dominated by gley colors, break open pieces of the soil and look closely at the root channels. Many of these will be very thin or fine. See if you can observe thin coatings along the channels that match the gley colors listed in the indicator. If they occur, they indicate that the soil experiences anaerobic conditions.