Acid Leaching

Acid leaching is the soil-forming process in areas where trees predominate. The organic residues (leaves and needles) that accumulate on the soil surface decompose to form soluble (leachable) products. These products include organic acids that remove mineral nutrients from the surface foil layer and carry the finer clay particles down into the subsoil. As a result, the surface soil tends to have few nutrients and is coarse in texture, while the subsoil becomes enriched with clay and less permeable to water and roots. The scientific name for such soils is Luvisolic soils. These soils dominate the boreal forest and foothills natural regions in Alberta.

Department of the Environment. State of the Environment Report, Terrestrial Ecosystems. Edmonton: n.p., 2001. With permission from Alberta Environment.