Ant (Formica cinerea) Pedoturbation in a Prairie Soil

Abstract

Active and recently active mounds made by the ant (Formica cinerea montana Emery) number 1,531 ha and occupy 1.7% of the area of the surface of Tama silt loam in a prairie remnant in southwestern Wisconsin. The average volume of an ant mound is 0.02 m³, of which about 12% is occupied by channels and chambers. The mineral soil in the upper half to two‐thirds of a representative mound consists about 85% of B horizon material, judging by soil color, content of clay, and oriented argillans. Unusually high contents of available K and P in the mound are probably a result of concentration by the ants of organic materials, particularly those derived from plant sap from aphids; of rapid mineralization of organic matter; and by addition by the ants of B horizon material. Upward movement of soil material by ants could account for the relatively high clay content of the A horizon of Tama silt loam in southwestern Wisconsin, as contrasted with that of the A horizon of the comparable nearby forest soil.