Monday, November 13, 2006 - 10:00 AM

Texas Leaf-Cutting Ants: How Fungus Farmers Act as Forest Soil Engineers.

D. Andrew Scott, USDA Forest Service, Southern Research Station, 2500 Shreveport Hwy, Pineville, LA 71360 and Linda Hooper-Bui, Louisiana State Univ, Dept of Entomology, Baton Rouge, LA 70803.

Texas leaf-cutting ants (Atta texana) are unique forest soil engineers in the western Gulf coastal plain.  These ants harvest foliage from trees, shrubs, and other vegetation and carry the material 1 to 2 m into the soil.  In chambers shaped like an upside down bowl, the ants grow fungus on the transported vegetative material and use the fungus for food.  The ant activities cause nutrient and physical property changes to the upper 2 m of soil, thereby causing ecologically important soil change over the landscape.  We studied the nutrient and textural change caused by these ants on four locations in central and western Louisiana and will relate these changes to implications for future tree growth and ecosystem functioning.