Publication TypeBook Chapter
Year of Publication2002
AuthorsWhitford WG
EditorLal R.(ed.)
Book TitleEncyclopedia of Soil Science
PublisherMarcel Dekker, Inc.
CityColumbus, OH
ARIS Log Number150388
AbstractAnts are among the most ubiquitous insects on the planet. They occur in all biomes except for the extreme polar regions. In the biomes where ants are abundant, they affect many soil processes that contribute to the creation of patch mosaics that characterize the soils and vegetation of many landscapes. The abundance and diversity of soil-nesting ants varies from as high as 7,000 colonies per hectare in tropical savanna to as few as 3-4 colonies per hectare on some periodically flooded, fine-textured soil, desert landscape units. Soil-nesting ants affect critical ecosystem processes, such as nutrient cycling and water redistribution. Ant nest mounds vary from a few centimeters in height and diameter to less than 1 m in height and less than 2 m diameter. Ant nests consist of underground, branched networks of galleries and chambers. Surficial chambers are connected to lower chambers by vertical galleries with branching lateral galleries. Galleries and chambers vary in size and number depending on the species of ant. For example, Lasius neoniger, an abundant ant species in temperate North America, constructs tubular galleries of 1.5-5.0 mm in diameter and chambers of 10-20 mm diameter and 30-50 mm in length. The volume of L. neoniger nests range from 20-250 cm (to the third power) and are confined to the upper 70 cm of soil (3). Other species construct nests to depths ranging from 50 cm to greater than several meters, depending on species-specific behavior, soil type, and landscape position. Soil profile mixing, texture, physical and chemical property modification of mound soils, soil macroporosity, and geomorphological attributes of ant nest mounds vary with species-specific colony longevity, body size, and numbers of workers of a colony, soil type, and landscape position. The pedturbation effects of ants are, therefore, dependent on the species composition of the ant community, geomorphic history, soil properties, and topographic position of a landscape unit. Because most studies of the effects of ants on soils have focused on one or two species, a comprehensive analysis of the combined effects of all ant species on the soils of an ecosystem cannot be made.