Soil-dwelling arthropods: Their diversity and functional roles

Soil-dwelling arthropods are extremely diverse and abundant. Northwest forest soils may support an average of 250,000/m(2). Knowledge of functional roles within the soil ecosystem is limited. Some of the prominent functional groups are fungivores, micro-predators, macro-predators, and shredders. Soil food webs involve complex functions and the basic structure requires a minimum of four components. These components are (1) the living plant root, (2) soil bacteria and fungi, (3) fauna that graze on microbial biomes, and (4) predator fauna. Some critical environmental determinants for ensuring persistence of functional links are described. Three categories of determinants are epigeic habitats, soil surface phenomena, and hypogeic habitats.