Soil Fauna: Linking Different Levels of the Ecological Hierarchy

Abstract

Soil fauna play a significant role in ecosystem-level processes in terrestrial ecosystems through their interaction with the microbial community and alteration of the physical environment. Analyses of soil fauna populations and communities can provide important information on nutrient cycling processes. Four examples demonstrate the utility of this approach. First, analyses of nematode and microarthropod community trophic structure in agroecosystems help to identify the underlying mechanism of why nutrient cycling rates are different under different management practices. Second, by combining earthworm population growth rates and estimates of community secondary production, the amount of nitrogen flux through earthworm biomass in an agroecosystem is estimated. Third, analyses of soil fauna communities in the rhizosphere of pine trees lead to inferences about nitrogen turnover in the rooting zone. Finally, analyses of the trophic structure of soil nematode and microarthropod communities provide a sensitive indicator of disruption of soil food web structure and function following exposure to chemical pollutants. In terrestrial ecosystems, soil fauna are ideal for conducting studies that link population, community, and ecosystem levels in the ecological hierarchy.