Presentation: introduction Regulation of Microbial Activity and Organic Matter Dynamics by Macroorganisms: Integrating Biological Function in Soil

In the last 4 decades, much research has been directed at understanding the effects of soil macroorganisms (e.g. plants, earthworms) on soil function, i.e. regulation of microbial activity, nutrient release and organic matter turnover, and soil structure formation. In most cases, the effects of macroorganisms involve direct or indirect interactions with soil microorganisms. As their direct interactionsare relatively well studied, recent research has turned to understanding their indirect interactions (through changes in the physical or chemical environment) in soils. Integrating the interactions of macro- and microorganisms across differing scales of both space and time is a major challenge of this research. One common approach involves soil foodwebs. Foodwebs are composed of fauna and microorganisms linked to each other and organic resources in a trophic network. Although the foodweb approach has been used to quantify temporal changes in biological function (e.g. energy flow), it does not usually account for spatial variability in soil. Another common approach involves functional domains, i.e. regions within the soil that originate from or are modified by soil organisms to the extent that they influence th