Herbivores, decomposers and other soil organisms

Abstract

There are large differences between herbivores, decomposers and other soil organisms, and so their biologies are conventionally treated separately. When considering the movement of ions in the soil-plant system, however, there are features in common which are usefully discussed together. They may be linked by a simple food web as shown in Figure 5.1

• (a) Net mineralisation. In any consumption of organic material by an organism, there are two main fates for the elements contained in it: either to be assimilated into the tissue or to be catabolised and eliminated as ions. A third fate is the elimination of residual organic matter in modified form. Thus all secondary consumption activities tend to release ions into the soil system.