Soil organisms

Overview

The soil is home to circa 59% of the world's biodiversity. The links between soil organisms and soil functions are complex. The interconnectedness and complexity of this soil 'food web' means any appraisal of soil function must necessarily take into account interactions with the living communities that exist within the soil. Soil organisms break down organic matter, making nutrients available for uptake by plants and other organisms. The nutrients stored in the bodies of soil organisms prevent nutrient loss by leaching, in particular for nitrogen and phosphorus. Microbial exudates act to maintain soil structure, and earthworms are important in bioturbation. However, critical aspects about how these populations function and interact are unclear. The discovery of glomalin in 1996 indicates that the knowledge to correctly answer some of the most basic questions about the biogeochemical cycle in soils is lacking. There is much work ahead to gain a better understanding of the ecological role of soil biological components in the biosphere.