Our soils support our planet's biodiversity and they host a quarter of the total

Soil is one of nature's most complex ecosystems and one of the most diverse habitats on earth: it contains a myriad of different organisms, which interact and contribute to the global cycles that make all life possible. In fact, nowhere in nature are species so densely packed as in soil communities: over 1000 species of invertebrates may be found in a single m² of forest soils.

What is biodiversity?

Biological diversity or 'biodiversity' is described as "the variability among living organisms from all sources, whether terrestrial, aquatic or marine". It includes the diversity within species (genetic diversity), between species (organism diversity) and of ecosystems (ecological diversity).

Why are soil organisms so important?

Soil organisms perform numerous vital functions in the soil ecosystem which have direct interactions with the biological, atmospheric and hydrological systems. They are responsible for nutrient cycling, regulating the dynamics of soil organic matter, soil carbon sequestration and greenhouse gas emissions, modifying soil physical structure and water regimes and enhancing plant health, among others.

The interactions between soils organisms with one another and with plants and animals in the ecosystem form a complex web of ecological activity called the soil food web.

These functions and interactions constitute an important resource for the sustainable management of agricultural systems.

How does agriculture impact on biodiversity?

Our agricultural systems clearly affect soil organisms, including their activities and their biodiversity. For example, clearing forested land or grassland for cultivation or the overuse/mis-use of agro-chemicals affect the soil environment and drastically reduce the number and species of soil organisms. A reduction in the number of plant species with different rooting systems, in the quantity and quality of plant residues, or in soil organic matter content limits the range of habitats and foods for soil organisms.

FAO in action: improving biological soil management

Sustainable land management practices such as organic farming, zero-tillage, crop rotations and conservation agriculture are central to ensuring soils health while sustainably increasing farm productivity. Adopting an ecosystem approach which takes into account land, water and living resources is vital to preserving and boosting biodiversity.

For example, Liberation, an EU-funded research project of nine universities and FAO, aims to link farmland biodiversity to ecosystem services for effective ecofunctional intensification.

Biodiversity is linked to soil health, which, is in turn, linked to food quality and quantity. Preserving and boosting biodiversity is imperative to enhancing soil health thus ensuring a productive food system, improved rural livelihoods and a healthy environment.

Related links

Fact sheet: Soils support our planet's biodiversity and they host a quarter of the total