fao.org/soils-2015

©FAO - April 2015

& BIODIVERSITY& BIODIVERSITYSOILSSOILS

#IYS2015

When these diverse soil organisms interact with one another and withthe plants and animals in the ecosystem, they form a complex web of ecological activity.

Soil is one of nature’s most complex ecosystems: it contains a myriad of organismswhich interact and contribute to the global cycles that make all life possible.

SOIL BIODIVERSITY AND AGRICULTURE

ProtozoaBacteria

FungiMycorrhizal

and saprophytic

NematodesRoot-feeders

ArthropodsPredators

NematodesPredators

Organic MatterWaste, residue and

metabolites from plants,animals and microbes

PlantsShoots and roots Birds

Animals

ArthropodsShredders

NematodesFungal and bacterial

feeders

ProtozoaAmoebe, flagellates

and ciliates

Firsttrophic level

Photosynthesizers

Secondtrophic level

Decomposers, mutualists,pathogens, parasites,

root-feeders

Thirdtrophic level

Shredders, predators,grazers

Fourthtrophic levelHigher levelpredators

Fifth and highertrophic levels

Higher levelpredators

Over 1000 species of invertebrates

may be found in 1 m² of forest soils.

A typical healthy soil might contain:

SOILS HOST A QUARTEROF OUR PLANET’S BIODIVERSITY

hundredsof species of fungi

thousands of speciesof bacteria & actinomycetes

nematodes 20-30 species of mites

earth worms

50-100 species of insects

Regulation of soilhydrological processes

Maintenanceof soil structure

Gas exchanges andcarbon sequestration

co2

o2

THE SOIL FOOD WEB

Suppression of pests, parasites and diseases

Decompositionof organic matter

Soil detoxification

Nutrient cycling

Symbiotic and asymbiotic relationships with plants and their roots

Plant growth control

Sources of foodand medicines

Agricultural systems and agro-ecological practices such as:agroecology, agroforestry, conservation agriculture, organicfarming and zero-tillage can sustainably increase farm

productivity without degrading the soil and water resources.

The overuse or misuse of agro-chemicalshas resulted in environmental degradation,

particularly of soil and water resources.

Clearing forested land or grasslandfor cultivation a�ects the soil environment

and drastically reduces the numberand species of soil organisms.

Soil organisms are responsible for performing vital functions in the soil ecosystem:

Biodiversity is essential for food security and nutrition.

vertebrate animals