Functional biodiversity refers to the set of species that contribute to ecosystem services in an agroecosystem. In other words, it is the biodiversity that is useful to farmers. It provides benefits that can be valued by the farmer through environmental management. The objective is to increase production while limiting interventions in the field. Better soil and plant health promote a more resilient ecosystem.

Each ecosystem is made up of a multitude of “little workers”. For example, the decomposition of organic matter is carried out as much by micro-organisms as by macro-organisms. Their movement through the soil improves the structure of the soil, promoting plant rooting. Mulching the soil provides the nutrients needed by the decomposers. It also retains moisture in the soil and therefore provides a more favorable environment for earthworms. Also, facilities such as hedges, grassy areas, or field borders provide shelter for natural enemies of certain crop pests. It is possible to introduce plants around the cultivated crop, such as the Dittrichia Viscosa in olive groves. This plant attracts parasitoids likely to parasitize the olive fly and therefore has an interest in regulating this pest. Human activity can disturb the proper development of beneficial organisms by degrading the quality of their habitats (modification of the floristic composition, pollution by pesticides). Introducing appropriate plants is essential to prevent harming the services rendered by functional biodiversity.

Functional biodiversity is an important component of agroecological approaches. The farmer can benefit from its functionality by enhancing the interactions between fauna and flora within an agroecosystem. However, the mechanisms behind ecosystem services are complex and are the subject of research, especially in understanding the interactions among different organisms.