Background: Ecosystem Functions

The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) defines ecosystem functioning as "the flow of energy and materials through the biotic and abiotic components of an ecosystem. It includes many processes such as biomass production, trophic transfer through plants and animals, nutrient cycling, water dynamics and heat transfer" ^[6].

• In more concrete terms, de Groot et al. ^[7] describe ecosystem functions as: the ability of natural components and processes to directly or indirectly provide goods (e.g., timber, fruit, oxygen, water), and services (e.g., pest control, climate regulation) that satisfy human needs.

Further, de Groot et al. ^[7] group ecosystem functions into these four main categories:

Regulation functions:

• This group maintains the ecosystem and biosphere health. It provides many ecosystem services which benefit humans (e.g., clean air, water or soil). These functions generally regulate essential ecological processes, e.g., through bio-geochemical cycles.
• Examples of functions in this group are: gas or climate regulation, disturbance prevention, and water regulation, but also many more.

Habitat functions:

• This group of functions contributes to the conservation of biological and genetic diversity as well as evolutionary processes. They provide refuge and reproduction-habitats to wild flora and fauna.
• The two functions in this group are the refugium and nursery function.

Production functions:

• The functions in this group are the production of a variety of carbohydrate structures by plants and other organisms. These can be used and/or consumed by different species. However, these goods are not limited to food, but can also be e.g., building materials, energy resources (e.g., fuel) or genetic material (for gene editing).
• Functions of this group can, for example, be the production of the already mentioned food or raw materials, but also medicinal or ornamental resources.

Information functions:

• Natural ecosystems contribute to the maintenance of human health. They can provide opportunities for reflection, spiritual enrichment, cognitive development, recreation and aesthetic experience.
• Exemplary functions from this group are recreation and (eco)tourism, scientific and educational information as well as spiritual and historic information, among others.