The Convention on Biological Diversity defines Biological Diversity as “the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems” and includes genetic diversity.
An ecosystem is a dynamic complex of plants, animals, and micro-organisms communities and the non-living environment interacting as a functional unit.
The Millennium Ecosystem Assessment defines ecosystem services as the benefits (and occasionally disbenefits) that people obtain from ecosystems.

They include the following:

  • provisioning services such as supply of food, water, timber and fibre
  • regulating services such as the regulation of climate, floods, disease, wastes and water quality
  • cultural services such as recreational, aesthetic, and spiritual benefits
  • supporting services such as soil formation, photosynthesis and nutrient cycling.

See a full list of ecosystem services, as defined by The Economics of Ecosystems and Biodiversity or “TEEB” initiative.

The IPBES Conceptual Framework models in a simplified way the complex interactions between the natural world and human societies, and recognizes and considers a range of knowledge systems.