Key defintions

Ecosystem. An ecosystem is a dynamic complex of plant, animal, and  microorganism communities and the nonliving environment interacting  as a functional unit. Humans are an integral part of ecosystems. Ecosystems  vary enormously in size; a temporary pond in a tree hollow  and an ocean basin can both be ecosystems.

Ecosystem services. Ecosystem services are the benefits people obtain from ecosystems. These include provisioning services such as food and water; regulating services such as regulation of floods, drought, land degradation, and disease; supporting services such as soil formation and nutrient cycling; and cultural services such as recreational, spiritual, religious and other nonmaterial benefits.

Well-being. Human well-being has multiple constituents, including basic material for a good life, freedom of choice and action, health, good social relations, and security. Well-being is at the opposite end of a continuum from poverty, which has been defined as a ‘‘pronounced deprivation in well-being.’’ The constituents of well-being, as experienced and perceived by people, are situation-dependent, reflecting local geography, culture, and ecological circumstances.

 Millennium ecosystem assessment -  2005