The Millennium Ecosystem Assessment (MA) was called for by the United Nations Secretary-General Kofi Annan in 2000. Initiated in 2001, the objective of the MA was to assess the consequences of ecosystem change for human well-being and the scientific basis for action needed to enhance the conservation and sustainable use of those systems and their contribution to human well-being.

Provisioning services are the products obtained from ecosystems, such as food, water, timber, and fiber.

Regulating services are the benefits obtained from the regulation of ecosystem processes, such as climate regulation, disease control, and water purification.

Cultural services are the non-material benefits people obtain from ecosystems through spiritual enrichment, cognitive development, reflection, recreation, and aesthetic experiences.

Supporting services are those that are necessary for the production of all other ecosystem services. They include nutrient cycling, soil formation, primary production and pollination.

So, nutrient cycling and crop pollination fall under the category of supporting services.