The benefits people obtain from ecosystems. These include products obtained from ecosystems (e.g. freshwater, food, fuel, genetic resources, natural medicines, etc.); benefits obtained from the regulation of ecosystem processes ( e.g. water erosion, waste, climate and natural hazards); cultural services (e.g., cultural diversity, educational values, social relations, heritag, etc.) and services that are necessary for the production of other ecosystem services (e.g. primary production, nutrient cycling, and water cycling). (Source: Millenium Ecosystem Assessment, 2005, Island Press, Washington D.C.)