Human Health as an Ecosystem Service: A Conceptual Framework

To live in good health and, in many ways, to live at all, people need a wide array of life-support benefi ts that derive from ecosystems. Collectively these are called ecosystem services , a term referring to the conditions and processes through which ecosystems, and the species that make them up, sustain and fulfi ll human life (Ehrlich and Ehrlich 1981 ; Daily 1997 ; Millennium Ecosystem Assessment 2005 ) . These processes underpin the production of goods (such as seafood and timber), life-support functions (water purifi cation and fl ood control), and life-fulfi lling conditions (beauty and inspiration), as well as the preservation of options (such as genetic diversity for future use). Ecosystems and human health are thus intimately interlinked. The preceding three chapters illustrate how changes in land use and climate can impact health directly, and how numerous indirect impacts on human health are mediated through changes in the composition of species in a given ecosystem. Here, we explore more directly the ways in which the condition of ecosystems and the health of human populations are linked, and we explore prospects for illuminating these linkages to advance scientifi c understanding and inform management options and decisions. The kinds of questions that stand out include,