Healthy ecosystems provide human communities with a variety of services and goods including the provision of food, clean water, fuel, and natural medicines. They also help to regulate disease, provide protection against natural disasters, improve air quality, and support agriculture through pollination and soil formation (Dobson et al. 2006). The Millennium Ecosystem Assessment (MA), led by the United Nations, mapped out the nature and extent of human reliance on ecosystem services and found that the growing demand for natural resources over the last 50 years has resulted in the degradation or unsustainable use of 60% of the ecosystem services that were assessed. Furthermore, the MA projected that the decline in ecosystem services will worsen over the first half of this century and is a significant barrier to achieving the Millennium Development Goals (MDGs) (MA 2005a).
The decline in ecosystem services disproportionately impacts the world’s poorest populations; more than a billion people worldwide live on about one US dollar per day and many of them are directly dependent on these services to meet basic needs (The World Bank 2012, UNEP 2012a). The rural poor, many of whom live in areas that have already experienced widespread ecosystem degradation, are particularly vulnerable to the loss of ecosystem services. It seems unlikely that the MDGs of improving health and decreasing hunger and poverty among these populations can be addressed effectively or sustainably in the face of ongoing biodiversity loss and ecosystem degradation (MA 2005a).
The economic and social value of ecosystem services is often underestimated or not accounted for at all in many policy and economic decisions (Holzman 2012). In part, this is due to gaps in understanding of the full range and benefits of ecosystem services. However, as research on the valuation of ecosystem services has progressed over the last two decades, some governments and other institutions have initiated programs that provide economic incentives for the preservation of these services (UNEP 2012a). Payment for ecosystem services (PES) programs have been instituted in a variety of settings since the mid 1990’s; for example, the Chinese government implemented a program in response to devastating floods in 1999 that compensated farmers with money or grain in exchange for restoring forests in critical watershed regions (Tallis et al. 2008).
While PES programs have been successful in preventing further ecosystem degradation in some settings, many important policy and economic decisions at local, regional, and international levels continue to be made without fully taking into account the wide range and full value of ecosystem services. For example, economic development programs that subsidized the clearing of mangrove forests in Asia for shrimp aquaculture have deprived many communities of the important ecosystem services provided by intact mangrove forests, including protection from natural disasters and water filtration (Tallis et al. 2008). The loss of these ecosystem services was particularly evident during the 2004 Asian tsunami when communities with intact mangrove forests suffered far less damage than those with degraded forests (Danielsen et al. 2005).
Supporting services, including photosynthesis, soil formation, and nutrient cycling, ensure the production of all other ecosystem services (MA 2005a).Read more
Provisioning services refer to the products that are derived directly from ecosystems, including plant and animal species for food, wood for fuel, and natural medicines (Melillo and Sala 2008).Read more
Regulating services are benefits that are derived through the regulation of ecosystem processes, including air and water purification and climate regulation (MA 2005a).Read more
Cultural services refer to the nonmaterial benefits derived from ecosystems, including recreation, aesthetic appreciation, and a “sense of place” for communities (Daniel et al. 2012).Read more