Ecosystem services represent all the things that functioning ecosystems do for people that people generally do not have to pay for. Examples include a forested hillside filtering water and retaining topsoil/sediments, how trees remove carbon from the atmosphere, or how a mangrove buffers surrounding low-lying lands from wave action and storm surge. When ecosystem services are lost, the human-made substitutes (such as a water filtration plant, erosion retaining walls, etc.) are often costly, and costly to maintain. Environmental management decisions are increasingly incorporating estimates of ecosystem service values as part of the cost–benefit evaluations. The intent of many ecosystem service efforts are to internalise ecosystem contributions into decision-making, thus stemming ecosystem service loss. However, accomplishing this requires not only stemming the loss of ecosystem services, but also addressing the increasing human demands for them.

Key Concepts:

• Ecosystem services are those processes of ecosystems that support (directly or indirectly) human well-being.
  
• The concept of ecosystem services is of interest to economists, ecologists and many other disciplines for its ability to create cross-discipline dialog.
  
• Ecosystem services provide valuable social benefits, which are often not accounted in standard economic currencies. Left unaccounted, they are vulnerable to loss. Numerous tools are emerging to visualise this value, supporting protection and/or restoration of ecosystem services.
  
• Much of the current focus on ecosystem service work bases its emphasis on the supply of ecosystem services. For this concept to support sustainability objectives however, growing demands for ecosystem services must be addressed through changes in behaviour, technology, governance and design.