In the first chapter we encountered the concept of wetlands providing services such as food production and climate regulation. How much are they worth? One estimate is $14,785/ha per year for interior wetlands and $22,832/ha per year for coastal estuaries (Costanza et al.1997). That is, a hectare of wetland produces services that are roughly the value of a small car or a year of university tuition, each year. Another estimate gives the global value of $1.8 billion per year (Schuyt and Brander 2004). Where do such numbers come from? In this chapter we shall look at some examples of services provided by wetlands, focusing on three areas: production of food, regulation of the atmosphere, and culture/recreation. Efforts to quantify these services are not without their critics. There are those who resist putting dollar values on nature, since not everything that humans value has a price. None the less, the use of human currency to evaluate natural services is a growing field in economics (e.g. Costanza et al. 1997). Even if you have reservations about the approach, you need to understand how it is done.

Wetlands have high production

The capture of solar energy by plants is the foundation of virtually all life on Earth. The enormous production of human food in wetlands including rice, fish, amphibians, crustaceans, and mammals testifies to the rate of production in wetlands. The rate of organic production in wetlands is one of the highest in the world, matched nearly by tropical forest.