A quantitative approach to evaluating ecosystem services

Ecosystem services are benefits that humans receive from their environment. The amount of research that has been done on the concept of ecosystem services has increased substantially in recent years. However, the concept of ecosystem services has been slow to affect actual land management, economic and policy decisions. We argue that one reason for this lack of application is the disparity of methods to quantify ecosystem services. Much of the current ecosystem service research has been done on valuing ecosystem services, with little work done to quantify them so that they can be used as an end point of watershed management. We propose methods to quantify five provisional and regulatory ecosystem services with inputs related to ecosystem functions. We demonstrate the effectiveness of these methods by applying them to a study watershed and then running three extreme land use scenarios for the watershed: all forested, all urban and all corn. Results show that the methods capture the differences in land use on ecosystem service provision. These methods can be a building block for quantification of the full suite of ecosystem services by incorporating more biophysical models and developing validation methods.