A recent analysis highlights the difference between the academic concept and the practical concept of ecosystem services. It suggests that academic science aims to discover and apply general and timeless concepts to measure ecosystem services, whereas in practice, stakeholders´ valuations of ecosystem services vary with place and time.
The term 'ecosystem service' was first used in the early 1980s to provide a framework for understanding ecosystem processes in terms of their contribution to human well-being. Since then, a growing body of research has discussed how to value ecosystem services so that these services are acknowledged and the ecosystems that provide them are conserved.
The researchers argue that the academic literature about ecosystem services relies on a conceptual basis that differs dramatically from the kinds of information that stakeholders depend on when evaluating ecosystem services. Ecologists and other scientists seek knowledge that is centralised, collaborative, replicable, and based on consensus. In contrast, the information used by stakeholders to set values tends to be dispersed, temporary, local and dependent on existing practices and institutions. The analysis illustrates this difference with three well-known examples of ecosystem services: pollination of citrus and almond trees by bees, pest control by birds and wastewater treatment by wetlands.
The analysis argues that natural ecosystems would not provide the pollinators needed by almond growers in California, who, as a result, import hives of non-native honey bees. These bees often cross-pollinate citrus crops causing them to lose value. The conflict of interest between citrus and almond growers has led to negotiations that do not gain from scientific generalities about the ecosystem service of pollination provided by bees. Ecologists may not consider negative economic impacts when assessing the value of ecosystem services.
The analysis also examines pest control services provided in apple orchards by great tits, who reduce caterpillar damage. Although ecologists would identify this to be a generally valuable service, its value varies depending on region. In orchards that use pesticides there may be no additional value, whereas in organic orchards the value could be significant (although there is relatively little production of organic apples in Europe). In addition, orchardists cannot be sure that the short nesting period of the great tit will occur at the same time as the emergence of the winter moth caterpillar. Again, this illustrates how local market knowledge may have different implications than more general scientific knowledge.
Many researchers in ecological economics have highlighted the value of wetlands in the treatment of wastewater. Citing the example of an American potato chip maker that used a neighbouring wetland to treat its waste, the researchers demonstrate that the wetland provided the service temporarily and the service's value could not be applied to wetlands in general, or even to the same wetland a few years later. The value of the service provided by the wetland continually changed as a result of changing market conditions and was continually adjusted by bargaining between the plant owner and state and local officials.
In conclusion, the study suggests that ecological economists need to ensure they interact with stakeholders and interest groups in order to understand better the 'real' value of ecosystem services. They may apply the concept of ecosystem services more usefully in environmental policy if they worked to narrow the gap between market-based and science-based methods of gathering information and facilitated communication between scientists and stakeholders.