ABSTRACT
In 2005 the Millennium Ecosystem Assessment (MA) defined a framework for relating ecosystem services to the larger scientific and policy communities. It proved to be an important development and excellent heuristic. The MA divided ecosystem services into a few very understandable categories – supporting services, regulating services, provisioning services and cultural services. This in turn makes the classification scheme readily accessible as a heuristic to decisionmakers and non-scientists. The MA delivered a broad definition (by design) of ecosystem services as ‘the benefits humans obtain from ecosystems’. However, this definition has not been shown to be operational for all research purposes (Boyd and Banzhaf, 2007; Wallace, 2007; Fisher and Turner, 2008; Maeler et al., 2008), and efforts have been made to more carefully classify and understand ecosystem services to make their analysis more operational (see Fisher et al., 2009 for review). We have argued elsewhere (Fisher and Turner, 2008; Fisher et al., 2009) that a simpler delineation of intermediate services, final services and benefits is more useful for valuation. There are multiple relationships between ecosystem processes and human benefits (see Boyd and Banzhaf, 2007 for a description of the benefit-dependence aspect of ecosystem services), but what is important for valuation exercises is that you value the endpoints that have a direct effect on human welfare – in economics these are considered through the use of the term ‘benefits’. Both intermediate and final services are ecological phenomena (as opposed to things like cultural fulfilment). The term ‘intermediate services’ here is similar to the MA’s ‘supporting services’, and these intermediate services combine in complex ways to provide final services, which have direct effects on human welfare. Benefits, which include things like wood, food and cultural aspects and recreation, are related but different to the services that provide them. For example, water regulation and drinking water are not the same thing. Benefits also typically require other forms of capital to affect human welfare. For example, clean drinking water for consumption is a benefit of the final service of water provision. In turn, water provision by an ecosystem is a function of the intermediate services, including nutrient cycling and soil retention. The end benefit typically requires some built capital to be realized, whether it is a well or an urban water distribution system. In this scheme we avoid the double counting flaws acknowledged in earlier ecosystem service valuation exercises. This is not the case for the MA classification, which could lead to double counting the value of some ecosystem services. For example, in the MA, nutrient cycling is a supporting service, water flow regulation is a regulating service, and recreation is a cultural service. However, if you were a decision-maker contemplating the conversion of a wetland, and you utilized a cost-benefit analysis including these three services, you would commit the error of double counting. This is because nutrient cycling and water regulation both help to provide the same service under consideration, providing usable water. The MA’s recreation service is actually a human benefit of that water pro-
vision. An analogy is that when buying a live chicken you do not pay for the price of a full chicken, plus the price of two legs, two wings, head, neck and other body parts, you simply pay the price of a whole chicken. Figure 2.1 provides a conceptual example of our schema, where complex ecosystem processes and functions give rise to ecosystem services (final and intermediate), which then interface with direct human usage and provide benefits. Again, some benefits require other forms of capital in order to be realized. For example, hydroelectric power requires water provision and regulation from ecosystems, but also requires dams and transmission infrastructure. This line of argument, however, is not meant to imply that intermediate services have no value. Without a sufficient configuration of structure and processes, ecosystems will not function (or will function less well) and will not provide the diverse range of final services and benefits that they could potentially deliver (Turner, 1999; Gren et al., 1994). Regulating services that provide the capacity to respond to environmental stresses and shocks are encompassed by the concepts of infrastructure or primary value associated with the role that functional diversity can play in certain contexts, providing increased ecological stability and resilience. The conservation and protection of regulating and support
services capacity is in some ways a decision about reducing risk and the costs of such a risk averse strategy.
