Today, ecosystem services ESS are described by different scholars using different definitions, leading to divergent conclusions. Ecologists start with the (nested) ecological systems, analyse their structures and elements,... [ view full abstract ]
Today, ecosystem services ESS are described by different scholars using different definitions, leading to divergent conclusions.
- Ecologists start with the (nested) ecological systems, analyse their structures and elements, model and measure functions of the system (not functions for anybody), and draw conclusions. The results are usually replicable and to a large degree independent of subjective preferences.
- ESS researchers tend start from the services, a social science approach starting with benefits to people. Service, service potential ESP and ecosystem function ESF are taken to be identical, ESS := ESP := ESF, differing only by a (never specified or defined) load factor.
- Economists extend the chain, starting with ecosystem service benefits ESB and equating them with the services as defined by ESS researchers. In this perception, ESB := ESS := ESP := ESF, again unambiguously.
Instead we suggest describing the “cascade” ESF -> ESP -> ESS -> ESB not as a natural trickle-down but as a managed process, taking the natural science position as a starting point. From there on it is necessary to make the human agency explicit, as each further step is shaped by social processes as much as by natural ones.
The definition of ESPs is the point where the subjective choices and social processes come in: different systems and their ESF are attributed different ESPs, not in an unambiguous way, but as a result of societal and political processes including conflicts of interest and manifestations of power relations. The ESP finally acknowledged and exploited is usually one of many ESPs provided by the ecosystem. Sociology and political science are crucial to understand these processes. As a result, functions, potentials and services can no longer be treated as identical: ESF ≠ ESP ≠ ESS => ESB.
Rethinking ESS should start with a new definition acknowledging the subjectivity of choice, for instance the one suggested by Harrington et al. (2009) “Ecosystem Services are the benefits humans recognise as obtained from an ecosystem and that support, directly or indirectly, their survival and quality of life”. This should appeal to economists who always work based on subjective preferences which in turn can only form if the relevance (positive or negative) of an object has been recognised. However, for a comprehensive description it should be kept in mind that ESS provision usually occurs in co-production with human labour or at least human activities, including the need to invest resources (in different currencies like energy, material, time, creativity, money), and that the ecosystem disservices EDS should be analysed alongside the services.
Humans value ESB using different value system simultaneously, with no common denominator, and no aggregation possible - an issue of psychology. The “total value of ecosystems and their services” as an aggregate, perceived as such by citizens, simply does not exist. What is valued changes over time: 20 years ago carbon sequestration was not mentioned as a service, and what will be valued in future is unknown (is the thermo-haline circulation an ESS?). New ESS can be defined out of thin air, if derived from a proven ESF. Thus claiming to calculate the total value of the Earth’s ESS is nonsensical.
Key words: Ecosystem services, terminology, valuation, aggregation, disciplinary entry points
3c. Ecosystem services (definition, measurement, multi-criteria valuation)
