It is important to have a single definition of 'ecosystem services', but a single classification scheme for services is not appropriate, according to researchers. There are many contexts in which ecosystem services can be used and the context should help to determine which classification scheme is the most appropriate for decision making.
Human wellbeing depends on the many services provided by ecosystems, such as clean water and food. In developing the concept of ecosystem services, a number of classification schemes have been proposed, such as those in the Millennium Ecosystem Assessment1.
However, the researchers suggest that classification of ecosystem services should be based on: a clear definition of ecosystem services; understanding the characteristics of the ecosystem or ecosystem services being considered; and an understanding of the decision context in which the ecosystem services are being used.
As yet, there has not yet been a consistent definition of ecosystem services, which is needed to allow for meaningful comparisons across different policy contexts and projects. The researchers propose a definition of ecosystem services as 'the aspects of ecosystems utilised (actively or passively) to produce human wellbeing'.
Ecosystem services therefore include the structure or organisation of ecosystems, in addition to their processes and/or functions, if they are used by people. The functions or processes only become services if people benefit from them, such as wetlands providing protection from floods.
Following this definition, key characteristics of the services and the ecosystems can be considered. For example, by understanding that there are seasonal fluctuations in water from streams used for irrigation, we can be better prepared by collecting water or improving irrigation management. However, decisions about using ecosystems services are made in specific social or political contexts. The researchers suggest this context as well as the characteristics of ecosystems should also be taken into account when deciding which classification system to use.
For example, one way to classify ecosystem services would be to use their 'spatial' characteristics. This classification system would be suitable when the decision is based on how to manage the provision of ecosystem services over different scales at a landscape level. One category in this classification system might be 'in-situ', representing the situation where the provision and benefit of the services are located in the same place.
Source: Fisher, B., Kerry Turner, R., Morling, P. (2009). Defining and classifying ecosystem services for decision making. Ecological Economics. 68: 643-653.