Putting a value on freshwater ecosystems

Posted on January 5, 2013

Ecosystem services provided by inland water bodies can be classified as provisioning services (e.g. fodder for livestock), regulating services (e.g., soil formation and fertility; water purification; food and habitat for wild animals), or cultural services (e.g., recreation; aesthetics).  Studies of ecosystem services have generally been carried out either by ecologists interested in the biological processes responsible for particular services, or by economists interested in giving services a monetary value.  In a study of the Donana wetlands, a social-ecological system in southern Spain, researchers attempted to link these approaches by exploring links between ecological function and the value of services to different stakeholders.  Using multivariate pattern analyses, data on 144 aquatic plant species were used to define seven functional groups on the basis of traits such as plant growth form, height, life span and flower attractiveness, which were linked in turn to various ecosystem properties and services.  In another part of the study, 477 stakeholders were interviewed and classified according to their perceptions of aquatic ecosystem services, their relationships to the study area, and sociodemographic factors.  The information provided by stakeholders included the amount of money they would be prepared to pay for a given ecosystem service.  There were clear links between different stakeholder groups and the types of services that were valued – for example, direct uses such as provisioning and cultural services were especially valuable to  local stakeholders and nature tourists, while indirect regulating services were most valued by environmental and other professionals.  However, there was a mismatch between functional groups and perceived economic value, with stakeholders tending to ignore ecosystem function when assigning values to different services, even when provided with thorough information on such functions.  These findings highlight the limitations of conventional contingent valuation techniques which treat respondents as economic consumers rather than as citizens with broader concerns, and suggest that non-monetary measures such as quality of life might be more appropriate when evaluating ecosystem services.

Reference:  Garcia-Llorente, M., Martin-Lopez, B., Diaz, S. & Montes, C.  2011.  Can ecosystem properties be fully translated into service values?  An economic valuation of aquatic plant services.  Ecological Applications 21(8) 3083–3103.   http://www.esajournals.org/doi/pdf/10.1890/10-1744.1