Mapping ecosystem services: Practical challenges and opportunities in linking GIS and value transfer

In this paper, a decision framework designed for spatially explicit value transfer was used to estimate ecosystem service flow values and to map results for three case studies representing a diversity of spatial scales and locations: 1) Massachusetts; 2) Maury Island, Washington; and 3) three counties in California. In each case, a unique typology of land cover and aquatic resources was developed and relevant economic valuation studies were queried in order to assign estimates of ecosystem service values to each category in the typology. The result was a set of unique standardized ecosystem service value coefficients broken down by land cover class and service type for each case study. GIS analysis was then used to map the spatial distribution of each cover class at each study site. Economic values were summarized and mapped by tributary basin for Massachusetts and California and by property parcel for Maury Island. For Maury Island, changes in ecosystem service value flows were estimated under two alternative development scenarios. Drawing on lessons learned during the implementation of the case studies, the authors present some of the practical challenges that accompany spatially explicit ecosystem service value transfer. They also discuss how variability in the site characteristics and data availability for each project limits the ability to generalize a single comprehensive methodology.