Meta-analysis for the transfer of economic benefits of ecosystem services provided by wetlands within two watersheds in Quebec, Canada

Climate change will cause major changes in ecosystems. Therefore, it is crucial that climate change policy consider the value of all services that are provided by watershed ecosystems. For this purpose, geospatial data and economic analysis are combined to determine a monetary value for wetland ecosystem goods and services (EGSs) in the watersheds of the Yamaska and Bécancour Rivers (Quebec, Canada). From published studies of wetland economic evaluations, we selected 51 relevant studies from 21 countries and performed a benefit transfer using meta-analysis. Our research emphasises the importance of considering multiple wetland characteristics when conducting a benefit transfer because of their complementary effects. We propose an approach that integrates spatial variables that have not been previously used, including type of wetland (complex or isolated) and land use (% of agricultural, urban, forest and water land cover), at a much finer geographical scale of 50 km2. Simultaneous use of detailed spatial and economic characteristics in each wetland area allowed us to assign heterogeneous EGS values and map these values in sub-watersheds (50 km2) of the two rivers. Our results demonstrate that location and scale can affect wetland value. When wetland valuation was conducted based on mean values for geospatial characteristics, the EGS [2014 purchasing power parity (PPP) price] that is provided by wetlands was $5277 PPP/ha/year for the Yamaska River Watershed (YRW) and $3979 PPP/ha/year for the Bécancour River Watershed (BRW). When wetland valuation was performed at a more detailed sub-watershed scale to reflect variability within a watershed, EGS (2014 PPP price) that is provided by wetlands was valued higher at $9080/ha/year for YRW and $4702/ha/year (2014 PPP price) for BRW.