The Conservation Effects Assessment Project (CEAP) is a multi-agency effort to evaluate the effectiveness of conservation practices used by private landowners participating in selected U.S. Department of Agriculture (USDA) conservation programs. One component of CEAP seeks to value wetlands restoration effected by the Wetland Reserve Program (WRP) in the Lower Mississippi Alluvial Valley (LMAV) by quantifying and monetizing ecosystem services. Focusing on hardwood bottomland forest, a dominant wetland type of the LMAV, in situ measurements of multiple ecosystem services were made on a land use continuum of agricultural land, wetlands restored via WRP, and mature bottomland forest. A subset of these services, namely greenhouse gas (GHG) mitigation, nutrient mitigation, and waterfowl recreation, were selected to be monetized with benefit transfer methods. Above- and belowground carbon estimates are utilized to project GHG flows on the land. Denitrification potential and foregone fertilizer application are summed to estimate the amount of mitigated nitrate. Increased duck energy days (DEDs) on the landscape represent the WRP-induced expansion of waterfowl habitat. We adjust and transform these measures into per hectare, valuation-ready units and then monetize with prices from emerging markets (GHG) and environmental economic literature (GHG, nutrient, recreation).
Results/Conclusions
Valuing all services produced by wetland restoration would yield the total ecosystem value, whereas we generate a partial estimate by monetizing three ecosystem services. Social welfare value is found to be between $287 and $394 per hectare per year, with GHG mitigation valued at $57 to $74, nitrate mitigation $180 to $220, and waterfowl recreation $50 to $100 per hectare. Limited to existing markets, annual private value is merely $25-40 per hectare, composed of $15 for GHG mitigation and $10 to $25 per hectare for waterfowl recreation. When fully accounting for potential markets, annual private value rises to the range of $367 to $457 per hectare as GHG mitigation is $137, nitrate mitigation $180 to $220, and waterfowl recreation $50 to $100 per hectare. Aggregating over all WRP hectares in the LMAV study area, annual value of selected ecosystem services is over $20 million, while it is about $575 million when considering all hectares potentially restorable to wetlands. The findings that annual social value and potential private value are greater than regional agricultural rents ($150-200 per hectare) motivate the development of ecosystem markets to more fully integrate societal values into land use decisions.