Potential effects of climate change on NRCS Wetland Restoration Easements: An ecohydrological assessment

摘要

Water cycles are expected to change globally with predicted climate warming. Yet predicted shifts in hydrological regimes are rarely incorporated into wetland restoration planning, despite large investments in projects very susceptible to hydrological changes. We assessed potential effects of climate change on previously restored wetlands to identify siting and design issues for use in guiding adaptive management or planning future restoration projects. Five United States Department of Agriculture Natural Resources Conservation Service Wetland Reserve Easements in Genesee County, New York, were studied from 2013 through 2014. Elevations of surface water and groundwater were monitored, piezometric measurements made, and water chemistry and plant community data collected. Precipitation, surface water, and groundwater hydrologic data were used to relate each restored wetland to vulnerability of climate change. Although all five sites were functioning as planned, three sites had less vulnerability to climate change due to their connection to more stable sources of groundwater, position within the hydrological landscape, or design features that mimic the natural landscape. Suggestions for adaptive management on already implemented projects include actively managing water-control structures, enhancing microtopography, and increasing plant diversity by planting or seeding. Potential sites for future restoration projects should be ranked based on location in the watershed, presence of hydric soils, past and potential hydrological connections, and sustainability of hydrology, especially groundwater sourcing. Design options should attempt to mimic natural landscape features, refrain from overengineering, and allow for flexible management of hydroperiods.