Do restored wetland hydropatterns and sediment accretion rates mimic those in remnant bottomland hardwood wetlands?

Kentucky has lost over 80% of its wetland area since the 1780s, mainly through the conversion of bottomland hardwood wetlands to agriculture. Kentucky’s Wetlands Reserve Program was designed to support the restoration of historical wetlands that have the capacity to be returned to their natural hydrologic regimes, supporting services such as the retention of sediment. The goals of our study were to (1) determine a baseline range of hydropatterns and short-term sedimentation rates in remnant wetlands of western Kentucky, and (2) determine if ~ 10-year-old easements mimic these remnant systems. We collected data at four easements with adjacent bottomland hardwood wetlands, and at two reference standard bottomland hardwood wetlands. Two subsurface wells and 32 sediment traps were placed at each site from October 2020 to October 2021. All sites maintained water levels within the top 30 cm during the growing season, indicative of wetland hydrology. Hydropatterns in reference standard and remnant sites were highly variable; some sites followed expected trends, drying in the summer with increased evapotranspiration, while others maintained high water associated with the presence of beavers. Easements generally fell within this range of hydropatterns, but three of the easements differed from their paired remnant sites in terms of their intensity and/or duration of flooding events. There was also high variation in the sedimentation accretion rates, both between and within sites; sediment depths ranged from 0 to 8 cm. A quantification of sediment accretion rates is forthcoming