Continuous monitoring data from natural and restored salt marshes on Cape Cod, Massachusetts, 2016-17

Continuous monitoring data reported are a portion of data from a larger study investigating changes in soil properties, carbon accumulation, and greenhouse gas fluxes in four recently restored salt marsh sites and nearby natural salt marshes. For several decades, local towns, conservation groups, and government organizations have worked to identify, replace, repair, and enlarge culverts to restore tidal flow upstream from historical tidal restrictions in an effort to restore salt marsh ecosystems on Cape Cod, Massachusetts. Undersized or failed culverts restrict tidal exchange between the marsh and the bays and estuaries, which leads to alterations in plant community composition and in fundamental processes controlling soil carbon accumulation, soil carbon transformations, and greenhouse gas emissions. In this study, sites were selected to compare salt marshes restored over a range of years and to compare marshes upstream and downstream from a restored tidal restriction. Salt marshes downstream from tidal restrictions represent "natural" conditions because hydrology was not substantially altered, whereas marshes upstream from repaired culverts represent "restored" conditions. At each of the four salt marsh sites, study plots were established on the natural and restored sides of the former tidal restriction. Well water-level loggers, soil and air temperature loggers, and photosynthetically active radiation (PAR) sensors were deployed over the growing season to coincide with discrete measurements of greenhouse gas fluxes made by study collaborators. Water-level loggers were also deployed in creeks near the restored tidal restriction.