Data were collected from coastal wetlands (tidal swamps and marsh) along the Waccamaw and Savannah Rivers in South Carolina and Georgia (See Krauss et al. 2009 for additional details). Data collected include water level, porewater salinity (conductivity based), water temperature, and conductivity. First measurements began in 2004 and continued through 2016. Water level data: A network of water level recorders was established in 2004-2006 (forests) and in 2009 (marsh). Continuous hourly data were recorded using vented pressure transducers (model 138, Infinities USA, Port Orange, FL, USA) placed at the bottom of 7.6-cm diameter PVC pipes to an approximate depth of 1 m. All data were collected within the wetland and not in stream. In the data, 0 inches is approximate ground level. Porewater data: Salinity (conductivity based), temperature, and conductivity data were collected monthly from four wells per site. Wells were made of slotted 3.2-cm PVC and inserted into ground to a depth of 0.6 m. Salinity, conductivity, and water temperature were measured with a portable conductivity meter placed inside the well (Model 30, YSI Inc., Yellow Springs, OH, USA). Wells were capped and were pumped of residual water and allowed to refill prior to measurement. Disclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Literature: Krauss, K.W., J.A. Duberstein, T.W. Doyle, W.H. Conner, R.H. Day, L.W. Inabinette, and J.L. Whitbeck. 2009. Site condition, structure, and growth of baldcypress along tidal/non-tidal salinity gradients. Wetlands 29(2):505-519. https://doi.org/10.1672/08-77.1. Cormier, N., K.W. Krauss, W.H. Conner. 2013. Periodicity in stem growth and litterfall in tidal freshwater forested wetlands: Influence of salinity and drought on nitrogen recycling. Estuaries and Coasts 36(3):533-546. https://doi.org/10.1007/s12237-012-9505-z.