The Salinity and phosphorus mesocosm experiment in freshwater sawgrass wetlands: Determining the trajectory and capacity of freshwater wetland ecosystems to recover carbon losses from saltwater intrusion (FCE LTER), Florida, USA from 2015 to 2018

In experimental wetland mesocosms located at Florida Bay Interagency
Science Center, Key Largo, Florida, researchers continuously added
salinity (approximately 6.9 g salt d-1) and phosphorus ( approximately
0.5 mg P d-1) to Cladium jamaicense peat monoliths from February 2015
to February 2017 and quantified changes in carbon partitioning.
Several studies, focusing on the functional roles of marsh, soil, and
microbe in the sawgrass-peat ecosystem, summarized detailed
methodology and results (Wilson et al. 2019; Servais et al. 2019).
Briefly, salinity was increased (~10 ppt) and phosphorus was added
(0.45 mg P d-1) to simulate four treatment effects (n = 24 plots): i)
freshwater and no-added phosphorus, ii) freshwater and added
phosphorus, iii) saltwater and no-added phosphorus, and iv) saltwater
and added phosphorus. Upon the termination of manipulation study
(early February 2017), containers holding water and peat-sawgrass
cores were drained, rinsed, and refilled with only freshwater without
any added nutrient and salt. Then, we experimentally restored
freshwater to previous treatment and control mesocosms from February
2017 to June 2018 to examine the capacity of wetland ecosystems to
recover carbon losses from saltwater intrusion. Note that
FCE1226_Water_quality.csv summarizes water quality during both the
manipulation and restoration study; however, all other files in the
Dataset Title section only summarize results from the restoration
study. Detailed methodology is provided below.