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,
periphyton and microbe in the sawgrass-peat ecosystem, summarized
detailed methodology and results (Wilson et al. 2019; Servais et al.
2019; Mazzei et al. in press). 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.