Dataset title: Nutrient data from the Peat Collapse-Saltwater Intrusion Field Experiment from brackish and freshwater sites within Everglades National Park, Florida (FCE LTER), collected from October 2014 to September 2016 Dataset ID: FCE1220 Research type: Short-term Dataset Creator Name: Dr. Benjamin Wilson Position: Project Collaborator Organization: Southeast Environmental Research Center Address: Florida International University University Park OE 148 Miami, FL 33199 USA Phone: 305-348-1453 Fax: 305-348-4096 Email: bwils034@fiu.edu URL: http://wetland.fiu.edu/ Name: Dr. Tiffany Troxler Position: Project Collaborator Organization: Southeast Environmental Research Center Address: Florida International University University Park OE 148 Miami, FL 33199 USA Phone: 305-348-1453 Fax: 305-348-4096 Email: troxlert@fiu.edu URL: http://wetland.fiu.edu/ Metadata Provider Organization: Florida Coastal Everglades LTER Program Address: Florida International University University Park OE 148 Miami, FL 33199 USA Phone: 305-348-6054 Email: fcelter@fiu.edu URL: http://fcelter.fiu.edu Dataset Abstract With sea level rise increasing, saltwater intrusion into low-lying coastal wetlands is likely to occur.  We simulated saltwater intrusion into an Everglades marsh through monthly additions of elevated salinity water. Monthly porewater nutrients were taken at 15 cm depth from a brackish and a freshwater marsh. Porewater physicochemistry was measured 24 hours after dosing. Collection occurred from Oct 2014 - Sep 2016. The collected water was then analyzed for temperature, conductivity, salinity, pH, alkalinity, chloride, DOC, NH4, SO4, TDN, SRP, TDP, and sulfide. These data are published in Wilson, B.J., Servais, S., Mazzei, V., Davis, S.E., Kelly, S., Gaiser, E., Kominoski, J.S., Richards, J., Rudnick, D., Sklar, F., Stachelek, J., and Troxler, T.G. Salinity pulses interact with seasonal dry-down to increase ecosystem carbon loss in marshes of the Florida Everglades. 2018. Ecological Applications 28:2092-2018. Geographic Coverage Study Extent Description Bounding Coordinates Geographic description: Coordinates indicate the center of our plots at a brackish water marsh within Everglades National Park West bounding coordinate: -80.84 East bounding coordinate: -80.84 North bounding coordinate: 25.22 South bounding coordinate: 25.22 Geographic description: Florida Coastal Everglades LTER Study Area: South Florida, Everglades National Park, and Florida Bay West bounding coordinate: -81.078 East bounding coordinate: -80.490 North bounding coordinate: 25.761 South bounding coordinate: 24.913 Temporal Coverage Start Date: 2014-10-01 End Date: 2016-10-01 Data Table Entity Name: FCE1220_BW_FW_Nutrients.txt Entity Description: Nutrient dataset for Ben Wilson's Salt Water Intrusion/Peat Collapse study Object Name: FCE1220_BW_FW_Nutrients.txt Data Format Number of Header Lines: 1 Attribute Orientation: column Field Delimiter: , Number of Records: Attributes Attribute Name: site Attribute Label: Site Attribute Definition: Collection site Storage Type: code Measurement Scale: BW = brackish water Missing Value Code: Attribute Name: plot Attribute Label: plot Attribute Definition: plot number Storage Type: Text Measurement Scale: plot number Missing Value Code: Attribute Name: date Attribute Label: date Attribute Definition: date Storage Type: datetime Measurement Scale: Missing Value Code: Attribute Name: treatment Attribute Label: treatment Attribute Definition: treatment label Storage Type: code Measurement Scale: control = Ambient water added treatment = saltwater added Missing Value Code: Attribute Name: temp Attribute Label: temperature Attribute Definition: temperature Storage Type: data Measurement Scale: Units: celsius Number Type: real Missing Value Code: NA (Not available) Attribute Name: cond Attribute Label: conductivity Attribute Definition: conductivity Storage Type: data Measurement Scale: Units: microSiemensPerCentimeter Number Type: real Missing Value Code: NA (Not available) Attribute Name: salinity Attribute Label: salinity Attribute Definition: salinity Storage Type: data Measurement Scale: Units: partsPerThousand Number Type: real Missing Value Code: NA (Not available) Attribute Name: ALKA Attribute Label: Alkalinity Attribute Definition: Alkalinity Storage Type: data Measurement Scale: Units: milligramsPerLiter Number Type: real Missing Value Code: NA (Not available) Attribute Name: CL Attribute Label: Chloride Attribute Definition: Chloride Concentration Storage Type: data Measurement Scale: Units: milligramsPerLiter Number Type: real Missing Value Code: NA (Not available) Attribute Name: DOC Attribute Label: Dissolved organic carbon Attribute Definition: Dissolved organic carbon Concentration Storage Type: data Measurement Scale: Units: milligramsPerLiter Number Type: real Missing Value Code: NA (Not available) Attribute Name: pH Attribute Label: pH Attribute Definition: acidity of basicity Storage Type: data Measurement Scale: Units: dimensionless Number Type: real Missing Value Code: NA (Not available) Attribute Name: NH4 Attribute Label: ammonium Attribute Definition: ammonium concentration Storage Type: data Measurement Scale: Units: milligramsPerLiter Number Type: real Missing Value Code: NA (Not available) Attribute Name: SO4 Attribute Label: sulfate Attribute Definition: sulfate concentration Storage Type: data Measurement Scale: Units: milligramsPerLiter Number Type: real Missing Value Code: NA (Not available) Attribute Name: TDN Attribute Label: total dissolved nitrogen Attribute Definition: total dissolved nitrogen concentration Storage Type: data Measurement Scale: Units: milligramsPerLiter Number Type: real Missing Value Code: NA (Not available) Attribute Name: SRP Attribute Label: soluable reactive phosphorus Attribute Definition: soluable reactive phosphorus concentration Storage Type: data Measurement Scale: Units: microMolesPerLiter Number Type: real Missing Value Code: NA (Not available) Attribute Name: TDP Attribute Label: total dissolved phosphorous Attribute Definition: total dissolved phosphorous concentration Storage Type: data Measurement Scale: Units: microMolesPerLiter Number Type: real Missing Value Code: NA (Not available) Attribute Name: sulfide Attribute Label: sulfide Attribute Definition: sulfide concentration Storage Type: data Measurement Scale: Units: milliMolesPerLiter Number Type: real Missing Value Code: NA (Not available) Methods Sampling Description Method Step Description This study was conducted in Everglades National Park, Florida, USA along the southeastern boundary of Shark River Slough, the largest drainage basin in the southern Everglades. The coastal Everglades range along a gradient from freshwater sawgrass ridges and sloughs to coastal mangrove forests. We chose two sites for our study: a brackish marsh that was already experiencing saltwater intrusion and a freshwater marsh that, to our knowledge, had not experienced elevated salinity. The brackish marsh (25°13’13.17” N, 80°50’36.96” W) was dominated by Cladium jamaicense (sawgrass) sparsely interspersed with Conocarpus erectus (buttonwood). The site was non-tidal and characterized by distinct wet-dry hydrologic regimes in which the site was flooded for ~8 months out of the year (mean since 2000, Everglades Depth Estimation Network (EDEN) at station NMP). The freshwater marsh (25°26’07.77” N, 80°46’51.50” W) was co-dominated by sawgrass and Eleocharis cellulosa (spikerush) but also contained other freshwater marsh plants such as Crinum americanum (swamp lily), Bacopa caroliniana (waterhyssop), and Panicum hemitomon (maidencane). The hydrologic regime at the site was characterized as long-hydroperi od, flooded nearly year-round (~11 months, mean since 2000, EDEN at station NP62) during a typical season. The soil properties of each site are given in Table 1. Instrumentation Surface water temperature and salinity were measured immediately in the field (YSI). Soluble reactive phosphorus (SRP) and total dissolved P (TDP) were analyzed at the South Florida Water Management District Analytical Research Laboratory on an Alpkem Flow Solution Analyzer (OI Analytical, College Station, TX, USA) following Standard Method 4500-P F (SRP) and Solorzano and Sharp (1980, TDP). Ammonium (NH4+), and dissolved inorganic N (DIN) were analyzed at the South Florida Water Management District Water Quality Laboratory on a Lachat Flow Injection Analyzer (Lachat Instruments, Loveland, CO, USA) following Standard Method 4500-NH3 H (NH4+) or Standard Method 4500-N C (DIN). Dissolved organic C (DOC) was analyzed using a Shimadzu TOC-L analyzer (Shimadzu Scientific Instruments, Columbia, MD, USA) following Standard Method 5310 B. Alkalinity and pH were determined using an automated titrator (Metrohm 855 Titrator, Herisau, Switzerland) following Standard Method 2320 B (Alkalinity) and a modification to Standard Method 4500 H+ B (pH). Chloride (Cl-) and sulfate (SO42-) were measured using a Metrohm 881 Compact IC Pro System (Metrohm, Riverview, FL, USA) following Standard Method 4110 B. Sulfide (HS-) was measured using standard methods (McKee et al. 1988). Method Step Description In September 2014, 16 plots were established at each site along an 80-m long constructed boardwalk (Fig. 1). In twelve plots, we installed 1.4-m diameter, 0.4-m tall clear, cylindrical, polycarbonate chambers by inserting them 30-cm into the soil. We designated 4 additional plots as “no-chamber” controls, and these had no chamber installed around them. Each chamber had a movable collar with a series of 10-cm diameter holes that could be closed during application of dosing water but were open to natural flow at all other times. Six ambient-water addition (“+AMB”) plots were established upstream in the natural flow, while 6 treatment (+saltwater, “+SALT”) plots were established downstream to avoid salt contamination into the +AMB and “no-chamber” control plots. The 4 “no-chamber” controls, which were interspersed within the +AMB plots (Fig. 1), did not receive any water additions and were used only for C flux and redox potential measurements (see below). A 3-m “buffer zone” was established to avoid contamination between salt-dosing and control plots. Method Step Description Experimental water additions began in October 2014 and were conducted monthly for 2 years (see Stachelek et al. (2018) for detailed methods). The volume and salinity of brine solution mixed to deliver our dose varied for each dosing month in order to reach porewater concentration targets. The volume and salinity of the brine solution was calculated based on both water height from soil surface and surface water salinity so that we could reach the target of twice ambient porewater salinity, 2-5 ppt at the FW site and 20 ppt at the BW site. Our brine solution during dosing ranged from 30.7-65.0 ppt at the FW site and 26.8-68.0 ppt at the BW site (Stachelek et al. 2018). The dosing solution was prepared using source water obtained at each study site (when the marsh was wet) or from a nearby canal (when the marsh was dry) with similar nutrient concentrations found in freshwater wetlands of the Everglades (C-111; 25°17'31.74" N, 80°27'21.59" W; Wilson et al. in review); source water was combined with a commercially available sea salt mix (Instant Ocean ® (Atkinson and Bingman 1997)). An equal volume of site surface water or canal water was added to the +AMB plots each month to account for the addition of water in the absence of salinity. Method Step Description The movable collar on the chambers was used to close the chambers while dosing to ensure that the dosing water remained within the chamber. Doses were delivered from elevated boardwalks running alongside each chamber using a submersible bilge-style pump (Xylem Inc, USA). The outlet hose was fitted with a spreader device that split the large output stream into six smaller streams. This design was intended to maximize mixing with ambient site water while minimizing disturbance to sensitive benthic periphyton. Emergent plants were briefly sprayed with freshwater following dosing to avoid potential damage from direct salt application. Chambers remained closed for 24 hours to allow the elevated-salinity water to penetrate into the porewater, then chambers were opened to prevent closure artifacts. Method Step Description Porewater salinity and nutrient measurements were made from three sampling wells (“sippers”) placed randomly inside each chamber to a depth of 15-cm. Porewater salinity was measured 24 and 120 hours after dosing. Two sippers were installed 0.5-m outside the edge of each chamber to monitor any potential leakage of saltwater outside of the treatment plots. Samples for nutrient and carbon analyses were collected 24 h after dosing. From each sipper, a ~25-mL sample was extracted after purging the length of tubing, and temperature and salinity were measured immediately in the field (YSI Model 600 XL, Yellow Springs, OH). The porewater from each of the three wells was then combined into one sample per chamber (~75mL total), field-filtered (0.7 mm GF/F), transferred to new, single-use bottles, stored at 20°C, and analyzed within 21 d. Method Step Description Surface water salinity was collected from each plot during wet periods by collecting 140-mL of sample water and processing the same as porewater. Surface water temperature and salinity were measured immediately in the field (YSI). Soluble reactive phosphorus (SRP) and total dissolved P (TDP) were analyzed at the South Florida Water Management District Analytical Research Laboratory on an Alpkem Flow Solution Analyzer (OI Analytical, College Station, TX, USA) following Standard Method 4500-P F (SRP) and Solorzano and Sharp (1980, TDP). Ammonium (NH4+), and dissolved inorganic N (DIN) were analyzed at the South Florida Water Management District Water Quality Laboratory on a Lachat Flow Injection Analyzer (Lachat Instruments, Loveland, CO, USA) following Standard Method 4500-NH3 H (NH4+) or Standard Method 4500-N C (DIN). Dissolved organic C (DOC) was analyzed using a Shimadzu TOC-L analyzer (Shimadzu Scientific Instruments, Columbia, MD, USA) following Standard Method 5310 B. Alkalinity and pH were determined using an automated titrator (Metrohm 855 Titrator, Herisau, Switzerland) following Standard Method 2320 B (Alkalinity) and a modification to Standard Method 4500 H+ B (pH). Chloride (Cl-) and sulfate (SO42-) were measured using a Metrohm 881 Compact IC Pro System (Metrohm, Riverview, FL, USA) following Standard Method 4110 B. Sulfide (HS-) was measured using standard methods (McKee et al. 1988). Soil redox potential was measured using standard techniques (Faulkner et al. 1989); briefly, three platinum-tipped probes were inserted to 15-cm depth in each plot and allowed to equilibrate for 30 minutes before measurement. Soil bulk density was determined at the end of the experiment by taking one 2.4-cm diameter core per chamber down to 30-cm. Samples were dried at 60°C and weighed to calculate dry bulk density (g cm-3). Quality Control Data are QA/QC'ed by visually plotting data and removing any data points that are plus or minus two standard deviations away from the average Distribution Online distribution: http://fcelter.fiu.edu/perl/public_data_download.pl?datasetid=FCE1220_BW_FW_Nutrients.txt Intellectual Rights This information is released under the Creative Commons license - Attribution - CC BY (https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) is required to cite it appropriately in any publication that results from its use. The Data User should realize that these data may be actively used by others for ongoing research and that coordination may be necessary to prevent duplicate publication. The Data User is urged to contact the authors of these data if any questions about methodology or results occur. Where appropriate, the Data User is encouraged to consider collaboration or co-authorship with the authors. The Data User should realize that misinterpretation of data may occur if used out of context of the original study. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. Thank you. Publications citing this dataset Wilson, Benjamin J., Shelby Servais, Viviana Mazzei, John S. Kominoski, Minjie Hu, Stephen E. Davis, Evelyn Gaiser, Fred Sklar, Laura Bauman, Stephen Kelly, Christopher Madden, Jennifer Richards, David Rudnick, Jemma Stachelek, and Tiffany G. Troxler. 2018. Salinity pulses interact with seasonal dry-down to increase ecosystem carbon loss in marshes of the Florida Everglades. Ecological Applications 28: 2092-2108. DOI: 10.1002/eap.1798 Dataset Keywords inorganic nutrients salinity alkalinity chloride dissolved organic carbon ph ammonium sulfate total dissolved nitrogen soluable dissolved phosphorus total dissolved phosphorus sulfide FCE FCE LTER Florida Coastal Everglades LTER ecological research long-term monitoring Nutrients Sea level rise Saltwater intrusion porewater Peat collapse Saltwater Intrusion Sea level rise Data Submission Date: 2018-08-02 Dataset Contact Position: Information Manager Organization: Florida Coastal Everglades LTER Program Address: Florida International University University Park OE 148 Miami, FL 33199 USA Phone: 305-348-6054 Fax: 305-348-4096 Email: fcelter@fiu.edu URL: http://fcelter.fiu.edu Dataset Submission Date 2018-08-02