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Flux data from the Peat Collapse-Saltwater Intrusion Field Experiment within Everglades National Park, collected from October 2014 to September 2016


At a Glance


(Zip file containing 2 files)

Authors: Benjamin Wilson, Tiffany Troxler
Time period: 2014-10-01 to 2016-10-01
Package id: knb-lter-fce.1224.1
Dataset id: FCE1224

How to cite:
Wilson, B., T. Troxler. 2018. Flux data from the Peat Collapse-Saltwater Intrusion Field Experiment within Everglades National Park, collected from October 2014 to September 2016. Environmental Data Initiative. https://doi.org/10.6073/pasta/a84048bfa2552499fad8d80f313db008. Dataset accessed 2024-03-29.

Geographic Coverage
This data set contains the following files.

FCE1224_FieldFlux_CO2.txt
CO2 measurements from the Peat Collapse Experiment
Attribute table details     Download

FCE1224_FieldFlux_CH4.txt
CH4 measurements from the Peat Collapse Experiment
Attribute table details     Download



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Detailed Metadata


  • Dataset Creator(s)
    • 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/

  • 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 ecosystem flux measurements were taken from a brackish water and freshwater marsh. Ecosystem flux was measured 24 hours after dosing. Measurements occurred from Oct 2014 - Sep 2016. Ecosystem flux measured includes gross ecosyetem production, ecosystem respiration of CO2, net ecosystem production, and ecosystem respiration of CH4. 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. Ecological Applications. Accepted.
  • Geographic Coverage
    Study Extent Description


    Bounding Coordinates
    Coordinates indicate the center of our plots at a brackish water and freshwater marsh within Everglades National Park
    N: 25.22, S: 25.22, E: -80.84, W: -80.84

    Florida Coastal Everglades LTER Study Area: South Florida, Everglades National Park, and Florida Bay
    N: 25.761, S: 24.913, E: -80.490, W: -81.078

  • Attributes
    • Data Table:   CO2 measurements from the Peat Collapse Experiment
      Attribute Name:
      Site.CO2
      Attribute Label:
      Site.CO2
      Attribute Definition:
      Site name
      Storage Type:
      Text
      Measurement Scale:
      BW = Brackish water
      FW = Freshwater
      Missing Value Code:
       

      Attribute Name:
      Plot.CO2
      Attribute Label:
      Plot.CO2
      Attribute Definition:
      Plot number
      Storage Type:
      Text
      Measurement Scale:
      Plot number
      Missing Value Code:
       

      Attribute Name:
      Treatment.CO2
      Attribute Label:
      Treatment.CO2
      Attribute Definition:
      Treatment label
      Storage Type:
      Text
      Measurement Scale:
      Control = Ambient water added
      Treatment = saltwater added
      Missing Value Code:
       

      Attribute Name:
      Date.CO2
      Attribute Label:
      Date.CO2
      Attribute Definition:
      Date
      Storage Type:
      datetime
      Measurement Scale:
      Missing Value Code:
       

      Attribute Name:
      wet.or.dry.CO2
      Attribute Label:
      wet.or.dry.CO2
      Attribute Definition:
      Wet means water was covering soil surface during measurement, dry means water was below soil surface during measurement
      Storage Type:
      Measurement Scale:
      Wet means water was covering soil surface during measurement, dry means water was below soil surface during measurement
      Missing Value Code:
       

      Attribute Name:
      GEP.CO2
      Attribute Label:
      GEP.CO2
      Attribute Definition:
      Gross ecosystem Production (grams of Carbon per meters squared per month)
      Storage Type:
      data
      Measurement Scale:
      Units: gramsPerMeterSquaredPerMonth
      Number Type: real
      Missing Value Code:
      NA (Not available)

      Attribute Name:
      ER.CO2
      Attribute Label:
      ER.CO2
      Attribute Definition:
      Ecosystem Respiration (grams of carbon per meter squared per month)
      Storage Type:
      data
      Measurement Scale:
      Units: gramsPerMeterSquaredPerMonth
      Number Type: real
      Missing Value Code:
      NA (Not available)

      Attribute Name:
      NEP.CO2
      Attribute Label:
      NEP.CO2
      Attribute Definition:
      Net ecosystem Production (grams of carbon per meter squared per month)
      Storage Type:
      data
      Measurement Scale:
      Units: gramsPerMeterSquaredPerMonth
      Number Type: real
      Missing Value Code:
      NA (Not available)


    • Data Table:   CH4 measurements from the Peat Collapse Experiment
      Attribute Name:
      Site.CH4
      Attribute Label:
      Site.CH4
      Attribute Definition:
      Site name
      Storage Type:
      Text
      Measurement Scale:
      BW = Brackish water
      FW = Freshwater
      Missing Value Code:
       

      Attribute Name:
      Plot.CH4
      Attribute Label:
      Plot.CH4
      Attribute Definition:
      Plot number
      Storage Type:
      Text
      Measurement Scale:
      Plot number
      Missing Value Code:
       

      Attribute Name:
      Treatment.CH4
      Attribute Label:
      Treatment.CH4
      Attribute Definition:
      Treatment label
      Storage Type:
      Text
      Measurement Scale:
      Control = Ambient water added
      Treatment = saltwater added
      Missing Value Code:
       

      Attribute Name:
      Date.CH4
      Attribute Label:
      Date.CH4
      Attribute Definition:
      Date
      Storage Type:
      datetime
      Measurement Scale:
      Missing Value Code:
       

      Attribute Name:
      wet.or.dry.CH4
      Attribute Label:
      wet.or.dry.CH4
      Attribute Definition:
      Wet means water was covering soil surface during measurement, dry means water was below soil surface during measurement
      Storage Type:
      Text
      Measurement Scale:
      Wet means water was covering soil surface during measurement, dry means water was below soil surface during measurement
      Missing Value Code:
       

      Attribute Name:
      CH4
      Attribute Label:
      CH4
      Attribute Definition:
      Ecosystem Respiration of CH4 (milligrams of methane per meter squared per day)
      Storage Type:
      data
      Measurement Scale:
      Units: milligramsPerMeterSquaredPerDay
      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
    LI-COR 840

    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.

    Instrumentation
    HP 5890 Gas Chromatograph

    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
    Within each plot, one 0.5 x 0.5 m polycarbonate collar was permanently installed 10-cm into the soil and extended 5-cm above the soil surface for ecosystem C flux measurements. Each collar had eight 2.5-cm diameter holes at the soil surface level to allow for natural flow of water when measurements were not occurring. Plot-scale CO2 exchange was measured monthly using a transparent static chamber (0.25 m2 x 1.5 m; after Neubauer et al. 2000, Wilson et al. 2015). Prior to measurements being taken, each hole in the collar was plugged with a rubber stopper, the chamber was placed into a lip in the collar and sealed, and the system was allowed to equilibrate for 2 minutes. Measurements were then made for 3 minutes each in full light and in the dark, with the chamber lid removed in between each measurement to allow the chamber to return to atmospheric conditions (LI-COR 840, Lincoln, NE; Wilson et al. in press). All measurements made at each site were taken within ± 3 hours of solar noon and on the same day. Missing measurements occurred when there was either equipment failure (BW site, Jul – Aug 2016) or when water levels were higher than the boardwalk (FW site, Dec 2015 – Apr 2016), limiting access to the plots.


    Method Step

    Description
    Methane exchange measurements were conducted monthly from October 2014 – February 2016. After the dark CO2 exchange measurement was conducted, the chamber was kept in the dark and resealed for 20 minutes. Air from the chamber was continually pumped through a closed loop with a sampling port attached. Gas samples were taken at 0, 10, and 20 minutes using a 60-mL syringe to withdraw 25-mL of air from the sampling port placed in line with the chamber. The sample was then injected into a 20-mL evacuated vial. Methane concentrations were determined using a gas chromatograph (Hewlett-Packard 5890, Palo Alto, CA, USA), and the change in concentration over time was used to calculate the flux.


    Quality Control
    Data are QA/QC'ed by visually plotting and inspecting data and removing any data points that are plus or minus two standard deviations away from the average
  • Distribution and Intellectual Rights
    Online distribution
    http://fcelter.fiu.edu/perl/public_data_download.pl?datasetid=FCE1224_FieldFlux_CO2.txt
    Data Submission Date:  2018-08-17

    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 2024. 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

  • Keywords
    sea level, carbon flux, salinity, ecosystem respiration, carbon dioxide, methane, FCE, Florida Coastal Everglades LTER, ecological research, long-term monitoring, flux, Sea level rise, Saltwater intrusion, Peat collapse, net ecosystem production, gross ecosystem production
  • Dataset Contact
    • Name: 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/

    • 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

  • Data Table and Format
    Data Table:  CO2 measurements from the Peat Collapse Experiment

    Entity Name:
    FCE1224_FieldFlux_CO2.txt
    Entity Description:
    CO2 measurements from the Peat Collapse Experiment
    Object Name:
    FCE1224_FieldFlux_CO2.txt
    Number of Header Lines:
    1
    Attribute Orientation:
    column
    Field Delimiter:
    ,
    Number of Records:
    466

    Data Table:  CH4 measurements from the Peat Collapse Experiment

    Entity Name:
    FCE1224_FieldFlux_CH4.txt
    Entity Description:
    CH4 measurements from the Peat Collapse Experiment
    Object Name:
    FCE1224_FieldFlux_CH4.txt
    Number of Header Lines:
    1
    Attribute Orientation:
    column
    Field Delimiter:
    ,
    Number of Records:
    160