I. Data Set Descriptors A. Title: null. 2023. Characterizing the ecology and soil biogeochemistry of wetland transition zones along the Satilla River Estuary, GA, USA.. Georgia Coastal Ecosystems LTER Data Catalog (data set MSH-GCET-2305; /data/MSH-GCET-2305) B. Accession Number: MSH-GCET-2305 C. Description 1. Originator(s): null 2. Abstract: The location of salinity gradients in coastal wetlands, from tidal freshwater sourced from riverine inputs to polyhaline sourced from saline ocean water, is subject to natural and unnatural shifts due to climactic patterns such as changes in discharge, sea-level rise (SLR), and alterations to hydrology. Increased inundation in of saltwater in the Satilla River has resulted in conversions of plant communities from fresh or brackish to salt tolerant species that has implications for belowground soil biogeochemistry. These data explore the translation of aboveground properties to soil properties in transitional wetlands in poly-, meso-, and oligohaline regions and across elevation gradients from levee to platform in the Satilla River Estuary, GA by characterizing the ecological communities and soil size fractionation, total organic carbon content (TOC) and composition (delta13C). 3. Study Type: Graduate Thesis Study 4. Study Themes: Marsh Ecology, Organic Matter/Decomposition 5. LTER Core Areas: Organic Matter 6. Georeferences: geographic coordinates as data columns 7. Submission Date: May 03, 2023 D. Keywords: Angiospermae, Asteraceae, Asterales, Asteranae, biogeochemistry, brackish, carbon, Caryophyllales, Caryophyllanae, Cladium jamaicense, Cyperaceae, Embryophyta, freshwater, GCE, Georgia, Georgia Coastal Ecosystems, isotope analysis, Juncaceae, Juncus effusus, Juncus roemerianus, Lilianae, LTER, Magnoliopsida, Organic Matter, plant communities, plant cover, Plantae, Pluchea odorata, Poaceae, Poales, Polygonaceae, salinity, salt marshes, Sapelo Island, Satilla River, sediments, soil carbon, Spartina alterniflora, Spartina cynosuroides, Spermatophytina, stable isotopes, Streptophyta, Tracheophyta, UGA, USA, Viridaeplantae, Viridiplantae, wetlands II. Research Origin Descriptors A. Overall Project Description 1. Project Title: Georgia Coastal Ecosystems LTER - IV 2. Principal Investigators: Name: Merryl Alber Address: Dept. of Marine Sciences University of Georgia Athens, Georgia 30602-3636 Country: USA Email: malber@uga.edu 3. Funding Period: Feb 01, 2019 to Jan 31, 2025 4. Objectives: The GCE-LTER project has four goals. 1) Track environmental and human drivers that can cause perturbations in our focal ecosystems. This will be accomplished this through continuing long-term measurements of climate, water chemistry, oceanic exchange, and human activities on the landscape. 2) Describe temporal and spatial variability in physical, chemical, geological and biological characteristics of the study system (coastal wetland complexes) and how they respond to external drivers. This will be accomplished through field monitoring in combination with remote sensing and modeling. 3) Characterize the ecological responses of intertidal marshes to disturbance. This will be accomplished by ongoing monitoring and experimental work to evaluate system responses to major perturbations in three key marsh habitats (changes in inundation and predator exclusion in Spartina-dominated salt marshes; increases in salinity in fresh marshes; changes in runoff in high marshes), by implementing standardized experimental disturbances along salinity and elevation gradients, and by tracking responses to natural disturbances. 4) Evaluate ecosystem properties at the landscape level (habitat distribution, net and gross primary production, C budgets) and assess the cumulative effects of disturbance on these properties. The project will also develop relationships between drivers and response variables, which can be used to predict the effects of future changes. This will be accomplished through a combination of data synthesis, remote sensing and modeling. 5. Abstract: The Georgia Coastal Ecosystems (GCE) Long Term Ecological Research (LTER) program, based at the University of Georgia Marine Institute on Sapelo Island, Georgia, was established in 2000 to study long-term change in coastal ecosystems. Estuaries (places where salt water from the ocean mixes with fresh water from the land) and their adjacent marshes provide food and refuge for fish, shellfish and birds; protect the shoreline from storms; help to keep the water clean; and store carbon. The GCE LTER researchers study marshes and estuaries to understand how these ecosystems function, to track how they change over time, and to predict how they might be affected by future changes in climate and human activities. They accomplish this by tracking the major factors that can cause long-term change in coastal areas (e.g. sea level, rainfall, upstream development), and measuring the effects of these factors on the study site. They also conduct focused studies to assess how key marsh habitats will respond to major changes expected in the future, including large-scale experiments to evaluate the effects of a) increases in the salinity of the water that floods freshwater marshes (mimicking drought and/or sea level rise), b) changes in water runoff from land into the upland marsh border (mimicking drought or upland development), and c) exclusion of larger organisms in the salt marsh (mimicking long-term declines in predators). During this award they will initiate additional studies to systematically evaluate how coastal wetlands respond to disturbances. Disturbances, or disruptions in the environment, are particularly important to understand in the context of long-term background changes such as increasing sea level, and GCE researchers are working to assess the cumulative effects of multiple disturbances on the landscape. The GCE education and outreach program works to share an understanding of coastal ecosystems with teachers and students, coastal managers, citizen scientist and the general public. 6. Funding Source: NSF OCE 1832178 B. Sub-project Description 1. Site Description a. Geographic Location: CentralCst -- Central Georgia Coast, Georgia, USA Coordinates: CentralCst -- NW: 081 45 35.15 W, 31 46 16.28 N NE: 081 07 09.45 W, 31 46 16.28 N SE: 081 07 09.45 W, 30 53 33.76 N SW: 081 45 35.15 W, 30 53 33.76 N b. Physiographic Region: CentralCst -- unspecified c. Landform Components: CentralCst -- unspecified d. Hydrographic Characteristics: CentralCst -- unspecified e. Topographic Attributes: CentralCst -- unspecified f. Geology, Lithology and Soils: CentralCst -- unspecified g. Vegetation Communities: CentralCst -- unspecified h. History of Land Use and Disturbance: none recorded i. Climate: Climate summary for Sapelo Island, Georgia, based on NWS data from 1980-2010: Daily-aggregated Values: Mean (sample standard deviation) mean air temperature: 20.09°C (7.28°C) minimum air temperature: 15.02°C (7.96°C) maximum air temperature: 24.82°C (6.98°C) total precipitation: 3.26mm (10.3mm) Yearly-aggregated Daily Values: Mean (sample standard deviation) total precipitation (1980-2010): 1124mm (266mm) 2. Experimental or Sampling Design a. Design Characteristics: Sampling sites were selected in poly-, meso-, and oligohaline regions within the Satilla River Estuary marshes. Each salinity region had two replicates. ). Each site was further sampled at levee and platform locations within the marsh to capture the combined effects of the elevation gradient and distance from creekbank edge. b. Permanent Plots: The study area consisted of the core location and adjacent 1 m^2 quadrat. Levee locations were approximately ~ 10 m from the creekbank edge and platform locations were ~ 200 m from the creekbank edge. c. Data Collection Duration and Frequency: Study plots were established at poly- and mesohaline regions in March 2021 and soil cores and RTK measurements were taken at this time. Cores were collected using minimally invasive techniques in 100 cm long, 10.5 cm OD, acrylic core barrels. Oligohaline plots were established in August 2021 and both soil cores and RTK measurements were taken. Plant and macroinvertebrate sampling also occurred in August 2021 within 1 m^2 quadrats. Porewater chemistry measurements were taken just adjacent to the quadrats with Push Point samplers. Water was collected in 60 mL syringes and measurements were taken same day in lab. Beginning of Observations: Aug 10, 2020 End of Observations: Apr 17, 2023 3. Research Methods a. Field and Laboratory Methods: Method 1: Plant percent cover, canopy height and macroinvertebrate abundance -- Plant species were identified in the field and corroborated post sampling. Percent cover of each species was determined visually within a randomly placed 1 m^2 quadrat. The height of the tallest 5 individuals of each species was measured to determine canopy height. Macroinvertebrate organisms (crabs, snails, mussels, and clams) were counted within the 1 m^2 quadrat both in/on the surface soil and on the plants. No mussels and clams were found in any sites so were not included in the data sheet. Method 2: RTK coordinates and elevation -- GPS coordinates and elevation relative to NAVD88 was measured starting at the levee location where the core was collected and subsequently measured at the platform approximately 200 m into the interior. Method 3: Porewater chemistry -- Porewater samples were collected in 60 mL syringes using Push Point samplers and stored on ice in the field until processing. Push Point samplers pulled porewater from 89.5 cm depth, but where water collection was unsuccessful at that depth, the Push Point was adjusted, and the depth of collection was recorded. On the same day of collection, redox potential (Eh) was measured on unfiltered samples to minimize oxidation (Thermo Scientific platinum Redox Probe). Approximately 4 mL of sample was filtered through 45 um glass fiber filters (GFFs) into 8 mL HDPE bottles containing 4 mL of 0.1 M zinc acetate and stored in the refrigerator to be transported to the lab at UGA for sulfide analysis. The remaining sample was filtered into 20 mL HDPE bottles and salinity (refractometer) and pH (Thermo Scientific pH Probe) were measured immediately before the samples were refrigerated to be transported to the lab for ammonium analysis. Sulfide concentrations were measured in refrigerated samples spectrophotometrically using the Cline method within two weeks of collection (Shimadzu Spectrophotometer; Cline, 1969). Samples for ammonium analysis were frozen (-20 deg C) until analysis using the colorimetric indophenol blue method (Shimadzu Spectrophotometer; Solórzano, 1969). Method 4: Soil organic matter -- Cores 60 - 80 cm long were collected at each site in acrylic core barrels with an outer diameter of approximately 10.7 cm. Cores were transported back to UGA where they were refrigerated and cut within a few days of collection. The cores were cut laterally and one half was separated into 1 cm horizons in the top 10 cm and 2 cm horizons to the bottom of the core in the following intervals to balance downcore resolution and analytical resources: every 2 cm from 10 – 32 cm, every 5cm from 32 – 50 cm and every 10 cm from 50 cm to the bottom. Between 2 – 10 g of freeze-dried sample was weighed into an Erlenmeyer flask with a 30 g soil: 100 mL solution ratio of 5% sodium hexametaphosphate solution (weight/volume). Samples were agitated for 18 h to break up aggregates before being passed through 1 mm and 53 um sieves to separate coarse particles ( >1 mm), fine particles (1 mm – 53 um), and mineral particles (<53 um) (Bradford et al., 2008; Cambardella & Elliot, 1993; Lavallee et al., 2020). Fractions were frozen at -80 °C, freeze-dried, and re-weighed before homogenization with a Retsch Mixer Mill 200. Ground samples were packed into silver cups and inorganic carbon was removed by hydrochloric acid (HCl) fumigation (Hedges et al. 2000; Hedges and Stern 1984). Total organic carbon (TOC) and del 13C was measured on select soil horizons of each fraction and bulk (unsieved) soil downcore for each soil core. The percent TOC and isotopic composition (delta13C) in each soil fraction was analyzed by The Marine Biological Lab’s Stable Isotope Laboratory using a Europa 20-20 continuous-flow isotope ratio mass spectrometer interfaced with a Europa ANCA-SL elemental analyzer. The analytical precision based on replicate analyses of isotopically homogeneous international standards is +/- 0.1 ‰ for delta 13C measurements, and about 1% on the C measurements. Stable isotope values were reported per mil (‰) relative to a PBD standard. b. Protocols: Method 1: none Method 2: none Method 3: none Method 4: none c. Instrumentation: Method 1: none Method 2: RTK GPS Manufacturer: Trimble (Model: R6) Parameter: Elevation (Accuracy: 20mm + 1 ppm RMS, Readability: 1mm, ) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Parameter: Latitude (Accuracy: 10 mm + 1 ppm RMS, Readability: 1mm, Range: 0-90 degrees) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Parameter: Longitude (Accuracy: 10 mm + 1 ppm RMS, Readability: 1mm, Range: 0-180 degrees) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Method 3: Thermo Scientific platinum Redox Probe, Thermo Scientific pH Probe, refractometer, Shimadzu Spectrophotometer Method 4: Retsch Mixer Mill 200, Europa 20-20 continuous-flow isotope ratio mass spectrometer d. Taxonomy and Systematics: Method 1: not applicable Method 2: not applicable Method 3: not applicable Method 4: not applicable e. Speclies List: f. Permit History: Method 1: not applicable Method 2: not applicable Method 3: not applicable Method 4: not applicable 4. Project Personnel a. Personnel: 1: Gabriella Bliss Giordano 2: Amanda C. Spivak b. Affiliations: 1: University of Georgia 2: University of Georgia, Athens, Georgia III. Data Set Status and Accessibility A. Status 1. Latest Update: 16-Nov-2023 2. Latest Archive Date: 18-May-2023 3. Latest Metadata Update: 16-Nov-2023 4. Data Verification Status: Reviewed by IM B. Accessibility 1. Storage Location and Medium: Stored at GCE-LTER Data Management Office Dept. of Marine Sciences Univ. of Georgia Athens, GA 30602-3636 USA on media: electronic data download (WWW) or compact disk 2. Contact Person: Name: Adam Sapp Address: Department of Marine Sciences University of Georgia Athens, Georgia 30602 Country: USA Email: asapp@uga.edu 3. Copyright Restrictions: not copyrighted 4. Restrictions: This information is licensed under a Creative Commons Attribution 4.0 International License (see: https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) has an ethical obligation 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. a. Release Date: Affiliates: May 03, 2023, Public: May 03, 2025 b. Citation: Data provided by the Georgia Coastal Ecosystems Long Term Ecological Research Project, supported by funds from NSF OCE 1832178 (data set MSH-GCET-2305) c. Disclaimer: The user assumes all responsibility for errors in judgement based on interpretation of data and analyses presented in this data set. 5. Costs: free electronic data download via WWW, distribution on CD may be subject to nominal processing and handling fee IV. Data Structural Descriptors A. Data Set File 1. File Name: MSH-GCET-2305_SOM_1_0.CSV 2. Size: 696 records 3. File Format: ASCII text (comma-separated value format) 3a. Delimiters: single comma 4. Header Information: 5 lines of ASCII text 5. Alphanumeric Attributes: 6. Quality Control Flag Codes: Q = questionable value, I = invalid value, E = estimated value 7. Authentication Procedures: 8. Calculations: PercentMass: (Mass fraction)/(Mass Bulk) *100 9. Processing History: Software version: GCE Data Toolbox Version 3.9.10 (23-May-2022) Data structure version: GCE Data Structure 1.1 (29-Mar-2001) Original data file processed: SOM.txt (696 records) Data processing history: 08-May-2023: new GCE Data Structure 1.1 created ('newstruct') 08-May-2023: 696 rows imported from ASCII data file 'SOM.txt' ('imp_ascii') 08-May-2023: 13 metadata fields in file header parsed ('parse_header') 08-May-2023: data structure validated ('gce_valid') 08-May-2023: updated 1 metadata fields in the Dataset section(s) ('addmeta') 08-May-2023: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 08-May-2023: updated 57 metadata fields in the Dataset, Project, Site, Status, Study, Supplement section(s) ('addmeta') 18-May-2023: updated 1 metadata fields in the Dataset section(s) ('addmeta') 18-May-2023: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 18-May-2023: updated 57 metadata fields in the Dataset, Project, Site, Status, Study, Supplement section(s) ('addmeta') 16-Nov-2023: Descriptions of columns FullCoreID and CoreID edited; Units of column FullCoreID changed from 'Count' to 'none'; Units of column DepthHorizon changed from 'cm' to 'none';Variable Type of column SalinityRegion changed from 'text' to 'code'; Variable Type of column LocationID changed from 'text' to 'code'; Variable Type of column Fraction changed from 'text' to 'code ('ui_editor') 16-Nov-2023: updated 6 metadata fields in the Data section(s) ('addmeta') 16-Nov-2023: updated 15 metadata fields in the Status, Data sections to reflect attribute metadata ('updatecols') 16-Nov-2023: parsed and formatted metadata ('listmeta') B. Variable Information 1. Variable Name: column 1. FullCoreID column 2. CoreID column 3. SiteID column 4. SalinityRegion column 5. LocationID column 6. DepthHorizon column 7. MidDepth column 8. Fraction column 9. PercentCarbon column 10. Del13C column 11. PercentMass 2. Variable Definition: column 1. Project ID (NOAA CIG 2020) plus coreID column 2. CoreID column 3. Replicate site within each salinity region. column 4. Location within the marsh or distance from creekbank. column 5. Salinity region names used in manuscript. column 6. 1 cm and 2 cm horizons of the soil core. column 7. Mid depth of the depth horizons column 8. Size fraction of soil horizons. column 9. Total percent carbon in each fraction and the bulk sample measured by MBL Stable Isotope Lab. column 10. Stable carbon isotope signature measured by MBL Stable Isotope Lab. column 11. Percent mass of each fractions contribution to the bulk sample. 3. Units of Measurement: column 1. none column 2. none column 3. none column 4. none column 5. none column 6. none column 7. cm column 8. none column 9. % column 10. ppt column 11. % 4. Data Type a. Storage Type: column 1. string column 2. string column 3. string column 4. string column 5. string column 6. string column 7. floating-point column 8. string column 9. floating-point column 10. floating-point column 11. floating-point b. Variable Codes: SiteID: E = Estuarine, M = Mesohaline, F = Freshwater SalinityRegion: Polyhaline = Estuarine, Mesohaline = Mesohaline, Oligohaline = Freshwater LocationID: L = Levee, P = Platform Fraction: Coarse = >1mm, Fine = >53um, Mineral = <53um, Bulk = unseived sample c. Numeric Range: column 1. (none) column 2. (none) column 3. (none) column 4. (none) column 5. (none) column 6. (none) column 7. 0.5 to 91 column 8. (none) column 9. 0.31 to 39.9 column 10. -30.6 to -13.4 column 11. 0 to 100 d. Missing Value Code: 5. Data Format a. Column Type: column 1. text column 2. text column 3. text column 4. text column 5. text column 6. text column 7. numerical column 8. text column 9. numerical column 10. numerical column 11. numerical b. Number of Columns: 11 c. Decimal Places: column 1. 0 column 2. 0 column 3. 0 column 4. 0 column 5. 0 column 6. 0 column 7. 1 column 8. 0 column 9. 2 column 10. 1 column 11. 4 6. Logical Variable Type: column 1. free text (none) column 2. free text (none) column 3. coded value (none) column 4. coded value (none) column 5. coded value (none) column 6. free text (none) column 7. data (continuous) column 8. coded value (none) column 9. data (continuous) column 10. data (continuous) column 11. data (continuous) 7. Flagging Criteria: column 1. none column 2. none column 3. none column 4. none column 5. none column 6. none column 7. none column 8. none column 9. none column 10. none column 11. none C. Data Anomalies: V. Supplemental Descriptors A. Data Acquisition 1. Data Forms: 2. Form Location: 3. Data Entry Validation: B. Quality Assurance/Quality Control Procedures: C. Supplemental Materials: D. Computer Programs: E. Archival Practices: F. Publications: not specified G. History of Data Set Usage 1. Data Request History: not specified 2. Data Set Update History: none 3. Review History: none 4. Questions and Comments from Users: none