gov.noaa.nodc:0219938 eng utf8 dataset NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NOAA Contact Information Information for contacts at NCEI. information custodian 2026-07-14T14:56:01Z ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Rates of denitrification and porewater nutrient concentrations at a saltmarsh in Alabama from 2015-04 to 2016-10 (NCEI Accession 0219938) 2020-09-30 publication 2020-09-08 creation NOAA National Centers for Environmental Information gov.noaa.nodc:0219938 NCEI Archive Management System 0219938 NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information publisher Lei Hu Dauphin Island Sea Lab (DISL) lhu@disl.org https://www.disl.edu/ HTTPS Dauphin Island Sea Lab (DISL) website Institution web page information resourceProvider Dauphin Island Sea Lab (DISL) https://www.disl.edu/ HTTPS Dauphin Island Sea Lab (DISL) website Institution web page information resourceProvider Behzad Mortazavi University of Alabama (UA) bmortazavi@ua.edu principalInvestigator Mortazavi, Behzad University of Alabama author Mason, Olivia U. Florida State University author Dauphin Island Sea Lab (DISL) https://www.disl.edu/ HTTPS Dauphin Island Sea Lab (DISL) website Institution web page information contributor tableDigital This dataset is generated from a study of a saltmarsh on Dauphin Island (30˚15.43′N, 88˚07.438′W) that is dominated by Spartina alterniflora and is interspersed with Juncus roemerianus. Tides are diurnal with mean tidal amplitude of less than 0.5 m. Replicate sediment cores (95 mm ID; n=5) were collected from Spartina alterniflora and Juncus roemerianus dominated sediments during the April 2015 to October 2016 period. Each core was sectioned between the 0-2 and 5-7 intervals and homogenized. Denitrification rates were measured following the acetylene inhibition technique. Porewater nutrient concentrations were periodically collected from triplicate sippers placed in Juncus roemerianus and Spartina dominated patches. Sippers were equipped with a 5-cm sampling window (centered at 10 cm depth). In May and August 2015 additional sediment cores were collected from the Spartina alterniflora and Juncus roemerianus patches and brought back to the laboratory for profiling of the porewater hydrogen sulfide concentrations. Coastal salt marshes are some of the most productive ecosystems on Earth, providing numerous services such as soil carbon storage, flood protection and nutrient filtering, several of which are mediated by the sediment microbiome associated with marsh vegetation. Our study site provided a unique opportunity to sample sediments from Spartina alterniflora and Juncus roemerianus patches collocated at the same elevation in a Gulf of Mexico salt marsh. This mixed marsh allowed us to test the hypothesis each plant type’s unique microbial community would translate to different denitrification rates. We measured rates of denitrification and porewater nutrient concentrations as well porewater hydrogen sulfides and demonstrated that denitrification rates were significantly higher in Juncus roemerianus compared to Spartina alterniflora and because these samples were collected from sediments associated with vegetation at the same elevation with respect to sea level we demonstrated plant diversity as opposed to inundation cycle influence marsh nitrogen removal. Funding Agency: National Science Foundation completed historicalArchive NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information pointOfContact asNeeded https://www.ncei.noaa.gov/access/metadata/landing-page/bin/gfx?id=gov.noaa.nodc:0219938 Preview graphic PNG 0219938 NCEI ACCESSION NUMBER 2020-08-28 publication AMMONIUM (NH4) DEPTH - OBSERVATION Hydrogen Sulfide (H2S) NITRATE NITRITE phosphate theme NODC DATA TYPES THESAURUS sediment sampler - corer instrument NODC INSTRUMENT TYPES THESAURUS in situ laboratory analyses theme NODC OBSERVATION TYPES THESAURUS Dauphin Island Sea Lab dataCentre NODC COLLECTING INSTITUTION NAMES THESAURUS Dauphin Island Sea Lab dataCentre NODC SUBMITTING INSTITUTION NAMES THESAURUS Coastal Waters of Alabama place NODC SEA AREA NAMES THESAURUS oceanography theme WMO_CategoryCode 2012-09-15 publication Collaborative Research: Engineering salt marsh restoration to maximize denitrification - elevation and species interactions project Originator Project Keywords EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > AMMONIA EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NITRATE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NITRITE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > PHOSPHATE theme Global Change Master Directory (GCMD) Science Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian Ammonium (Sipper Nutrients) DEPTH (Pot DNF) DNitrate (Sipper Nutrients) Date (H2S Profiles)) Date (Pot DNF) Date (Sipper Nutrients) Depth (H2S Profiles) Hydrogen Sulfide (H2S Profiles) Nitrite (Sipper Nutrients) Phosphate (Sipper Nutrients) Potential Denitrification (Pot DNF) Replicate (Pot DNF) Replicate (Sipper Nutrients) Veg Type (H2S Profiles) Veg Type (Pot DNF) Veg Type (Sipper Nutrients) theme Originator Theme Names SEDIMENT CORERS > SEDIMENT CORERS instrument Global Change Master Directory (GCMD) Instrument Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian A cut off syringe whose internal diameter is 95 mm and the length is 10 cm Observed Skalar SAN+ Autoanalyzere documentation observation observed instrument Originator Instrument Keywords OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > GULF OF AMERICA OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > GULF OF MEXICO place Global Change Master Directory (GCMD) Location Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian 5B583E Send2NCEI Submission Package ID accessLevel: public otherRestrictions Cite as: Mortazavi, Behzad; Mason, Olivia U. (2020). Rates of denitrification and porewater nutrient concentrations at a saltmarsh in Alabama from 2015-04 to 2016-10 (NCEI Accession 0219938). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0219938. Accessed [date]. Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. 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Contact NCEI for other distribution options and instructions. Originator data format 0.24 https://www.ncei.noaa.gov/archive/accession/0219938 HTTPS Web browser NCEI Dataset Landing Page Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/archive/accession/oas/219938 HTTPS Web browser Descriptive Information Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/archive/accession/download/219938 HTTPS Web browser HTTPS Navigate directly to the URL for data access and direct download. download ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0160/0219938/ FTP Any FTP client FTP These data are available through the File Transfer Protocol (FTP). FTP is no longer supported by most internet browsers. You may copy and paste the FTP link to the data into an FTP client (e.g., FileZilla or WinSCP). download dataset NCEI Accession 0219938 v1.1 was published. 2020-09-30T19:05:15Z NCEI Accession 0219938 v1.1 publication https://www.ncei.noaa.gov/archive/accession/0219938/1.1 HTTPS NCEI Accession 0219938 v1.1 published 2020-09-30T19:05:15Z download dataset Parameter or Variable: Date (Pot DNF) (measured); Units: date when samples were collected; Observation Category: Observed; Sampling Instrument: documentation only - no instrument type Parameter or Variable: Veg Type (Pot DNF) (measured); Units: location that the samples where pore water nutrients were collected from; Observation Category: in situ; Sampling Instrument: observed; Sampling and Analyzing Method: Samples were collected from sediment patches of Juncus roemerianus (Juncus) or Spartina alterniflora (Spartina). Parameter or Variable: Replicate (Pot DNF) (measured); Units: Replicate of samples; Observation Category: in situ; Sampling Instrument: documentation Parameter or Variable: DEPTH (Pot DNF) (measured); Units: centimeter; Observation Category: in situ; Sampling Instrument: Observed; Sampling and Analyzing Method: the sample depth from which the sediments were collected from with 0 representing the 0-2 cm depth, and 5 representing the 5-7 cm depth interval. Parameter or Variable: Potential Denitrification (Pot DNF) (measured); Units: micromoles of nitrogen (N) produced per kilogram dry sediment per square meter per hour; Observation Category: laboratory analysis; Sampling Instrument: A cut off syringe whose internal diameter is 95 mm and the length is 10 cm; Sampling and Analyzing Method: Replicate sediment cores (95 mm ID; n=5) were collected from Spartina and Juncus dominated sediments during the April 2015 to October 2016 period. Each core was sectioned between the 0-2 and 5-7 intervals and homogenized. Denitrification rates were measured following the acetylene inhibition technique. Twenty grams of sediments from each core and each depth and filtered site water were added to serum vials and amended with nitrate to a concentration of 100 micromolar. Samples were sealed with a butyl rubber stopper, capped and flushed with N2 gas for 10 min. After the addition of C2H2 (10 % v/v) and a 1-h incubation, headspace gas samples were injected into evacuated 12 mL Exetainer vials and nitrous oxide production was quantified with a Shimadzu GC-2014 with an electron capture detector (GC-ECD) within 24 h. Nitrous oxide standards of known concentrations were used to quantify the nitrous oxide concentrations. Parameter or Variable: Date (H2S Profiles) (measured); Units: date when samples were collected; Observation Category: Observed; Sampling Instrument: documentation Parameter or Variable: Veg Type (H2S Profiles) (measured); Units: location that the samples where pore water nutrients were collected from; Observation Category: in situ; Sampling Instrument: Observed; Sampling and Analyzing Method: Samples were collected from sediment patches of Juncus roemerianus (Juncus) or Spartina alterniflora (Spartina). Parameter or Variable: Depth (H2S Profiles) (measured); Units: mm; Observation Category: in situ; Sampling Instrument: documentation; Sampling and Analyzing Method: the sample depth in units of mm that measurements were made at Parameter or Variable: Hydrogen Sulfide (H2S Profiles) (measured); Units: the concentration of hydrogen sulfide in units of micromoles per liter; Observation Category: laboratory analysis; Sampling Instrument: A cut off syringe whose internal diameter is 95 mm and the length is 10 cm; Sampling and Analyzing Method: In May and August 2015 additional sediment cores were collected from the Spartina and Juncus patches and brought back to the laboratory for profiling of the porewater hydrogen sulfide concentrations. Cores were kept at in situ temperature and submerged in site water that was maintained normoxic. Hydrogen sulfide (measured as HS-) concentrations were determined with a Unisense microelectrode system with H2S (H2S-500) sensor calibrated according to manufacturer’s instructions. Concentrations were recorded at the sediment–water interface to a depth of 20 mm at 1 mm intervals with a micromanipulator in each profile. Standards were prepared according to the manufacturer and used to calibrate the sensors. Parameter or Variable: Date (Sipper Nutrients) (measured); Units: documentation; Observation Category: in situ; Sampling Instrument: observed Parameter or Variable: Veg Type (Sipper Nutrients) (measured); Units: location that the samples where pore water nutrients were collected from; Observation Category: in situ; Sampling Instrument: Observed; Sampling and Analyzing Method: Samples were collected from sediment patches of Juncus roemerianus (Juncus) or Spartina alterniflora (Spartina). Parameter or Variable: Replicate (Sipper Nutrients) (measured); Units: Replicate of samples; Observation Category: in situ; Sampling Instrument: observation Parameter or Variable: Nitrate (Sipper Nutrients) (measured); Units: concentration of porewater nitrate in units of micromoles per liter; Observation Category: laboratory analysis; Sampling Instrument: Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewater nutrient concentrations were periodically collected from triplicate sippers placed in Juncus and Spartina dominated patches. Sippers were equipped with a 5-cm sampling window (centered at 10 cm depth) of porous plastic (Porex, 25-40 µm pore size). Prior to sampling, the sippers were purged of water and flushed with N2 gas to maintain anoxia. Samples were then withdrawn with a syringe, filtered through GF/F filters, kept on ice and returned to the lab where they remained frozen until analysis. Nitrate, ammonium and phosphate concentrations were analyzed with standard wet chemical techniques modified for the Skalar SAN+ Autoanalyzer calibrated according to the manufacturer. Parameter or Variable: Phosphate (Sipper Nutrients) (measured); Units: concentration of porewater phosphate in units of micromoles per liter; Observation Category: laboratory analysis; Sampling Instrument: Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewater nutrient concentrations were periodically collected from triplicate sippers placed in Juncus and Spartina dominated patches. Sippers were equipped with a 5-cm sampling window (centered at 10 cm depth) of porous plastic (Porex, 25-40 µm pore size). Prior to sampling, the sippers were purged of water and flushed with N2 gas to maintain anoxia. Samples were then withdrawn with a syringe, filtered through GF/F filters, kept on ice and returned to the lab where they remained frozen until analysis. Nitrate, ammonium and phosphate concentrations were analyzed with standard wet chemical techniques modified for the Skalar SAN+ Autoanalyzer calibrated according to the manufacturer. Parameter or Variable: Nitrite (Sipper Nutrients) (measured); Units: lconcentration of porewater nitrite in units of micromoles per liter; Observation Category: laboratory analysis; Sampling Instrument: Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewater nutrient concentrations were periodically collected from triplicate sippers placed in Juncus and Spartina dominated patches. Sippers were equipped with a 5-cm sampling window (centered at 10 cm depth) of porous plastic (Porex, 25-40 µm pore size). Prior to sampling, the sippers were purged of water and flushed with N2 gas to maintain anoxia. Samples were then withdrawn with a syringe, filtered through GF/F filters, kept on ice and returned to the lab where they remained frozen until analysis. Nitrate, ammonium and phosphate concentrations were analyzed with standard wet chemical techniques modified for the Skalar SAN+ Autoanalyzer calibrated according to the manufacturer. Parameter or Variable: Ammonium (Sipper Nutrients) (measured); Units: concentration of porewater nitrite in units of micromoles per liter; Observation Category: laboratory analysis; Sampling Instrument: Skalar SAN+ Autoanalyzer; Sampling and Analyzing Method: Porewater nutrient concentrations were periodically collected from triplicate sippers placed in Juncus and Spartina dominated patches. Sippers were equipped with a 5-cm sampling window (centered at 10 cm depth) of porous plastic (Porex, 25-40 µm pore size). Prior to sampling, the sippers were purged of water and flushed with N2 gas to maintain anoxia. Samples were then withdrawn with a syringe, filtered through GF/F filters, kept on ice and returned to the lab where they remained frozen until analysis. Nitrate, ammonium and phosphate concentrations were analyzed with standard wet chemical techniques modified for the Skalar SAN+ Autoanalyzer calibrated according to the manufacturer. asNeeded Metadata are developed, maintained and distributed by NCEI. Updates are performed as needed to maintain currentness. NOAA National Centers for Environmental Information custodian sediment sampler - corer sediment sampler - corer sediment coring device gravity or other coring device used to collect surfacial and near-surficial sediment samples