Metadata: Identification_Information: Citation: Citation_Information: Originator: Jennifer A. O'Keefe Suttles Originator: Meagan J. Eagle Originator: Rose M. Martin Originator: Serena Moseman-Valtierra Originator: Kevin D. Kroeger Publication_Date: 20220526 Title: Static chamber gas fluxes and carbon and nitrogen isotope content of age-dated sediment cores from a Phragmites wetland in Sage Lot Pond, Massachusetts, 2013-2015 Edition: 1.0 Geospatial_Data_Presentation_Form: tabular digital data Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9JM751N Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Other_Citation_Details: Suggested citation: O'Keefe Suttles, J.A., Eagle, M.J., Martin, R.M., Moseman-Valtierra, S., and Kroeger, K.D., 2022, Static chamber gas fluxes and carbon and nitrogen isotope content of age-dated sediment cores from a Phragmites wetland in Sage Lot Pond, Massachusetts, 2013-2015: U.S. Geological Survey data release, https://doi.org/10.5066/P9JM751N. Online_Linkage: https://doi.org/10.5066/P9JM751N Online_Linkage: https://www.sciencebase.gov/catalog/item/624b1752d34e21f827635bdf Description: Abstract: Coastal wetlands are major global carbon sinks; however, quantification of carbon flux can be difficult in these heterogeneous and dynamic ecosystems. To characterize spatial and temporal variability in a New England salt marsh, static chamber measurements of greenhouse gas (GHG) fluxes were compared among major plant-defined zones (high marsh dominated by Distichlis spicata and a zone of invasive Phragmites australis) during 2013 and 2014 growing seasons. Two sediment cores were collected in 2015 from the Phragmites zone to support previously reported core collections from the high marsh sites (Gonneea and others 2018). Collected cores were up to 70 cm in length with dry bulk density ranges from 0.04 to 0.33 grams per cubic centimeter and carbon content 22.4 to 46.6 percent. Gamma counting results for excess lead-210 were used to construct Constant Rate of Supply (CRS) age models to age-date individual depth intervals in the cores. Additionally, gamma counting results for other radionuclides, particularly cesium-137 gave further insight to evaluate how vertical accretion and carbon burial rates have changed during the past century. Gonneea, M.E., O'Keefe Suttles, J.A., and Kroeger, K.D., 2018, Collection, analysis, and age-dating of sediment cores from salt marshes on the south shore of Cape Cod, Massachusetts, from 2013 through 2014: U.S. Geological Survey data release, https://doi.org/10.5066/F7H41QPP. Purpose: The purpose of this study was to measure greenhouse gas fluxes across a seasonal time-scale and to determine sediment carbon content and sediment accumulation rates across contrasting plant-defined zones in order to model controls on GHG fluxes in a New England salt marsh. These data support research focused on understanding controls and scaling of carbon exchange in order to inform possible Blue Carbon management interventions in these vulnerable ecosystems. Supplemental_Information: For more information, see the following field activity: https://cmgds.marine.usgs.gov/fan_info.php?fan=2015-038-FA Time_Period_of_Content: Time_Period_Information: Multiple_Dates/Times: Single_Date/Time: Calendar_Date: 20130719 Single_Date/Time: Calendar_Date: 20130815 Single_Date/Time: Calendar_Date: 20130920 Single_Date/Time: Calendar_Date: 2014 Single_Date/Time: Calendar_Date: 20150521 Currentness_Reference: Ground Condition. These are the dates when the measurements were made and samples were collected. Exact dates for 2014 gas flux measurements were not recorded; they are reported as "Early", "Mid", and "Late" 2014 in reference to the approximate time of year of sample collection. Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -70.50481 East_Bounding_Coordinate: -70.50478 North_Bounding_Coordinate: 41.55656 South_Bounding_Coordinate: 41.55651 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme_Keyword: location Theme_Keyword: elevation Theme_Keyword: oceans Theme_Keyword: environment Theme_Keyword: inlandWaters Theme_Keyword: biota Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: soil chemistry Theme_Keyword: radiometric dating Theme_Keyword: piston coring Theme_Keyword: carbon isotope analysis Theme_Keyword: carbon Theme_Keyword: nitrogen Theme_Keyword: sea-level change Theme_Keyword: sedimentation Theme_Keyword: wetland ecosystems Theme_Keyword: plot sampling Theme_Keyword: wetland functions Theme_Keyword: invasive species Theme_Keyword: coastal processes Theme_Keyword: ecological processes Theme: Theme_Keyword_Thesaurus: National Agricultural Library Thesaurus Theme_Keyword: salt marshes Theme_Keyword: wetland soils Theme_Keyword: wetlands Theme_Keyword: ecological restoration Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: age model Theme_Keyword: Constant Rate of Supply (CRS) model Theme_Keyword: 210-lead Theme_Keyword: 137-cesium Theme_Keyword: accretion rate Theme_Keyword: carbon burial Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:624b1752d34e21f827635bdf Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Sage Lot Pond (616458) Place_Keyword: Mashpee (615624) Place_Keyword: Cape Cod (606914) Place_Keyword: Commonwealth of Massachusetts (606926) Access_Constraints: none Use_Constraints: none Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Meagan J Eagle Contact_Organization: Northeast Region: WOODS HOLE COASTAL AND MARINE SCIENCE Contact_Position: Research Physical Scientist Contact_Address: Address_Type: mailing and physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: US Contact_Voice_Telephone: 508-548-8700 x2280 Contact_Electronic_Mail_Address: meagle@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/624b1752d34e21f827635bdf?name=SLP_Phrag_SplitCore_2015.jpg Browse_Graphic_File_Description: Browse graphic is a photograph of a Phragmites sediment core, collected from Sage Lot Pond, after splitting in the laboratory. Browse_Graphic_File_Type: JPEG Data_Set_Credit: Dr. Elizabeth Watson and Dr. Cathleen Wigand performed pore water sulfide analyses at the Atlantic Ecology Division of the Environmental Protection Agency in Narragansett, RI. Cross_Reference: Citation_Information: Originator: Moseman-Valtierra, Serena Originator: Abdul-Aziz, Omar I. Originator: Tang, Jianwu Originator: Ishtiaq, Khandker S. Originator: Morkeski, Kate Originator: Mora, Jordan Originator: Quinn, Ryan K. Originator: Martin, Rose M. Originator: Egan, Katherine Originator: Brannon, Elizabeth Q. Originator: Carey, Joanna Originator: Kroeger, Kevin D. Publication_Date: 2016 Title: Carbon dioxide fluxes reflect plant zonation and belowground biomass in a coastal marsh Series_Information: Series_Name: Ecosphere Issue_Identification: 7(11), e01560 Publication_Information: Publication_Place: Washington, D.C. Publisher: Ecological Society of America Other_Citation_Details: Data reported in this data release are an extension of data collections in this journal. Online_Linkage: https://doi.org/10.1002/ecs2.1560 Cross_Reference: Citation_Information: Originator: Gonneea, Meagan E. Originator: O'Keefe Suttles, Jennifer A. Originator: Kroeger, Kevin D. Publication_Date: 2018 Title: Collection, analysis, and age-dating of sediment cores from salt marshes on the south shore of Cape Cod, Massachusetts, from 2013 through 2014 Edition: 1.0 Geospatial_Data_Presentation_Form: tabular digital data Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/F7H41QPP Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/F7H41QPP Online_Linkage: https://www.sciencebase.gov/catalog/item/5a748e35e4b00f54eb19f96c Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Radionuclide detection limits are specific to an individual sample and are a function of: 1) the detector efficiency at the energy level of the peak being measured; 2) the branching ratio (expected fraction of decay events at the energy level); 3) the background activity within the sample. Detector efficiency was determined from EPA standard pitchblende ore in the same geometry as the samples. Activities of 7Be, 137Cs, and excess 210Pb (i.e. unsupported) were decay-corrected to time of collection. Suppression of low energy peaks by self-absorption was corrected for according to Cutshall and others, 1983. Peak detection, with respect to background activity, is calculated for each radionuclide in the APTEC peak integration spectroscopy software during sample analysis. Generally, measured radionuclide activity greater than or equal to 0.244 (210Pb), 0.116 (226Ra), 3.79 (7Be), and 0.145 (137Cs) disintegrations per minute per gram were accepted as above detection limit for this dataset. Samples were analyzed for weight percent carbon and nitrogen and the isotopic signature of carbon and nitrogen in organic matter at the University Rhode Island. During analysis, samples were interspersed with several replicates of laboratory reference materials. Any analysis value below detection is given the numerical value of 0. Any attribute that was not measured for a specific sample is left as a blank cell. Cutshall, N.H., Larsen, I.L., and Olsen, C.R., 1983, Direct analysis of 210 Pb in sediment samples—Self-absorption corrections: Nuclear Instruments and Methods in Physics Research, v. 206, issues 1–2, p. 309–312, https://doi.org/10.1016/0167-5087(83)91273-5. Logical_Consistency_Report: Dataset was queried for maximum and minimum values to be sure sample analyses were within expected ranges for the environmental conditions. Data were plotted to look for any obvious outliers that may have been indicative of analytical error. Detection limits are defined in the attribute accuracy section of the metadata. Any analysis value below detection is given the numerical value of 0. Any attribute that was not measured for a specific sample is listed as an empty or blank cell. Each sample was treated in the same manner for each analysis. Completeness_Report: Gas fluxes were not measured 9/20/2013 due to instrument problems, these cells are left blank. In 2014 nitrous oxide was not measured and cells are left blank. In cases in which both methane and carbon dioxide fluxes showed insignificant R2 and P-values, the data were discarded from Data_SLP_Phrag_GHGFluxes.csv, as described in the first process step. Significant fluxes were defined based on R2 values of 0.90 or greater and P-values of 0.05 or less. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Latitude and longitude of core collection locations with a handheld Garmin GPSMAP 76Cx unit in the field at time of sediment core collection. The GPS unit indicated accuracy was within 3 meters. Exact coordinates of the gas flux measurements are not reported; however they are similar in location to those cited in Moseman-Valtierra and others (2016). No formal positional accuracy tests were conducted. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Land surface elevation of the core collection sites were measured by SpectraPrecision (SP80) Real-Time Kinematic (RTK) GPS after core collection. An average elevation for clustered points around the core collection location is reported for the core depth at 0 centimeters. Average vertical accuracy of this method is +/- 5 centimeters. No formal positional accuracy tests were conducted. Lineage: Process_Step: Process_Description: Gas Flux Measurements and Calculations in 2013 and 2014: Three plots were established in both the high marsh and Phragmites australis-invaded zones. Square steel collars (56 cm × 56 cm) sealed the base of the chambers and were preinstalled (at least 1 month prior to first measurements) to a depth of approximately 20 cm. Gas flux measurements were taken within 3 hours of low tide to minimize variability in data brought on by tidal cycling. Gas fluxes were measured during daytime with a transparent chamber to reflect the net result of photosynthesis and respiration in the marsh plots. Carbon dioxide (CO2) and methane (CH4) fluxes were measured by connecting a cavity ring-down spectrometer (Model G2301; Picarro Inc., Santa Clara, California, USA) to a transparent acrylic chamber (60 cm × 60 cm × 60 cm) in a closed loop. nitrous oxide (N2O) fluxes were measured by also connecting a nitrous oxide/carbon monoxide (N2O/CO) gas analyzer (Los Gatos Research, Mountain View, California, USA) to the same chamber. The chamber contained two battery-powered fans to homogenize the air inside, pigtails to prevent pressure accumulation (inner diameter of 0.71 mm), and four ports to connect to inlets and outlets of both analyzers in a closed loop system. All gas fluxes were calculated from linear rates of change in gas concentrations in each chamber over time using the ideal gas law (as detailed in Martin and Moseman-Valtierra 2015). Changes in gas concentrations over time (dC/dt) were analyzed with linear regressions. We define positive fluxes as those in which gas concentrations increased over time within a chamber (representing vertical emission from the marsh surface to the atmosphere), and negative fluxes as those in which concentrations decreased (representing net uptake from the atmosphere to the marsh). Significant fluxes were defined based on R2 values of 0.90 or greater and P-values of 0.05 or less. In cases in which both CH4 and CO2 fluxes showed insignificant R2 and P-values, the data were discarded. Stem Density and Plant Height 2013 and 2014: Native plant community composition and stem density were determined by identifying and counting plants in small quadrats (10 cm × 10 cm for the high marsh) within 1 m of each gas flux collar. Because marsh plant communities are uniform and homogenous within zones, it was not necessary to include flux collars in plant community composition surveys. Heights were measured from 10 randomly selected shoots; the average is reported. Porewater sampling 2013 and 2014: Water was sampled within 1 hour of gas flux measurements from 0 to 10 cm depths using Rhizon samplers (Soil Moisture Co., Goleta, California, USA) and preserved in equal volumes of 1 M zinc acetate and stored frozen (−17 degrees Celsius) for pore water sulfide analyses (following Cline 1969). Soil moisture content was measured (three times per plot in random locations between plant culms) by inserting an EC-5 soil sensor to a depth of 5 cm (Decagon Devices, Pullman, Washington, USA). Soil pH was measured by collecting a surface plug of soil (approximately 5 mL), adding to 10 mL of distilled water in a sterile centrifuge tube, and immediately measuring the pH of the resulting slurry (Orion Star A326 Multiparameter Meter; Thermo Scientific, Pittsburgh, Pennsylvania, USA). In all 2014 dates, soil pH methods were switched (for expediency) to the use of a surface probe pH meter (Ex Stick Instruments, Nashua, New Hampshire, USA). Measurement of pH in a slurry and directly in the sediment were comparable (data not shown). Salinity of water (filtered and squeezed) from surface (0-2 cm) sediments was measured with a handheld refractometer. Dr. Elizabeth Watson and Dr. Cathleen Wigand performed pore water sulfide analyses at the Atlantic Ecology Division of the Environmental Protection Agency in Narragansett, RI following the method of Cline (1969). Martin, R. M., and S. M. Moseman-Valtierra, 2015, Greenhouse gas fluxes vary between Phragmites australis and native vegetation zones in coastal wetlands along a salinity gradient: Wetlands, v. 35, p. 1021–1031, https://doi.org/10.1007/s13157-015-0690-y. Cline, J. D., 1969, Spectrophotometric determination of hydrogen sulfide in natural waters: Limnology and Oceanography,v. 14 p. 454–458, https://doi.org/10.4319/lo.1969.14.3.0454. These processes occurred during 2013 and 2014 with the process date being the most recent occurrence. Process_Date: 2014 Process_Step: Process_Description: A piston coring system was used to collect sediment cores from coastal wetlands on 05/21/2015. The PVC core liner (diameter 11 cm, 1 m in length) was fitted with a gasketed piston that was placed on the sediment surface. The clear, sharpened core liner was pushed down into the marsh subsurface, while the piston was maintained at the marsh surface via tension on the piston. We visually observed the sediment surface to ensure that the soil column did not compact during collection. Once the core reached the desired depth, the core liner and piston were removed from the marsh with a pulley system. Process_Date: 20150521 Process_Step: Process_Description: Sediment cores were immediately returned to the USGS Woods Hole Coastal and Marine Science Center after collection. They were placed in a refrigerator for 1 to 3 days, then split vertically, sectioned at 1 or 2 cm intervals, frozen, and then freeze dried for 7 days until sediment weights did not change further. Dry bulk density was determined as the dry weight of a known volume of sample. Approximately 5 grams of dried sediment sample was blended and homogenized prior to sealing in a jar for a minimum of three weeks and then placed on a planar-type gamma counter for 24 to 48 hours to measure 7Be, 137Cs, 210Pb, and 226Ra at 477, 662, 46.5 and 352 kiloelectronvolts (KeV) energies respectively (Canberra Inc., USA). Detector efficiency was determined from EPA standard pitchblende ore in the same geometry as the samples. Excess 210Pb was calculated as the decay-corrected difference between total 210Pb and supported 210Pb (considered to be equal to 226Ra). Activities of 7Be, 137Cs, and excess 210Pb were decay corrected to time of collection, using their respective half-lives. Suppression of low energy peaks by self-absorption was corrected for according to Cutshall and others, 1983. Gamma spectroscopy detection limits were determined in APTEC software for each sample; refer to the attribute accuracy section of this metadata for further details. Values reported are above this limit, while values below are reported as 0. Core sections not analyzed are reported as blank cells. Sediment ages and accretion rates were calculated with the Constant Rate of Supply (CRS) excess 210Pb age model, a variant on the advection-decay equation (Appleby and Oldfield, 1978; Goldberg, 1963). This model assumes that 210Pb supply to the sediment surface is constant through time, but allows for changing sedimentation rates, in addition to decay, to control the down-core activity of excess 210Pb. The common form of the CRS model, as derived by Appleby and Oldfield (1978), solves for age based on the distribution of excess 210Pb in the sediment record. Prior to application of the age model, excess 210Pb profiles were evaluated to ensure they were sufficiently resolved to apply the CRS model without bias towards ages that are too old or accretion rates that are too low at depth (Binford, 1990). Negative values of excess 210P occur where 226Ra is greater than 210Pb-total. These sections are not included in the age-model calculations. All gamma analyses were ongoing from 2015 and completed in 2018. Appleby, P.G., and Oldfield, F., 1978, The calculation of lead-210 dates assuming a constant rate of supply of unsupported 210Pb to the sediment: Catena, v. 5, issue 1, p. 1–8, https://doi.org/10.1016/S0341-8162(78)80002-2. Binford, M.W., 1990, Calculation and uncertainty analysis of 210 Pb dates for PIRLA project lake sediment cores: Journal of Paleolimnology, v. 3, issue 3, p. 253-267, https://doi.org/10.1007/BF00219461. Cutshall, N.H., Larsen, I.L., and Olsen, C.R., 1983, Direct analysis of 210 Pb in sediment samples—Self-absorption corrections: Nuclear Instruments and Methods in Physics Research, v. 206, issues 1–2, p. 309–312, https://doi.org/10.1016/0167-5087(83)91273-5. Goldberg, E.D., 1963, Geochronology with 210 Pb, in Miller, J.A., convener, Radioactive dating: International Atomic Energy Agency Symposium on Radioactive Dating, Athens, Greece, November 19-23, 1962, [Proceedings], p. 121-131. Process_Date: 2018 Process_Step: Process_Description: A subsample of freeze dried sediment (0.5 g) was ball-milled to a fine powder and analyzed for weight percent carbon and nitrogen and the isotopic signature of carbon and nitrogen in organic matter at the University Rhode Island. During analysis, samples are interspersed with several replicates of laboratory reference material and blanks. Process_Date: 2016 Process_Step: Process_Description: Raw data were entered into an Excel spreadsheet where all calculations were completed. The Excel spreadsheet was exported as a CSV file from Excel for Mac version 15.33. The CSV file was processed in MATLAB to round calculated values to appropriate place values and again exported as a comma separated comma separated text file (*.csv). Note that all calculations were performed prior to rounding and truncating values reported in this data release. Process_Date: 2022 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Meagan J Eagle Contact_Organization: Northeast Region: WOODS HOLE COASTAL AND MARINE SCIENCE CENTER Contact_Position: Research Physical Scientist Contact_Address: Address_Type: mailing and physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: US Contact_Voice_Telephone: 508-548-8700 x2280 Contact_Electronic_Mail_Address: meagle@usgs.gov Process_Step: Process_Description: Fixed a typo in the DOI link (20230324). Process_Date: 20230324 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: VeeAnn A. Cross Contact_Position: Marine Geologist Contact_Address: Address_Type: Mailing and Physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-548-8700 x2251 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: vatnipp@usgs.gov Spatial_Data_Organization_Information: Indirect_Spatial_Reference: Geographic Names Information System (GNIS) placenames are included as keywords to give the general location of core collections. The entity contains attributes with specific latitude and longitude of each core collection; several attributes are also included to describe the locations of core collections and gas flux measurement (nearest body of water and vegetation type). Refer to the entity and attribute definitions for "site_name", "veg_type", and "core_ID" for details. Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 1.0E-5 Longitude_Resolution: 1.0E-5 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257222101 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988 Altitude_Resolution: 0.01 Altitude_Distance_Units: meters Altitude_Encoding_Method: Attribute values Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Data_SLP_Phrag_Cores.csv Entity_Type_Definition: Comma separated text file with soil core data collected from Phragmites vegetated sites within Sage Lot Pond, a tidal wetland within the Waquoit Bay National Estuarine Research Reserve. The file includes latitude and longitude of core collection, calculated values of soil dry bulk density, mass accumulation rates, vertical accretion rates, and carbon burial rates. Also included are the data required for those calculations: radionuclide data, soil carbon and nitrogen content. The dataset includes 92 records. Entity_Type_Definition_Source: Producer-defined Attribute: Attribute_Label: site_name Attribute_Definition: A text identifier for the general location of the study site. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Sage Lot Pond Enumerated_Domain_Value_Definition: A data point from a sediment core collected from Sage Lot Pond, a tidal wetland within the Waquoit Bay National Estuarine Research Reserve, Mashpee, MA. Enumerated_Domain_Value_Definition_Source: Producer-defined Attribute: Attribute_Label: veg_type Attribute_Definition: A text identifier indicating the vegetation type that dominates the sediment core collection site. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Phragmites Enumerated_Domain_Value_Definition: Data point collected from a study site that is dominated by Phragmites australis. Enumerated_Domain_Value_Definition_Source: Producer-defined Attribute: Attribute_Label: core_ID Attribute_Definition: Abbreviated alphabetical identification code of each core to indicate: 1) the study site from which it was collected using a three-letter abbreviation, 2) a numeric qualifier to indicate the order of core collection over time/replicate core number (either 1 or 2), and 3) the vegetation type for the core collection site indicated by an abbreviation of the scientific name. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SLP1Phrag Enumerated_Domain_Value_Definition: Sage Lot Pond, core 1, Phragmites Enumerated_Domain_Value_Definition_Source: Producer-defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: SLP2Phrag Enumerated_Domain_Value_Definition: Sage Lot Pond, core 2, Phragmites Enumerated_Domain_Value_Definition_Source: Producer-defined Attribute: Attribute_Label: date_collected Attribute_Definition: A numeric identifier of the date the core was collected in the format of month/day/year. Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 05/21/15 Range_Domain_Maximum: 05/21/15 Attribute_Units_of_Measure: mm/dd/yyyy Attribute: Attribute_Label: latitude Attribute_Definition: Latitude decimal degrees north, NAD83 Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 41.55651 Range_Domain_Maximum: 41.55656 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: longitude Attribute_Definition: Longitude decimal degrees west, NAD83. The negative value indicates a location in the western hemisphere. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -70.50481 Range_Domain_Maximum: -70.50478 Attribute_Units_of_Measure: decimal degrees Attribute: Attribute_Label: depth_mid Attribute_Definition: A numeric identifier of the interval mid-point depth below the sediment interface in centimeters. Note that depth = 0 cm is given as a reference point in order to include the land surface elevation within the dataset. Sediment core analyses are not reported for this sample depth because it is not a sampled horizon within a collected core. The minimum interval mid-point for each core is 0.5 cm. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 69.5 Attribute_Units_of_Measure: centimeters Attribute: Attribute_Label: elevation Attribute_Definition: A numeric identifier of interval mid-point elevation relative to NAVD88 datum in centimeters. Calculated by subtracting the mid-interval sample depth from the NAVD88 elevation of the core location reported as depth = 0 cm within the dataset for each core. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -47.3 Range_Domain_Maximum: 23.1 Attribute_Units_of_Measure: centimeters Attribute: Attribute_Label: DBD Attribute_Definition: Dry Bulk Density: A numeric identifier of the sediment dry bulk density in grams per cubic centimeter (g/cm3). Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.0406 Range_Domain_Maximum: 0.3368 Attribute_Units_of_Measure: grams per cubic centimeter Attribute: Attribute_Label: 210Pb Attribute_Definition: A numeric identifier of the sediment total lead-210 activity in decays per minute per gram (dpm/g). Measured at 46.5 kiloelectron volts (KeV) on a planar gamma counter. Blank/empty cells indicate the measurement was not done. Minimum detection limit 0.244 Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.2443 Range_Domain_Maximum: 32.0775 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: 210Pb_e Attribute_Definition: A numeric identifier of the measurement error in sediment total lead-210 activity in decays per minute per gram (dpm/g). Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.1084 Range_Domain_Maximum: 1.6266 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: 226Ra Attribute_Definition: A numeric identifier of the sediment total radium-226 activity in decays per minute per gram (dpm/g). Measured at 352 kiloelectron volts (KeV) on a planar gamma counter. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection (0.116 dmp/g). Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.1168 Range_Domain_Maximum: 8.7832 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: 226Ra_e Attribute_Definition: A numeric identifier of the measurement error in sediment total radium-226 activity in decays per minute per gram (dpm/g). Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.0319 Range_Domain_Maximum: 0.5850 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: 210Pbex Attribute_Definition: A numeric identifier of the sediment excess lead-210 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Calculated as the difference between total lead-210 and total radium-226 activities. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -0.7255 Range_Domain_Maximum: 31.7495 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: 210Pbex_e Attribute_Definition: A numeric identifier of the propagated measurement error in sediment excess lead-210 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.1155 Range_Domain_Maximum: 1.6720 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: 137Cs Attribute_Definition: A numeric identifier of the sediment total cesium-137 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Measured at 662 kiloelectron volts (KeV) on a planar gamma counter. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection (0.145 dpm/g). Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.1451 Range_Domain_Maximum: 1.0691 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: 137Cs_e Attribute_Definition: A numeric identifier of the measurement error in sediment total cesium-137 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.0356 Range_Domain_Maximum: 0.1438 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: 7Be Attribute_Definition: A numeric identifier of the measurement error in sediment total beryllium-7 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Measured at 477 kiloelectron volts (KeV) on a planar gamma counter. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection (3.79 dpm/g). Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 3.7955 Range_Domain_Maximum: 5.9081 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: 7Be_e Attribute_Definition: A numeric identifier of the measurement error in sediment total beryllium-7 activity in decays per minute per gram (dpm/g), decay-corrected to date of core collection. Blank/empty cells indicate the measurement was not done. The value 0.00 is given to analyzed samples found to be below detection. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.9429 Range_Domain_Maximum: 1.4248 Attribute_Units_of_Measure: decays per minute per gram Attribute: Attribute_Label: wtC Attribute_Definition: Total amount of carbon by weight percent in soil. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 22.4 Range_Domain_Maximum: 46.58 Attribute_Units_of_Measure: unitless Attribute: Attribute_Label: wtN Attribute_Definition: Total amount of nitrogen by weight percent in soil. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.98 Range_Domain_Maximum: 2.19 Attribute_Units_of_Measure: unitless Attribute: Attribute_Label: 13C Attribute_Definition: The carbon isotopic signature of the soil sample relative to Pee Dee Belemnite (PDB) standard. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -28.75 Range_Domain_Maximum: -21.55 Attribute_Units_of_Measure: parts per thousand OR per mil Attribute: Attribute_Label: 15N Attribute_Definition: The nitrogen isotopic signature of the soil sample relative to air. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.04 Range_Domain_Maximum: 2.99 Attribute_Units_of_Measure: parts per thousand OR per mil Attribute: Attribute_Label: Age Attribute_Definition: A numeric identifier for the age in years from the collection date of the core interval based on the Constant Rate of Supply excess lead-210 age model. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 133.5 Attribute_Units_of_Measure: years Attribute: Attribute_Label: Age_e Attribute_Definition: A numeric identifier for the age model uncertainty in years of the core interval based on the Constant Rate of Supply excess lead-210 age model. Error is propagated through the model. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 42.2 Attribute_Units_of_Measure: years Attribute: Attribute_Label: VAR Attribute_Definition: Vertical Accretion Rate: A numeric identifier for the vertical accretion rate of the sediment in millimeters per year (mm/y). Calculated as the difference in interval midpoint divided by the difference in ages of those adjacent sediment intervals. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1.4 Range_Domain_Maximum: 10.8 Attribute_Units_of_Measure: millimeters per year Attribute: Attribute_Label: MAR Attribute_Definition: Mass Accumulation Rate: A numeric identifier for the mass accumulation rate of the sediment in grams per square meter per year (g/m2/y). Calculated by multiplying dry bulk density times vertical accretion rate. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 256 Range_Domain_Maximum: 1377 Attribute_Units_of_Measure: grams sediment per square meter per year Attribute: Attribute_Label: CAR Attribute_Definition: Carbon Accumulation Rate: A numeric identifier for the carbon mass accumulation rate of the sediment in grams of carbon per square meter per year (gC/m2/y). Calculated by multiplying the average mass accumulations rate for the combined depth interval of the elemental sample times weight percent carbon. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 65 Range_Domain_Maximum: 213 Attribute_Units_of_Measure: grams carbon per square meter per year Attribute: Attribute_Label: Year Attribute_Definition: The year corresponding to the soil horizon based on the Constant Rate of Supply excess lead-210 age model. Calculated as collection date minus age of sediment at each depth interval. Attribute_Definition_Source: Producer-defined. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1882 Range_Domain_Maximum: 2015.5 Attribute_Units_of_Measure: calendar year Detailed_Description: Entity_Type: Entity_Type_Label: SLP_Phragmities_GHGFluxes.csv Entity_Type_Definition: Comma separated text file with measurements of carbon fluxes (carbon dioxide and methane) collected using static chambers at sites dominated by 2 different salt marsh vegetation types across a seasonal time scale at Sage Lot Pond in Mashpee, MA from July 2013 through November 2014. Environmental and biologic metrics that could inform carbon exchange, (including stem density, plant height, and porewater pH/ORP, salinity, sulfide, methane, and soil moisture) were also collected to support data interpretation. The dataset contains 36 records. Entity_Type_Definition_Source: Producer-defined Attribute: Attribute_Label: site_name Attribute_Definition: A text identifier for the general location of the study site. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Sage Lot Pond Enumerated_Domain_Value_Definition: A data point from a site location in Sage Lot Pond, a tidal wetland within the Waquoit Bay National Estuarine Research Reserve, Mashpee, MA. Enumerated_Domain_Value_Definition_Source: Producer-defined Attribute: Attribute_Label: date Attribute_Definition: An identifier of the date the GHG fluxes were measured and porewater samples were collected. Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 07/19/2013 Range_Domain_Maximum: 09/20/2013 Attribute_Units_of_Measure: month/day/year Attribute_Domain_Values: Unrepresentable_Domain: In 2014, exact dates of field measurements were not recorded. Measurements were made to capture a seasonal time period. Approximate time of year is reported as "Early 2014", "Mid 2014", or "Late 2014". Attribute: Attribute_Label: veg_type Attribute_Definition: A text identifier indicating the vegetation type that dominates the location of the GHG measurement and porewater collection site. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Phragmites australis Enumerated_Domain_Value_Definition: Data point collected from a location within the study site that is dominated by Phragmites australis. Enumerated_Domain_Value_Definition_Source: Producer-defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Distichlis spicata Enumerated_Domain_Value_Definition: Data point collected from a location within the study site that is dominated by Distichlis spicata. Enumerated_Domain_Value_Definition_Source: Producer-defined Attribute: Attribute_Label: chamber_rep Attribute_Definition: Identifier of the chamber replicate at each sampling location. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 3 Attribute_Units_of_Measure: numerical order Attribute: Attribute_Label: stem_height Attribute_Definition: Mean height in centimeters of 10 randomly selected shoots within the quadrat; see process step for measurement description. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 24 Range_Domain_Maximum: 169 Attribute_Units_of_Measure: cm Attribute: Attribute_Label: stem_density Attribute_Definition: Number of individual plants per square meter; see process step for measurement description. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 9 Range_Domain_Maximum: 133 Attribute_Units_of_Measure: stems per square meter Attribute: Attribute_Label: sal_porewater Attribute_Definition: A numeric data value of measured porewater salinity in practical salinity units (PSU); see process steps for measurement description. Blank/empty cells indicate the measurement was not done Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 20 Range_Domain_Maximum: 30 Attribute_Units_of_Measure: PSU Attribute: Attribute_Label: soil_moisture Attribute_Definition: Mean of three soil moisture measurements; see process steps for measurement description. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 55.9 Range_Domain_Maximum: 69.7 Attribute_Units_of_Measure: percent Attribute: Attribute_Label: pH_porewater Attribute_Definition: A numeric data value of measured porewater pH; see process steps for measurement description. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 6.79 Range_Domain_Maximum: 7.66 Attribute_Units_of_Measure: pH units Attribute: Attribute_Label: ORP_porewater Attribute_Definition: A numeric data value measured porewater Oxidation Reduction Potential; see process steps for measurement description. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -352.5 Range_Domain_Maximum: 148 Attribute_Units_of_Measure: mV Attribute: Attribute_Label: sulfide_porewater Attribute_Definition: A numeric data value of measured porewater sulfide; see process steps for field collection and laboratory analysis descriptions. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 1334.79 Attribute_Units_of_Measure: micromol per liter Attribute: Attribute_Label: CH4_porewater Attribute_Definition: A numeric data value of measured porewater methane; see process steps for field collection and laboratory analysis descriptions. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 33.40 Attribute_Units_of_Measure: micromol per liter Attribute: Attribute_Label: CO2_flux Attribute_Definition: Flux of carbon dioxide calculated from the slope of CO2 concentration change in micromoles of CO2 per square meter per second. Positive values indicate a flux of CO2 out of the ecosystem into the atmosphere and negative values indicate a flux out of the atmosphere into the ecosystem. See process steps for measurement description. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -18.02 Range_Domain_Maximum: 6.73 Attribute_Units_of_Measure: micromol CO2 per square meter per second Attribute: Attribute_Label: CH4_flux Attribute_Definition: Flux of methane calculated from the slope of CH4 concentration change in nanomoles of CH4 per square meter per second. Positive values indicate a flux of methane out of the ecosystem into the atmosphere and negative values indicate a flux out of the atmosphere into the ecosystem. See process steps for measurement description. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.00 Range_Domain_Maximum: 33.40 Attribute_Units_of_Measure: nanomol CH4 per square meter per second Attribute: Attribute_Label: N2O_flux Attribute_Definition: Flux of nitrous oxide calculated from the slope of N2O concentration change in nanomoles of CH4 per square meter per second. Positive values indicate a flux of methane out of the ecosystem into the atmosphere and negative values indicate a flux out of the atmosphere into the ecosystem. See process steps for measurement description. Blank/empty cells indicate the measurement was not done. Attribute_Definition_Source: Producer-defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -1.42 Range_Domain_Maximum: 0.36 Attribute_Units_of_Measure: nanomol N2O per square meter per second Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: ScienceBase Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing and physical Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Country: US Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: The dataset contains two CSV files containing the data (Data_SLP_Phrag_Cores.csv; Data_SLP_Phrag_GHGFluxes.csv), the browse graphic (SLP_Phrag_SplitCore_2015.jpg), and the FGDC CSDGM metadata in XML format. Distribution_Liability: Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: CSV Format_Version_Number: Microsoft Excel Office 365 Format_Information_Content: The data release includes 2 comma separated files, a browse graphic, and the FGDC CSDGM metadata. Transfer_Size: 1 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/624b1752d34e21f827635bdf Network_Resource_Name: https://www.sciencebase.gov/catalog/item/624b1752d34e21f827635bdf Network_Resource_Name: https://doi.org/10.5066/10.5066/P9JM751N Access_Instructions: Access instructions: The first link downloads all the files on the landing page, the second link is to the datasets' landing page, and the third link is the DOI link of the data release which is the landing page as the second link. Fees: None Technical_Prerequisites: The zip file resulting from the first network resource link contains data in CSV format. The user must have software capable of uncompressing the zip file and reading the data formats. Metadata_Reference_Information: Metadata_Date: 20230324 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Jennifer A. O'Keefe Suttles Contact_Organization: Northeast Region: WOODS HOLE COASTAL AND MARINE SCIENCE CENTER Contact_Position: Chemist Contact_Address: Address_Type: mailing and physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Country: United States Contact_Voice_Telephone: 508-548-8700 x2385 Contact_Electronic_Mail_Address: whsc_data_contact@usgs.gov Contact_Instructions: The metadata contact email address is a generic address in the event the person is not longer with USGS. Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998