Toggle navigation Project name Home Temporal coverage Geographic coverage Data tables Custom units Other entities Accuracy and Precision of Tidal Wetland Soil Carbon Mapping in the Conterminous United States: Public Soil Carbon Data Release Version 1 2018 View Data Files Data table(s) 5 Other entity(ies) 0 Abstract Tidal wetlands produce long-term soil organic carbon (C) stocks. Thus for carbon accounting purposes, we need accurate and precise information on the magnitude and spatial distribution of those stocks. We assembled and analyzed an unprecedented soil core dataset, and tested three strategies for mapping carbon stocks: applying the average value from the synthesis to mapped tidal wetlands, applying models fit using empirical data and applied using soil, vegetation and salinity maps, and relying on independently generated soil carbon maps. Soil carbon stocks were far lower on average and varied less spatially and with depth than stocks calculated from available soils maps. Further, variation in carbon density was not well-predicted based on climate, salinity, vegetation, or soil classes. Instead, the assembled dataset showed that carbon density across the conterminous united states (CONUS) was normally distributed, with a predictable range of observations. We identified the simplest strategy, applying mean carbon density (27.0 kgC m^-3), as the best performing strategy, and conservatively estimated that the top meter of CONUS tidal wetland soil contains 0.72 petagrams C. This strategy could provide standardization in CONUS tidal carbon accounting until such a time as modeling and mapping advancements can quantitatively improve accuracy and precision. This data release includes the soil carbon data currently considered public by the data submittors. Additional detail can be found in the publication. Holmquist JR et al. (2018). Accuracy and Precision of Tidal Wetlands Soil Carbon Mapping in the Conterminous United States. Scientific Reports. DOI:10.1038/s41598-018-26948-7. Funding Sources: NASA Carbon Monitoring System [NNH14AY67I], National Science Foundation [DEB-1655622], Smithsonian Institution, USGS Landcarbon Program. Metadata Provider Author list Creators James Holmquist HolmquistJ@si.edu Associated parties James Holmquist HolmquistJ@si.edu Lisamarie Windham-Myers lwindham-myers@usgs.gov Norman Bliss bliss@usgs.gov Stephen Crooks steve.crooks.bc@gmail.com James Morris morris@inlet.geol.sc.edu J Megonigal MegonigalP@si.edu Tiffany Troxler troxlert@fiu.edu Donald Weller wellerd@si.edu John Callaway callaway@usfca.edu Judith Drexler jdrexler@usgs.gov Matthew Ferner mferner@sfsu.edu Meagan Gonneea mgonneea@usgs.gov Kevin Kroeger kkroeger@usgs.gov Lisa Schile-Beers lmschile@gmail.com Isa Woo iwoo@usgs.gov Kevin Buffington kbuffington@usgs.gov Brandon Boyd Brandon.M.Boyd@erdc.dren.mil Joshua Breithaupt jlbreith@mail.usf.edu Lauren Brown lnbrown@ucla.edu Nicole Dix Nikki.Dix@dep.state.fl.us Lyndie Hice lhice-dunton@ene.com Benjamin Horton bphorton@marine.rutgers.edu Glen MacDonald macdonal@geog.ucla.edu Ryan Moyer Ryan.Moyer@myfwc.com William Reay wreay@vims.edu Timothy Shaw tshaw@marine.rutgers.edu Erik Smith erik@belle.baruch.sc.edu Joseph Smoak smoak@mail.usf.edu Christopher Sommerfield cs@udel.edu Karen Thorne KThorne@USGS.gov David Velinsky djv23@drexel.edu Elizabeth Watson elizabeth.b.watson@gmail.com Kristen Grimes kristin.wilson@uvi.edu Mark Woodrey msw103@msstate.edu Keywords tidal wetland soil carbon blue carbon coastal wetland salt marsh mangrove tidal freshwater wetland tidal freshwater forest soil mapping soil carbon mapping map accuracy map precision data synthesis Temporal coverage Start date End date 1990 2017 Geographic coverage Taxonomic coverage Rank name Value Species Agrostis spp. Species Alternanthera philoxeroides Species Amaranthus cannabinus Species Ambrosia trifida Species Arrow arum Species Athyrium filix-femina Species Avicennia germinans Species Baccharis halimifolia Species Batis maritima Species Bidens laevis Species Bolboschoenus maritimus Species Carex lyngbyei Species Cornus sericea Species Cuscuta salina Species Distichlis spicata Species Echinochloa spp. Species Eleocharis palustris Species Eleocharis spp. Species Frankenia salina Species Gaultheria shallon Species Grindelia stricta Species Hibiscus spp. Species Impatiens capensis Species Iva frutescens Species Jaumea carnosa Species Juncus balticus Species Juncus roemerianus Species Lonicera involucrata Species Ludwigia spp. Species Lysichiton americanus Species Myrica gale Species Nuphar advena Species Nyssa aquatica Species Oenanthe sarmentosa Species Panicum hemitomon Species Paspalum vaginatum Species Peltandra virginica Species Phalaris arundinacea Species Phragmites australis Species Picea sitchensis Species Polygonum arifolium Species Polygonum punctatum Species Polygonum sagittatum Species Polygonum spp. Species Rhizophora mangle Species Rosa californica Species Rosa nutkana Species Rosa pisocarpa Species Rubus spectabilis Species Rubus ursinus Species Sagittaria latifolia Species Salix lasiolepis Species Sagittaria lancifolia Species Salicornia pacifica Species Salicornia virginica Species Scirpus acutus Species Scirpus americanus Species Schoenoplectus californicus Species Schoenoplectus tabernaemontani Species Spartina alterniflora Species Spartina cynosuroides Species Spiraea douglasii Species Spartina foliosa Species Spartina patens Species Spartina spp. Species Taxodium distichum Species Triglochin maritima Species Trapa natis Species Typa angustifolia Species Typa domingensis Species Typha latifolia Species Typha spp. Species Zizania aquatica Species Zizaniopsis milaceae Data tables V1_Holmquist_2018_methods_data , Methods information for each study (Version 1) Physical: V1_Holmquist_2018_methods_data.csv attribute name definition format, unit or codes study_id Unique identifier for the study made up of the first author's family name, as well as the second author's or 'et al.' if more than three, then publication year spearated by underscores. See worksCited.bib for more detail. publication_type Code indicating the type of publication the study originates from. dissertation = Source was a Ph.D. dissertation. government report = Source was a government report. peer reviewed publication = Source was a peer reviewed publication. private sector report = Source was a private sector report. publically available dataset = Source was a publically available dataset. thesis = Source was a master's thesis. n Number of cores per study. number coring_method Code indicating what type of device was used to collect soil depth profiles. gouge auger = A half cylinder coring device in which the coring section is open, not sealed off by a fin. hargas corer = A large diameter (>10 cm) coring device consisting of a tube, piston, and a cutting head. mcauley corer = A half cylinder coring device with the coring section sealed off by a fin attached to a rotating pivot point. mccaffrey peat cutter = U-shaped blade that extracts a core by cutting down through peat. none specified = No coring device was specified. other shallow corer = Any other type of coring device typically taking cores shallower than 30 centimeters. piston corer = A device that extrudes core into tube upward with a plunger. push core = Any number of coring types involving driving a tube into the sediment to recover a core. pvc and hammer = PVC pipe was driven into the sediment with a hammer to recover a core. russian corer = A half cylinder coring device with the coring section sealed off by a fin attached to a rotating pivot point. vibracore = A technique involving collecting a core by sinking a continuous pipe into sediment attaching a source of vibration, then recovering using a winch and pulley. roots_flag Any notable comments on how the authors either included or excluded live roots from carbon assesments. roots and rhizomes included = Roots and rhizomes were included in dry bulk density and or organic matter and carbon measurements. roots seperated using floation = Roots and rhizomes were separated from soil using floatation before dry bulk density and or organic matter and carbon measurements. compaction_flag Any notable comments on how the authors qualified or quantified compaction of the core. < 10-20% = Compaction was less than 10 to 20% of the core depth. corer limits compaction = Authors specified that the coring device's design minimized compaction. no obvious compaction = Authors observed no obvious compaction. dry_bulk_density_temperature Temperature at which samples were dried to measure dry bulk density. celsius dry_bulk_density_time Time over which samples were dried to measure dry bulk density. hour dry_bulk_density_flag Any notable comments on how the authors quantified dry bulk density. air dried to constant mass = Methodology specified that samples were air dried to a constant mass. duplicate measurements = Methodology specified that the reported values are the averages of duplicated measurements. estimated from loss on ignition and particle densities of mineral and organic solids = Bulk density was not measured, but was modeled from loss on ignition and assumptions about the particle densities of organic and inorganic matter. freeze dried = Bulk density was measured on freeze dried samples. no details = No additional details regarding bulk density methodology were provided. removed non structural water = Bulk density methodology did not specify drying temperature or length, only that non-strucural water was removed. time approximate = Bulk density time recorded herin is an approximate estimate. time not specified = Bulk density time was not specified. to constant mass = Bulk density methodology did not specify drying temperature or length, only that samples were dried to a constant mass. loss_on_ignition_temperature Temperature at which samples were combusted to estimate fraction organic matter. celsius loss_on_ignition_time Time over which samples were combusted to estimate fraction organic matter. hour loss_on_ignition_flag Any notable comments on how the authors estimated organic matter fraction using loss on ignition. duplicate measurements = Methodology specified that the reported values are the averages of duplicated measurements. ground and sieved = Methodology specified that the samples were ground and seived before loss on ignition. no details = No additional details regarding loss on ignition methodology were provided. time not specified = No additional details regarding loss on ignition duration were provided. carbon_measured_or_modeled Code indicating whether fraction carbon was measured or estimated as a function of organic matter. measured = Fraction carbon was measured as opposed to modeled. modeled = Fraction carbon was modeled as opposed to measured. carbonates_removed Whether or not carbonates were removed prior to calculating fraction organic carbon. FALSE = Carbonates were not removed before measuring organic carbon. TRUE = Carbonates were removed before measuring organic carbon. carbonate_removal_method The method used to remove carbonates prior to measuring fraction carbon. 1N H3PO4 = I normal phosphoric acid was used to remove carbonates. direct acid treatment = Carbonates were removed using direct application of dilute acid. HCl fumigation = Carbonates were removed by fumigating with concentrated hydrochloric acid. low carbonate soil = Organic carbon fraction were measured without removing carbonates becasuse assuming carbonate content of the soil type was minimal. none specified = Carbonate removal methodology was not specified. fraction_carbon_flag Any notable comments on how the authors measured fraction carbon. extrapolated from subset of samples = A regression model fit using a subset of measurements was used to predict fraction carbon as a funciton of fraction organic matter. fumigated to remove microbeal biomass = Authors report removing microbeal biomass with acid fumigation. no details = No additional detals were provided regarding fraction carbon methodologies. replicate samples = Methodology specified that the reported values are the averages of duplicated measurements. V1_Holmquist_2018_core_data , Soil core sub-site information (Version 1) Physical: V1_Holmquist_2018_core_data.csv attribute name definition format, unit or codes study_id Unique identifier for the study made up of the first author's family name, as well as the second author's or 'et al.' if more than three, then publication year spearated by underscores. See worksCited.bib for more detail. core_id Author defined unique identifier assiged to a core. core_latitude Positional latitude of the core decimal degrees (World Geodetic System 1988 [WGS1988]). degree core_longitude Positional longitude of the core decimal degrees (World Geodetic System 1988 [WGS1988]). degree position_code Code assigned to rank the quality of latitude and longitude information extracted from the source. a = Latitude and longitude were likely from a high quality source. a1 = Latitude and longitude from handheld GPS or better. a2 = Latitude and longitude were likely high quality but may refer to a general area rather than individual core location. b = Latitude and longitude represented coarse and general site coordinates. c = Latitude and longitude were extracted from a map figure. c1 = Latitude and longitude were extracted from a relatively high quality map figure. c2 = Latitude and longitude were extracted from a relatively low quality map figure. core_elevation Elevation of the coring site relative to North American Vertical Datum 1988 (NAVD88). meter salinity_code Code indicating broad salinity of the coring site. Bra = Brackish (0.5 to 30 parts per thousand salinity). Bra Fre = Brackish to Fresh (< 30 parts per thousand salinity). Bra Sal = Brackis to Saline (> 0.5 parts per thousand salinity). Del = Deltaic (Recieves primariy freshwater input from river discharge). Est = Estuarine (5 to 35 parts per thousand salinity). Fre = Freshwater (< 0.5 parts per thousand salinity). Int = Intermediate salinity (Salinity is somewhere between fully fresh and fully saline). Mes = Mesohaline (5 to 18 parts per thousand salinity). Oli = Oligohaline (0.5 to 5 parts per thousand salinity). Pol = Polyhaline (18 to 30 parts per thousand salinity). Riv = Riverine (Salinity is dominated by freswater river discharge). Sal = Saline (30 to 50 parts per thousand salinity). vegetation_code Code indicating broad vegetation categories at the coring site. EM = Dominated by emergent non woody vasular plant biomass. FO = Dominated by forested biomass. FO/SS = Dominated by forested to scrub/shrub biomass. inundation_class Code based on userent indicating how often the coring location is inundated. High = Core was collected from the high zone of the tidal frame. Hollow = Core was collected from a low elevation hollow zone. Hummock = Core was collected from a high elevation hummock zone. Levee = Core was collected from a high elevation built up edge of a marsh. Low = Core was collected from the low zone of the tidal frame. Mid = Core was collected from the mid zone of the tidal frame. Plain = Core was collected from a low elevation interior of a marsh. River's Edge = Core was collected from a river's edge. core_length_flag Indicated whether or not the coring team believes they recovered a full sediment profile, down to bedrock, or other non-marsh interface. core depth limited by length of corer = The total depth of the core was limited by the length of the coring device. core depth represents deposit depth = Authors report that the depth of the core represents the depth of the wetland soil deposit. not specified = Authors did not specify whether or not the depth of the core represents the depth of the wetland soil deposit. V1_Holmquist_2018_depth_series_data , Soil core depth series information (Version 1) Physical: V1_Holmquist_2018_depth_series_data.csv attribute name definition format, unit or codes study_id Unique identifier for the study made up of the first author's family name, as well as the second author's or 'et al.' if more than three, then publication year spearated by underscores. See worksCited.bib for more detail. core_id Author defined unique identifier assiged to a core. depth_min Minimum depth of a sampling increment. centimeter depth_max Maximum depth of a sampling increment. centimeter dry_bulk_density Dry mass per unit volume of a soil sample. gramsPerCubicCentimeter fraction_organic_matter Mass of organic matter relative to sample dry mass. dimensionless fraction_carbon Mass of carbon relative to sample dry mass. dimensionless fraction_carbon_type Code assigned to specify the type of measurement fraction_carbon represents. fraction_organic_carbon = Author specified that fraction carbon measurements were of organic carbon. fraction_total_carbon = Author specified that fraction carbon measurements were of total carbon. V1_Holmquist_2018_species_data , Dominant species present at core locations (Version 1) Physical: V1_Holmquist_2018_species_data.csv attribute name definition format, unit or codes study_id Unique identifier for the study made up of the first author's family name, as well as the second author's or 'et al.' if more than three, then publication year spearated by underscores. See worksCited.bib for more detail. core_id Author defined unique identifier assiged to a core. species_code Code associated with a species or a vegetation assembelage. Mix = Mix of multiple species. Swamp = Louisiana freshwater forested wetlands. UnVeg = Unvegetated. AgSp = Agrostis spp. AlPh = Alternanthera philoxeroides. AmCa = Amaranthus cannabinus. AmTr = Ambrosia trifida. ArAr = Arrow arum. AtFi = Athyrium filix-femina. AvGe = Avicennia germinans. BaHa = Baccharis halimifolia. BaMa = Batis maritima. BiLa = Bidens laevis. BoMa = Bolboschoenus maritimus. CaLy = Carex lyngbyei. CoSe = Cornus sericea. CuSa = Cuscuta salina. DiSp = Distichlis spicata. EcSpp = Echinochloa spp. ElPa = Eleocharis palustris. ElSpp = Eleocharis spp. FrSa = Frankenia salina. GaSh = Gaultheria shallon. GrSt = Grindelia stricta. HiSpp = Hibiscus spp. ImCa = Impatiens capensis. IvFr = Iva frutescens. JaCa = Jaumea carnosa. JuBa = Juncus balticus. JuRo = Juncus roemerianus. LoIn = Lonicera involucrata. LuSpp = Ludwigia spp. LyAm = Lysichiton americanus. MyGa = Myrica gale. NuAd = Nuphar advena. NyAq = Nyssa aquatica. OeSa = Oenanthe sarmentosa. PaHe = Panicum hemitomon. PaVa = Paspalum vaginatum. PeVi = Peltandra virginica. PhAr = Phalaris arundinacea. PhAu = Phragmites australis. PiSi = Picea sitchensis. PoAr = Polygonum arifolium. PoPu = Polygonum punctatum. PoSa = Polygonum sagittatum. PoSpp = Polygonum spp. RiMa = Rhizophora mangle. RoCa = Rosa californica. RoNu = Rosa nutkana. RoPi = Rosa pisocarpa. RuSp = Rubus spectabilis. RuUr = Rubus ursinus. SaLa = Sagittaria latifolia. SaLas = Salix lasiolepis. SaLan = Sagittaria lancifolia. SaPa = Salicornia pacifica. SaVi = Salicornia virginica. ScAc = Scirpus acutus. ScAm = Scirpus americanus. ScCa = Schoenoplectus californicus. ScTa = Schoenoplectus tabernaemontani. SpAl = Spartina alterniflora. SpCy = Spartina cynosuroides. SpDo = Spiraea douglasii. SpFo = Spartina foliosa. SpPa = Spartina patens. SpSpp = Spartina spp. TaDi = Taxodium distichum. TrMa = Triglochin maritima. TrNa = Trapa natis. TyAg = Typa angustifolia. TyDo = Typa domingensis. TyLa = Typha latifolia. TySpp = Typha spp. ZiAq = Zizania aquatica. ZiMi = Zizaniopsis milaceae. V1_Holmquist_2018_impact_data , List of anthropogenic impacts at core locations (Version 1) Physical: V1_Holmquist_2018_impact_data.csv attribute name definition format, unit or codes study_id Unique identifier for the study made up of the first author's family name, as well as the second author's or 'et al.' if more than three, then publication year spearated by underscores. See worksCited.bib for more detail. core_id Author defined unique identifier assiged to a core. impact_code Code indicating any major anthropogenic impacts historically and currently affecting the coring location. Can = Canalled. Dik = Diked. Dit = Ditched. Eut = Eutrophic. Imp = Impounded. Man = Managed. Nat = Natural. Res = Restoring. SalImp = Salt impacted. Custom units unit name parent SI unit unit type description Other entities Intellectual Rights This dataset is listed under a Creative Commons BY 4.0 and can be used with attribution. https://creativecommons.org/licenses/by/4.0/. Users should take care to credit both this synthesis effort and all primary sources listed herein. Development supported by created with emldown