Tidal wetlands play an important role with respect to climate change because of both their sensitivity to sea-level rise and their ability to sequester carbon dioxide from the atmosphere. Policy-based interest in carbon sequestration has increased recently, and wetland restoration projects have potential for carbon credits through soil carbon sequestration. We measured sediment accretion, mineral and organic matter accumulation, and carbon sequestration rates using 137Cs and 210Pb downcore distributions at six natural tidal wetlands in the San Francisco Bay Estuary. The accretion rates were, in general, 0.2 - 0.5 cm per year -1 indicating that local wetlands are keeping pace with recent rates of sea-level rise. Mineral accumulation rates were higher in salt marshes and at low-marsh stations within individual sites. The average carbon sequestration rate based on 210Pb dating was 79 g C m−2 year−1, with slightly higher rates based on 137Cs dating. There was little difference in the sequestration rates among sites or across stations within sites, indicating that a single carbon sequestration rate could be used for crediting tidal wetland restoration projects within the Estuary. This data release is associated with the following publication in Estuaries and Coasts: https://doi.org/10.1007/s12237-012-9508-9.
| Start date | End date |
|---|---|
| 2008 | 2011 |
| Rank name | Value |
|---|---|
| Species | Distichlis spicata |
| Species | Scirpus acutus |
| Species | Schoenoplectus californicus |
| Species | Triglochin maritima |
| Species | Typa domingensis |
| Species | Cuscuta salina |
| Species | Grindelia stricta |
| Species | Sarcocornia pacifica |
| Species | Spartina foliosa |
| Species | Bolboschoenus maritimus |
| Species | Scirpus americanus |
| Species | Frankenia salina |
| Species | Jaumea carnosa |
| Species | Juncus balticus |
| 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. | |
| coring_method | Code indicating what type of device was used to collect soil depth profiles. | hargas corer = A large diameter (>10 cm) coring device consisting of a tube, piston, and a cutting head |
| compaction_flag | Code indicating how the authors qualified or quantified compaction of the core. | compaction qualified = Compaction was at least qualified and noted by the authors |
| dry_bulk_density_temperature | Temperature at which samples were dried to measure dry bulk density. This can include either samples that were freeze dried or oven dried. | celsius |
| dry_bulk_density_time | Time over which samples were dried to measure dry bulk density. | hour |
| 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 |
| 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 |
| fraction_carbon_method | Code indicating the method for which fraction carbon was measured or modeled (Note: regression based models are permitted, but the use of the Bemmelen factor [0.58 gOC gOM-1] is discouraged). | EA = Each sample presented was measured using Elemental Analysis |
| cs137_counting_method | Code indicating the method used for determining radiocesium activity. | gamma = Gamma counting method used. |
| pb210_counting_method | Code indicating the method used for determining lead 210 activity. | gamma = Gamma counting method used. |
| excess_pb210_rate | Code indicating the mass or accretion rate used in the excess_pb_210_model | accretion = Excess 210Pb modeled using vertical accretion rate. |
| excess_pb210_model | Code indicating the model used to estimate excess lead 210. | CIC = Constant initial concentration model used |
| 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. | |
| site_id | Site identification code unique to each study. | |
| core_id | Core identification code unique to each site. | |
| core_date | Date of core collection. | YYYY-MM-DD |
| core_latitude | Positional latitude of the core in decimal degree WGS84. | degree |
| core_longitude | Positional longitude of the core in decimal degree WGS84. | degree |
| core_position_method | Code indicating how latitude and longitude were determined. | RTK-GPS = Real-time kinematic global position system (GPS) handheld = Conventional Commercially available hand-held GPS |
| core_elevation | Surface elevation of the core relative to defined datum. | meter |
| core_elevation_datum | The datum relative to which the core elevation was measured against (For a complete list of datum names and aliases please refer to the ISO Geodedic Registry https://iso.registry.bespire.eu/register/geodetic/VerticalDatum). | NAVD88 = A gravity-based geodetic datum, North American Vertical Datum of 1988 |
| core_elevation_method | Code indicating how elevation was determined | RTK-GPS = Real-time kinematic global position system (GPS) |
| salinity_class | Code based on submitter field observation or measurement indicating average annual salinity (Note: Palustrine and freshwater should only include tidal wetlands, or wetlands that are potentially/formerly tidal but artificially freshened due to artificial tidal restrictions). | saline = 30-50 ppt brackish = 0.5-30 ppt |
| vegetation_class | Code based on submitter field observations or measurement indicating dominant wetland vegetation type. | emergent = Describes wetlands dominated by persistent emergent vascular plants |
| inundation_class | Code based on submitter field observation or measurement indicating how often the coring location is inundated. | high = Study-specific definition of an elevation relatively high in the tidal frame, typically defined by vegetation type mid = Study-specific definition of an elevation in the relative middle of the tidal frame, typically defined by vegetation type low = Study-specific definition of an elevation in relatively low in the tidal frame, typically defined by vegetation type |
| cs137_accretion_rate | Accretion rate measured using downcore distributions of 137Cs | centimeterPerYear |
| cs137_mineral_accumulation_rate | Mineral accumulation rate measured using downcore distributions of 137Cs | gramsPerSquareMeterPerYear |
| cs137_carbon_accumulation_rate | Carbon accumulation rate measured using downcore distributions of 137Cs | gramsPerSquareMeterPerYear |
| pb210_accretion_rate | Accretion rate measured using downcore distributions of 210Pb | centimeterPerYear |
| pb210_mineral_accumulation_rate | Mineral accumulation rate measured using downcore distributions of 210Pb | gramsPerSquareMeterPerYear |
| pb210_carbon_accumulation_rate | Carbon accumulation rate measured using downcore distributions of 210Pb | gramsPerSquareMeterPerYear |
| 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. | |
| site_id | Site identification code unique to each study. | |
| core_id | Core identification code unique to each site. | |
| 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. This does not include ash free bulk density. | gramsPerCubicCentimeter |
| fraction_organic_matter | Mass of organic matter relative to sample dry mass. Ash free bulk density should not be used here but should be expressed as a loss on ignition fraction. | dimensionless |
| fraction_carbon | Mass of carbon relative to sample dry mass. | dimensionless |
| cs137_activity | Radioactivity counts per unit dry weight for radiocesium (137Cs). | picocuriesPerGram |
| excess_pb210_activity | Excess radioactivity counts per unit dry weight for excess lead 210 (210Pb). | picocuriesPerGram |
| bi214_activity | Radioactivity counts per unit dry weight for Bismuth 214 (bi214) | becquerelsPerKilogram |
| depth_interval_notes | Any other submitter generated notes specific to the depth interval. |
| 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. | |
| site_id | Site identification code unique to each study. | |
| core_id | Core identification code unique to each site. | |
| impact_class | Code indicating any major anthropogenic impacts historically and currently affecting the coring location. | tidally restored = Tidal flow has been restored by removing an artificial obstruction |
| unit name | parent SI unit | unit type | description |
|---|---|---|---|
| picocuriesPerGram | radionucleotideActivityPerMass | picocuries per gram | |
| becquerelsPerKilogram | radionucleotideActivityPerMass | becquerels per kilogram | |
| gramsPerSquareMeterPerYear | massPerArealMassDensityRate | grams per square meter per year |
This dataset is listed under a Creative Commons BY 4.0 and can be used with attribution. https://creativecommons.org/licenses/by/4.0/