Joel G. SingleyMichael N. GooseffDiane M. McKnightEve-Lyn Hinckley 2020-07-09 tabular digitial data McMurdo Dry Valleys LTER McMurdo Dry Valleys LTER 10.6073/pasta/d6e4301bf93fba0fef6fd5c33a092aaf https://mcm.lternet.edu/content/surface-and-hyporheic-porewater-chemistry-and-sediment-nitrification-potentials-von-guerard Surface water and hyporheic porewater samples were collected at high frequency during the 2017-18 (01/20/2018-01/21/2018) and 2018-19 (01/10/2019-01/12/2019) flow seasons, and opportunistically throughout the 2019-20 flow season (12/17/2019-1/25/2020) from the lower reaches of Von Guerard Stream, Taylor Valley, McMurdo Dry Valleys, Antarctica. Porewater samples were collected using plastic tubing inserted to depths of 15 or 30 cm and drawn out by syringe. This data package includes sampling locations and water chemistry data (including concentrations for dissolved organic nitrogen species, dissolved organic carbon, silica, as well as water isotopes). A laboratory nitrification potential assay was performed on sediments collected from Von Guerard stream during the 2017-18 flow season to assess the functional microbial potential of the hyporheic microbial community to perform nitrification.  2018-01-20 2020-01-25 ground condition As needed USGS site 5; coordinates taken from 1996-97 GPS measurements at center of weir Parent Stream: Von Guerard Stream Provenance : GPS96-97.DOC ID: vguerard_f6 163.253997802734 163.253997802734 -77.608200073242 -77.608200073242 19m 19m meter LTER Core Areas inorganic nutrients None <cntperp> <cntper>McMurdo Dry Valleys LTER Information Manager</cntper> </cntperp> <cntemail>im@mcmlter.org</cntemail> Name: Kathleen A. Welch Role: lab technician Name: Anna J. Bergstrom Role: lab technician Name: Renée F. Brown Role: data manager Not Applicable Not Applicable Field and/or Lab Methods Samples were collected in the lower reaches of Von Guerard stream from below the playa to about 200 m upstream of the F6 gage. Samples were taken on lateral transects extending from the channel center to the wetted margin. Full transect locations are included as a csv file. Porewater samplers were flexible polyethylene tubing (3/16” inner diameter) encased in a rigid plastic tube and screened at the bottom with fine metal mesh. We installed samplers to depths of both 15 and 30 cm at locations A-D on each transect. Nutrient and DOC samples were filtered through pre-combusted (4 hr at 450ºC) Whatman GF/C glass fiber filters. Nutrient samples were stored frozen in 60 mL HDPE bottles, while DOC and isotope samples were kept chilled (+4ºC) in the dark prior to analysis. Silica and DIN were measured colorimetrically immediately after thawing at room temperature by the Arikaree Environmental Laboratory, University of Colorado Boulder, using a Lachat (USA) QuikChem 8500 Flow Injection Autoanalyzer. Nitrate (as NO3– + NO2–) was analyzed by standard method 4500-NO3 I (cadmium reduction flow injection) with a detection limit of 0.004 mg NO3––N L–1. Samples were analyzed for NH4+ by standard method 4500-NH3 H (phenolate flow injection, detection limit of 0.005 mg NH4+–N L–1). For Si, the detection limit was 0.004 mg Si L–1 by standard method 4500-SiO2 F. We measured water isotopes (δ18O and δD) using a cavity ring-down spectrometer (Picarro, USA) and calculated deuterium excess as δD – 8*δ18O. For the nitrification potential assay we used sediment from two pilot transects during January 2018. We first removed the top 5 cm of the streambed to avoid contamination from benthic algal mats, then scooped sediment from approximately 5–10 cm depth into sterile Whirlpaks. These sediment samples were stored frozen and shipped to the University of Colorado Boulder for analysis. After thawing the samples at room temperature, we subsampled 20 g of wet sediment from each site in triplicate into sterile 250 mL HDPE bottles and an additional 20 g in triplicate into pre-weighed aluminum weigh boats. We dried the subsamples in the aluminum weigh boats at 105ºC for 24 hours and reweighed to calculate mean volumetric water content for each sampling location. For the samples in 250 mL HDPE bottles, we performed a nitrification potential assay using perchlorate and NH4+ in a phosphate (KH2PO4 and K2HPO4) buffered solution, which was mixed constantly with the sediment on a shaker table at room temperature. A detailed description of the assay protocol and solution concentrations is provided by Schmidt &amp; Belser [1994]. We took subsamples from each replicate flask at 0, 1 and 8 hours then 1, 2, 3, and 5 days from the start of the assay. All subsamples were immediately filtered through Whatman GF/C glass fiber filters and stored frozen (-20ºC) until thawed for analysis. As perchlorate in the incubation solution inhibits the final oxidation of nitrite (NO2–) to NO3–, we analyzed the filtered aliquots for NO2– colorimetrically using a Lachat QuikChem 8500 Flow Injection Autoanalyzer. Accumulated NO2– concentrations were converted to mass NO2––N normalized by the calculated dry weight of sediment in each replicate flask. Samples were collected in the lower reaches of Von Guerard stream from below the playa to about 200 m upstream of the F6 gage. Samples were taken on lateral transects extending from the channel center to the wetted margin. Full transect locations are included as a csv file.Porewater samplers were flexible polyethylene tubing (3/16” inner diameter) encased in a rigid plastic tube and screened at the bottom with fine metal mesh. We installed samplers to depths of both 15 and 30 cm at locations A-D on each transect. Nutrient and DOC samples were filtered through pre-combusted (4 hr at 450ºC) Whatman GF/C glass fiber filters. Nutrient samples were stored frozen in 60 mL HDPE bottles, while DOC and isotope samples were kept chilled (+4ºC) in the dark prior to analysis. Silica and DIN were measured colorimetrically immediately after thawing at room temperature by the Arikaree Environmental Laboratory, University of Colorado Boulder, using a Lachat (USA) QuikChem 8500 Flow Injection Autoanalyzer. Nitrate (as NO3– + NO2–) was analyzed by standard method 4500-NO3 I (cadmium reduction flow injection) with a detection limit of 0.004 mg NO3––N L–1. Samples were analyzed for NH4+ by standard method 4500-NH3 H (phenolate flow injection, detection limit of 0.005 mg NH4+–N L–1). For Si, the detection limit was 0.004 mg Si L–1 by standard method 4500-SiO2 F. We measured water isotopes (δ18O and δD) using a cavity ring-down spectrometer (Picarro, USA) and calculated deuterium excess as δD – 8*δ18O.For the nitrification potential assay we used sediment from two pilot transects during January 2018. We first removed the top 5 cm of the streambed to avoid contamination from benthic algal mats, then scooped sediment from approximately 5–10 cm depth into sterile Whirlpaks. These sediment samples were stored frozen and shipped to the University of Colorado Boulder for analysis. After thawing the samples at room temperature, we subsampled 20 g of wet sediment from each site in triplicate into sterile 250 mL HDPE bottles and an additional 20 g in triplicate into pre-weighed aluminum weigh boats. We dried the subsamples in the aluminum weigh boats at 105ºC for 24 hours and reweighed to calculate mean volumetric water content for each sampling location. For the samples in 250 mL HDPE bottles, we performed a nitrification potential assay using perchlorate and NH4+ in a phosphate (KH2PO4 and K2HPO4) buffered solution, which was mixed constantly with the sediment on a shaker table at room temperature. A detailed description of the assay protocol and solution concentrations is provided by Schmidt & Belser [1994]. We took subsamples from each replicate flask at 0, 1 and 8 hours then 1, 2, 3, and 5 days from the start of the assay. All subsamples were immediately filtered through Whatman GF/C glass fiber filters and stored frozen (-20ºC) until thawed for analysis. As perchlorate in the incubation solution inhibits the final oxidation of nitrite (NO2–) to NO3–, we analyzed the filtered aliquots for NO2– colorimetrically using a Lachat QuikChem 8500 Flow Injection Autoanalyzer. Accumulated NO2– concentrations were converted to mass NO2––N normalized by the calculated dry weight of sediment in each replicate flask. unknown VGPW_CHEM Water chemistry data for concurrent surface and porewater samples, organized by sampling location, sampling time, and solute (DIN species, DOC, and water isotopes). Dataset Code Internal dataset code. The data provider Internal dataset code. Stream Gage ID Stream Gage ID. The data provider Stream Gage ID. Stream Name Name of the stream. The data provider Name of the stream. Sample ID Alphanumeric code indicating sample year and sequential number. The data provider Alphanumeric code indicating sample year and sequential number. Date and Time Date and time of sample collection (MM/DD/YYYY HH:MM UTC+13). The data provider calendar date/time MM/DD/YYYY HH:MM UTC+13 gregorian calendar Sample Type Type of sample. The data provider surface surface water The data provider pore hyporheic porewater The data provider Sample Year Year of sample collection. The data provider calendar date/time YYYY gregorian calendar Transect Alphanumeric code identifying longitudinal transect, numbered from upstream to downstream. Transect locations shifted among years as noted in the associated data table ‘VGPW_LOCATIONS’. T1 = Transect 1, and so on. The data provider Alphanumeric code identifying longitudinal transect, numbered from upstream to downstream. Transect locations shifted among years as noted in the associated data table ‘VGPW_LOCATIONS’. T1 = Transect 1, and so on. Site Letter identifying the lateral location on the transect. Values for lateral porewater sites are A-D with A at the channel center and D the wetted margin. SW indicates surface water. The data provider Letter identifying the lateral location on the transect. Values for lateral porewater sites are A-D with A at the channel center and D the wetted margin. SW indicates surface water. Sample depth For pore samples, indicates the depth of sampler intake below streambed surface, where 0 = surface water, 15 = 15 cm, and 30 = 30 cm. The data provider centimeter Nitrate concentration Concentration of nitrogen as nitrate + nitrite in milligrams of nitrogen per liter. The data provider milligramsPerLiter Nitrate Concentration Comments Comments regarding nitrate concentrations, where ND = not detected and NM = not measured. The data provider Comments regarding nitrate concentrations, where ND = not detected and NM = not measured. Ammonium concentration Concentration of nitrogen as ammonium in milligrams of nitrogen per liter. The data provider milligramsPerLiter Ammonium Concentration Comments Comments regarding ammonium concentrations, where ND = not detected and NM = not measured. The data provider Comments regarding ammonium concentrations, where ND = not detected and NM = not measured. Dissolved silica concentration Dissolved silica concentration in milligrams of silica per liter. The data provider milligramsPerLiter Dissolved Silica Concentration Comments Comments regarding dissolved silica concentrations, where ND = not detected and NM = not measured. The data provider Comments regarding dissolved silica concentrations, where ND = not detected and NM = not measured. Dissolved organic carbon Dissolved organic carbon concentration in milligrams of carbon per liter. The data provider milligramsPerLiter Comments regarding DOC Comments regarding dissolved organic carbon concentrations, where ND = not detected and NM = not measured. The data provider Comments regarding dissolved organic carbon concentrations, where ND = not detected and NM = not measured. Oxygen-18 Isotope Ratio δ18O isotope ratio reported in reported in parts per thousand (per mil, ‰). The data provider perMil Deuterium Isotope Ratio δD isotope ratio reported in reported in parts per thousand (per mil, ‰). The data provider perMil Deuterium excess Deuterium excess as calculated by δD-8*δ18O. The data provider perMil Comments regarding isotopes Comments regarding all isotope values, where ND = not detected and NM = not measured. The data provider Comments regarding all isotope values, where ND = not detected and NM = not measured. Specific conductivity Specific conductivity in microSiemens per centimeter. The data provider microSiemensPerCentimeter Comments regarding specific conductivity Comments regarding specific conductivity, where ND = not detected and NM = not measured. The data provider Comments regarding specific conductivity, where ND = not detected and NM = not measured. Inundation Code Identifies whether sampling location was inundated by surface water at time of sample collection. Surface water samples are noted with “Yes”. The data provider Yes Inundated The data provider No Not inundated The data provider McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-strm-singley-vgpw-chemistry-20210325.csv None VGPW_LOCATIONS Location information for sampling transects along Von Guerard Stream. Dataset Code Internal dataset code. The data provider Internal dataset code. Stream Gage ID Stream gage ID. The data provider Stream gage ID. Stream Name Name of the stream. The data provider Name of the stream. Transect Alphanumeric transect identifier, number increases from upstream to downstream. The data provider Alphanumeric transect identifier, number increases from upstream to downstream. Sample Year Year in which sample was collected. The data provider calendar date/time YYYY gregorian calendar Latitude Sampling transect latitude. The data provider decimalDegrees Longitude Sampling transect longitude. The data provider decimalDegrees McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-strm-singley-vgpw-locations-20210325.csv None VGPW_NITRIFICATION Laboratory nitrification potential assay data for sediments collected from Von Guerard Stream.  Dataset code Internal dataset code. The data provider Internal dataset code. Stream Gage ID Stream Gage ID. The data provider Stream Gage ID. Stream Name Name of the stream. The data provider Name of the stream. Sample ID Code indicating sediment sample location, prior to replication. The data provider Code indicating sediment sample location, prior to replication. Sample Year Year sample was collected. The data provider calendar date/time YYYY gregorian calendar Transect. Alphanumeric transect identifier, number increases from upstream to downstream. The data provider Alphanumeric transect identifier, number increases from upstream to downstream. Site Lateral site on the transect. The data provider A Center of channel The data provider C Wetted margin The data provider Replicate Replicate identifier within the same sampling site. The data provider Replicate identifier within the same sampling site. Elapsed Time Time (in days) since the beginning of the nitrification potential assay. The data provider day Nitrite concentration Concentration of nitrogen as nitrite in aliquot, reported in micrograms of nitrogen per liter. The data provider microgramsPerLiter Comments regarding nitrate concentration Comments regarding nitrate concentration, where NM = not measured. The data provider Comments regarding nitrate concentration, where NM = not measured. Dry mass of sediment Dry mass of sediment in flask, reported as grams of sediment. The data provider grams Volume Volume of incubation solution in liters. The data provider liter Nitrate concentration normalized to dry mass sediment Nitrogen as nitrate concentration normalized to dry mass sediment, reported as micrograms of nitrogen per kilogram of sediment. The data provider microgramsPerKilogram McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-strm-singley-vgpw-nitrification-20200820.csv None 2020-07-09 2020-07-09 McMurdo Dry Valleys LTER http://mcmlter.org/ Biological Data Profile of the Content Standards for Digital Geospatial Metadata devised by the Federal Geographic Data Committee. Drupal Ecological information Management Systems, version D7, Biological Data Profile module