Joel G. SingleyMichael N. GooseffEve-Lyn Hinckley 2021-03-25 tabular digitial data McMurdo Dry Valleys LTER McMurdo Dry Valleys LTER 10.6073/pasta/89e07484a91d8b503ae19d772555fbb4 https://mcm.lternet.edu/content/ammonium-desorption-hyporheic-sediments-von-guerard-stream-mcmurdo-dry-valleys-antarctica This data package provides analytic results for a laboratory assay on sediment samples collected in January 2019 from a transect (“P2”) across Von Guerard Stream (as described by Heindel et al. 2021), located in Taylor Valley, McMurdo Dry Valleys, Antarctica. We used excess sample from that study in a laboratory desorption assay to assess conductivity dependent desorption of ammonium. The assay was performed by mixing samples with potassium chloride treatment solutions that replicate the range of specific conductivities observed in Von Guerard Stream, shaking and centrifuging slurries, and analyzing filtered supernatant.  2019-01-10 ground condition As needed Transect type is "pool." Coordinates provided by Ruth Heindel on 24 September 2020. 163.289283000000 163.289283000000 -77.619583000000 -77.619583000000 LTER Core Areas inorganic nutrients None <cntperp> <cntper>McMurdo Dry Valleys LTER Information Manager</cntper> </cntperp> <cntemail>im@mcmlter.org</cntemail> 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 in January 2019 along a transect P2 as reported by Heindel et al. 2021. Sediment sampling methods, metadata, and information regarding total extractable ammonium and additional ancillary data are also reported by Heindel et al. 2021. We utilized subsamples from the P2 (pool morphology) transect. Wet sediment subsamples were weighed in triplicate for each sampling location (1-5) into sterile 250 mL HDPE wide mouth bottles and kept frozen (-20 ºC) prior to running the assay. For the assay, we prepared five solutions of varying conductivities using potassium chloride. The specific conductivity of each treatment solution was measured using a benchtop probe and a three or four point calibration. Sediment samples were removed from the freezer and treatment solution was added to each bottle to achieve a 2:5 sediment:solution ratio by mass. Bottles were inverted three times and placed on a shaker table at 300 rpm for 1 hour. Slurries were centrifuged at 3000 rpm for 5 minutes and then the supernatant was filtered through glass fiber filters (GF/F) and stored frozen prior to analysis. Supernatant aliquots were analyzed by the Arikaree Environmental Laboratory at the University of Colorado Boulder. Potassium was measured by Method EPA 7000B on a Perkin Elmer Model AAnalyst 200 Atomic Absorption Spectrometer with a limit of detection of 0.004 mg K+ per liter. Chloride was measured by Method EPA 300.1 on a Metrohm 930 Compact IC Flex with a limit of detection of 0.03 mg Cl- per liter. Nitrogen as ammonium measured by Method 10-107-06-1-A on a Lachat Quickchem Flow Injection Autoanalyzer with a limit of detection of 0.005 mg N per liter. Nitrogen as nitrate plus nitrite measured by Methods 10-107-04-1-A and 10-117-07-1-B on a Lachat Quickchem Flow Injection Autoanalyzer with a limit of detection of 0.002 mg N per liter. Samples were collected in the lower reaches of Von Guerard stream in January 2019 along a transect P2 as reported by Heindel et al. 2021. Sediment sampling methods, metadata, and information regarding total extractable ammonium and additional ancillary data are also reported by Heindel et al. 2021. We utilized subsamples from the P2 (pool morphology) transect. Wet sediment subsamples were weighed in triplicate for each sampling location (1-5) into sterile 250 mL HDPE wide mouth bottles and kept frozen (-20 ºC) prior to running the assay.For the assay, we prepared five solutions of varying conductivities using potassium chloride. The specific conductivity of each treatment solution was measured using a benchtop probe and a three or four point calibration. Sediment samples were removed from the freezer and treatment solution was added to each bottle to achieve a 2:5 sediment:solution ratio by mass. Bottles were inverted three times and placed on a shaker table at 300 rpm for 1 hour. Slurries were centrifuged at 3000 rpm for 5 minutes and then the supernatant was filtered through glass fiber filters (GF/F) and stored frozen prior to analysis.Supernatant aliquots were analyzed by the Arikaree Environmental Laboratory at the University of Colorado Boulder. Potassium was measured by Method EPA 7000B on a Perkin Elmer Model AAnalyst 200 Atomic Absorption Spectrometer with a limit of detection of 0.004 mg K+ per liter. Chloride was measured by Method EPA 300.1 on a Metrohm 930 Compact IC Flex with a limit of detection of 0.03 mg Cl- per liter. Nitrogen as ammonium measured by Method 10-107-06-1-A on a Lachat Quickchem Flow Injection Autoanalyzer with a limit of detection of 0.005 mg N per liter. Nitrogen as nitrate plus nitrite measured by Methods 10-107-04-1-A and 10-117-07-1-B on a Lachat Quickchem Flow Injection Autoanalyzer with a limit of detection of 0.002 mg N per liter. unknown VG_DESORP This data table provides sediment sample information and concentrations of analytes for extraction solution blanks and sample aliquots. Data are organized by sampling location and treatment. Dataset code Internal dataset code representing Von Guerard sediment desorption assay. The data provider Internal dataset code representing Von Guerard sediment desorption assay. Stream Gage ID Code representing stream gage station. The data provider Code representing stream gage station. Stream name Name of stream. The data provider Name of stream. Sample ID Alphanumeric code indicating lateral location of sample on transect, treatment, and replicate id. 1-5 = lateral location from wetted margin on stream left to wetted margin on stream right, with 3 at the thalweg; 0,40,80,160,320 indicate treatment solution conductivity; A-C indicate replicate identifier. The data provider Alphanumeric code indicating lateral location of sample on transect, treatment, and replicate id. 1-5 = lateral location from wetted margin on stream left to wetted margin on stream right, with 3 at the thalweg; 0,40,80,160,320 indicate treatment solution conductivity; A-C indicate replicate identifier. Sample type Alphanumeric code identifying sample type. Sample = treated sediment sample; solution_blank = treatment solution without sediment. The data provider Alphanumeric code identifying sample type. Sample = treated sediment sample; solution_blank = treatment solution without sediment. Lateral position Sample location identifier from lateral transect across stream. 1-5 = lateral location from wetted margin on stream left to wetted margin on stream right, with 3 at the thalweg. The data provider Sample location identifier from lateral transect across stream. 1-5 = lateral location from wetted margin on stream left to wetted margin on stream right, with 3 at the thalweg. Specific conductivity Actual specific conductivity of treatment solution The data provider microSiemensPerCentimeter Wet sediment mass Initial sediment mass under field moisture conditions. The data provider grams Volumetric water content Volumetric water content in decimal percent. The data provider Volumetric water content in decimal percent. Dry sediment mass Estimated dry sediment mass based on WET_SED_MASS_g and VWC. The data provider grams Solution volume Treatment solution volume added to sample. The data provider milliliter Potassium concentration Concentration of potassium. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. The data provider milligramsPerLiter Chloride concentration Concentration of chloride. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. The data provider milligramsPerLiter Ammonium concentration Concentration of nitrogen as ammonium. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. The data provider milligramsPerLiter Normalized ammonium concentration Normalized mass of nitrogen as ammonium per gram of dry sediment. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. The data provider microgramsPerGram Nitrate concentration Concentration of nitrogen as nitrate plus nitrite. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. The data provider milligramsPerLiter Normalized nitrate concentration Normalized mass of nitrogen as nitrate plus nitrite per gram of dry sediment. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. The data provider microgramsPerGram Comments Comments regarding blank cells. The data provider Comments regarding blank cells. 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-vg_desorp-20210325.csv None 2021-03-25 2021-03-25 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. 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