uid=MCM,o=EDI,dc=edirepository,dc=org all public read VG_DESORP Joel Singley

Institute of Arctic and Alpine Research Boulder CO 80303 US

joel.singley@colorado.edu https://orcid.org/0000-0002-7906-8491 Michael Gooseff michael.gooseff@colorado.edu http://goosefflab.weebly.com https://orcid.org/0000-0003-4322-8315 Eve-Lyn Hinckley eve.hinckley@colorado.edu https://orcid.org/0000-0002-7081-0530 McMurdo Dry Valleys LTER http://mcmlter.org/ Renée Brown rfbrown@unm.edu https://orcid.org/0000-0002-4986-7663 data manager 2021-03-25 English

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. 

ammonium hyporheic zone inorganic nitrogen nitrate nitrogen nitrogen cycling sediments LTER Controlled Vocabulary ammonium hyporheic zone inorganic nitrogen LTER McMurdo Dry Valleys nitrate nitrogen sediment Taylor Valley Station Keywords inorganic nutrients LTER Core Areas

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https://mcm.lternet.edu/content/ammonium-desorption-hyporheic-sediments-von-guerard-stream-mcmurdo-dry-valleys-antarctica Transect type is "pool." Coordinates provided by Ruth Heindel on 24 September 2020. 163.289283000000 163.289283000000 -77.619583000000 -77.619583000000 2019-01-10 McMurdo Dry Valleys LTER Information Manager im@mcmlter.org McMurdo Dry Valleys LTER http://mcmlter.org/ McMurdo Dry Valleys LTER

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.

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. mcmlter-strm-singley-vg_desorp-20210325.csv 10668 1 1 column , " https://mcm.lternet.edu/sites/default/files/data/mcmlter-strm-singley-vg_desorp-20210325.csv DATASET_CODE Dataset code Internal dataset code representing Von Guerard sediment desorption assay. string Internal dataset code representing Von Guerard sediment desorption assay. STRMGAGEID Stream Gage ID Code representing stream gage station. string Code representing stream gage station. STREAM_NAME Stream name Name of stream. string Name of stream. SAMPLE_ID 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. string 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 Sample type Alphanumeric code identifying sample type. Sample = treated sediment sample; solution_blank = treatment solution without sediment. string Alphanumeric code identifying sample type. Sample = treated sediment sample; solution_blank = treatment solution without sediment. LATERAL_POSITION 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. string 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. SC_US_CM Specific conductivity Actual specific conductivity of treatment solution microSiemensPerCentimeter real WET_SED_MASS_G Wet sediment mass Initial sediment mass under field moisture conditions. grams real VWC Volumetric water content Volumetric water content in decimal percent. string Volumetric water content in decimal percent. DRY_SED_MASS_G Dry sediment mass Estimated dry sediment mass based on WET_SED_MASS_g and VWC. grams real SOL_VOL Solution volume Treatment solution volume added to sample. milliliter real K_MGL Potassium concentration Concentration of potassium. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. milligramsPerLiter real CL_MGL Chloride concentration Concentration of chloride. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. milligramsPerLiter real NH4_MGL Ammonium concentration Concentration of nitrogen as ammonium. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. milligramsPerLiter real NH4_UG_G_DRY_SED 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. microgramsPerGram real NO3_MGL Nitrate concentration Concentration of nitrogen as nitrate plus nitrite. See COMMENTS for details regarding blank cells. ND = not detected, NM = not measured. milligramsPerLiter real NO3_UG_G_DRY_SED 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. microgramsPerGram real COMMENTS Comments Comments regarding blank cells. string Comments regarding blank cells. Derivative of the standard SI unit of electrical conductance (specific conductance).