Anna J. BergstromMichael N. Gooseff 2020-02-12 tabular digitial data McMurdo Dry Valleys LTER McMurdo Dry Valleys LTER 10.6073/pasta/2afe506b7741c0ce5dd90c2f685910f5 https://mcm.lternet.edu/content/nutrient-addition-incubation-experiments-using-sediments-supraglacial-streams-taylor-valley We used sediment incubations to quantify and compare nutrient uptake rates from biota living in sediment across glaciers in Taylor Valley, Antarctica. Hughes Glacier is located towards the polar plateau on the western edge of the valley and flows from the southern Kukri Hills north into the valley. Canada and Commonwealth glaciers flow south into the valley from the Asgard range. Commonwealth glacier is located closest to the ocean on the east end of the valley. Canada glacier is located mid-valley, between Hughes and Commonwealth glaciers. Sediment was brought to the lab and incubated with added nutrient solutions. Solutions were then analyzed to determine change in nutrient concentration.  2017-12-15 2017-12-17 ground condition As needed Hughes Glacier is a small alpine glacier flowing toward Lake Bonney in Taylor Valley from the Kukri Hills on the south. Named for Professor McKenny Hughes. 162.581527709961 162.437667846680 -77.727073669434 -77.749969482422 The Canada Glacier a small glacier flowing south-east into the northern side of Taylor Valley.  The glacier receives less than 10 cm of snowfall annually. Its seasonal melting feeds Lake Hoare to the west and Lake Fryxell to the east. 163.057708740234 162.894287109375 -77.598403930664 -77.632133483887 The Commonwealth glacier flows in a southeasterly direction and enters the northern side of Taylor Valley immediately west of Mount Coleman. Named by the British Antarctic Expedition for the Commonwealth of Australia in the early 1900s.   163.373565673828 163.197784423828 -77.545059204102 -77.589111328125 286m 286m meter LTER Core Areas inorganic nutrients None <cntperp> <cntper>McMurdo Dry Valleys LTER Information Manager</cntper> </cntperp> <cntemail>im@mcmlter.org</cntemail> Name: Joel G. Singley Role: field crew Name: Kathleen A. Welch Role: lab technician Name: Renée F. Brown Role: data manager Not Applicable Not Applicable Field and/or Lab Methods We collected up to 10 kg of sediment from the main supraglacial stream networks of Commonwealth, Hughes, and Canada Glaciers. Specifically, sediment was collected from one location on the drainage network of three glaciers in Taylor Valley, Antarctica: Hughes Glacier (-77.73054167, 162.4337083), Canada Glacier (-77.62767, 162.96059), and Commonwealth Glacier (-77.58606667, 163.2535667). Sediment was collected using sterilized scoops, placed in Whirl-Paks and frozen for transport back to McMurdo Station. In the lab, we thawed and homogenized sediment. For each glacier, we autoclaved half the sediment at 120 C for 35 minutes. Sediment moisture content remained consistent before and after autoclaving. We then divided live and autoclaved sediments into 50 g (+/- 0.5 g) subsets and placed into a sterile 250 ml cell culture flask. We stored all flasks at -20 C until they were ready to be treated with 125 ml of a nutrient solution and placed directly into a cold water bath. Solutions were NH4Cl, NaNO3-, KH2PO43-, NaNO3- + KH2PO43-, and a deionized water control. Initial concentrations of NH4+ NO3- and PO43– were 10, 10, and 4 uM, respectively. All flasks were incubated in a large open saltwater tank (to avoid freeze over and maintain thermal stability) outside at ambient air temperature (~0 C) and under ambient light conditions (300-700 W m-2). Due to the high number of replicates, we grouped incubations by glacier and the experiment was run over the course of three days.Two flasks, one containing live and the other autoclaved sediment of each treatment (8 flasks total) were removed from the cold-water bath each hour after the start of the incubation. 110 ml of water was removed and filtered (using GF/F filters) from each flask into a clean 125 ml polyethylene bottle. The filtrate was frozen at -20 C and shipped back to the University of Colorado-Boulder for analysis. We scooped a 25 g subsample of sediment from the incubation flask into a weigh boat, weighed, and dried overnight at 55 C. Sediment was then reweighed and burned at 450 C for 4 hours, and weighed a final time to calculate percent loss on ignition (LOI). The filters were also dried, burned, and weighed to calculate loss on ignition for suspended matter.In addition to the long-duration incubation experiments, we performed a ~5-minute incubation on live and autoclaved sediments for each treatment and each glacier in triplicate. Finally, we performed KCl extracts on five replicates of 10 g of live and autoclaved sediments for each glacier using 40 ml of 2M KCl solution and extracting on a shaker table for 1 hour. The extract solution was filtered and frozen at -20 C for later analysis. We performed analysis of all filtrate from treatments and KCl extracts for N as NO3¬, and P as PO43- by Lachat (Hach instruments). All samples analyzed for ammonium used a salicylate colorimetric method and microplate reader (BioTek Instruments, inc.) We collected up to 10 kg of sediment from the main supraglacial stream networks of Commonwealth, Hughes, and Canada Glaciers. Specifically, sediment was collected from one location on the drainage network of three glaciers in Taylor Valley, Antarctica: Hughes Glacier (-77.73054167, 162.4337083), Canada Glacier (-77.62767, 162.96059), and Commonwealth Glacier (-77.58606667, 163.2535667). Sediment was collected using sterilized scoops, placed in Whirl-Paks and frozen for transport back to McMurdo Station. In the lab, we thawed and homogenized sediment. For each glacier, we autoclaved half the sediment at 120 C for 35 minutes. Sediment moisture content remained consistent before and after autoclaving. We then divided live and autoclaved sediments into 50 g (+/- 0.5 g) subsets and placed into a sterile 250 ml cell culture flask. We stored all flasks at -20 C until they were ready to be treated with 125 ml of a nutrient solution and placed directly into a cold water bath. Solutions were NH4Cl, NaNO3-, KH2PO43-, NaNO3- + KH2PO43-, and a deionized water control. Initial concentrations of NH4+ NO3- and PO43– were 10, 10, and 4 uM, respectively. All flasks were incubated in a large open saltwater tank (to avoid freeze over and maintain thermal stability) outside at ambient air temperature (~0 C) and under ambient light conditions (300-700 W m-2). Due to the high number of replicates, we grouped incubations by glacier and the experiment was run over the course of three days.Two flasks, one containing live and the other autoclaved sediment of each treatment (8 flasks total) were removed from the cold-water bath each hour after the start of the incubation. 110 ml of water was removed and filtered (using GF/F filters) from each flask into a clean 125 ml polyethylene bottle. The filtrate was frozen at -20 C and shipped back to the University of Colorado-Boulder for analysis. We scooped a 25 g subsample of sediment from the incubation flask into a weigh boat, weighed, and dried overnight at 55 C. Sediment was then reweighed and burned at 450 C for 4 hours, and weighed a final time to calculate percent loss on ignition (LOI). The filters were also dried, burned, and weighed to calculate loss on ignition for suspended matter.In addition to the long-duration incubation experiments, we performed a ~5-minute incubation on live and autoclaved sediments for each treatment and each glacier in triplicate. Finally, we performed KCl extracts on five replicates of 10 g of live and autoclaved sediments for each glacier using 40 ml of 2M KCl solution and extracting on a shaker table for 1 hour. The extract solution was filtered and frozen at -20 C for later analysis. We performed analysis of all filtrate from treatments and KCl extracts for N as NO3¬, and P as PO43- by Lachat (Hach instruments). All samples analyzed for ammonium used a salicylate colorimetric method and microplate reader (BioTek Instruments, inc.) unknown GLACIER_SUPRA_MESOCOSM Nutrient Addition in Supraglacial Sediments Dataset code Internal dataset code. The data provider Internal dataset code. Sample ID Sample unique identifier. The data provider Sample unique identifier. Date Date on which incubation was conducted. The data provider calendar date/time MM/DD/YYYY gregorian calendar Duration Duration of the incubation in decimal hours, from the time nutrient solution was added to the time of filtering. The data provider decimalTime Glacier Name of the glacier (i.e., Canada, Commonwealth, or Hughes) from which the sample was collected. The data provider Name of the glacier (i.e., Canada, Commonwealth, or Hughes) from which the sample was collected. Autoclaved Whether or not the sample was autoclaved. The data provider Yes Sample was autoclaved. The data provider No Sample was not autoclaved (i.e., live). The data provider Treatment Nutrient solution or deionized water (DIW) added to sample. Options include NO3, NH4, PO4, NO3+PO4, DIW control, or KCl. The data provider Nutrient solution or deionized water (DIW) added to sample. Options include NO3, NH4, PO4, NO3+PO4, DIW control, or KCl. Phosphorous concentration Phosphorus concentration of solution after incubation. The data provider milligramsPerLiter Nitrate concentration Nitrate concentration of the solution after incubation. Any value of 0 is below the detection limit of the instrument. The data provider milligramsPerLiter Ammonium concentration Ammonium concentration of the solution after incubation. Any value of 0 is below the detection limit of the instrument. The data provider milligramsPerLiter Sediment dry mass Dry mass of sediment from incubation used for loss on ignition (LOI) analysis. The data provider gram Sediment dry mass after ignition Mass loss of sediment after burning in a muffle furnace (i.e., mass loss on ignition (LOI) ). The data provider gram Volume of solution filtered Volume of solution filtered from incubation flask. The data provider milliliter Filter mass after ignition Mass lost from filter after burning in a muffle furnace (i.e., mass loss on ignition (LOI) ). The data provider gram 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/GLACIER_SUPRA_MESOCOSM_0.csv None 2020-02-12 2020-02-12 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