STRM_MAT_ISOTOPES English utf8 dataset McMurdo Dry Valleys LTER Information Manager im@mcmlter.org pointOfContact 2023-04-20 ISO 19115-2 Geographic Information - North American Profile Metadata - Data with Biological Extensions ISO 19115-2:2009(E) Biomass, stoichiometry, and isotopic signatures of stream microbial mats, McMurdo Dry Valleys, Antarctica (2012-2013) 2023-04-20 publication Tyler Kohler Charles University https://www.cuni.cz/ tyler.j.kohler@gmail.com pointOfContact Diane McKnight University of Colorado Boulder http://www.colorado.edu/ diane.mcknight@colorado.edu pointOfContact documentDigital We conducted a field survey to quantify the biomass (chlorophyll-a and ash-free dry mass), nutrient ratios (molar C:N:P), and isotopic signatures (δ13C and δ15N) of four microbial mat types (green, orange, black, and red) in the glacial meltwater streams of the McMurdo Dry Valleys, Antarctica. All samples were taken from late December to late January during the 2011-2012 and 2012-2013 austral summers, and included sites from Taylor, Miers, Garwood, and Wright valleys. Most collection sites were located at the lake outlet of streams, but for a subset (e.g. Delta, Von Guerard, Onyx, Miers, and Canada) more than one sample site is included per stream system. Name: Renée F. Brown Role: data manager completed McMurdo Dry Valleys LTER Information Manager im@mcmlter.org pointOfContact inorganic nutrients primary production theme LTER Core Areas English Transect by Andersen Creek near Gage Moss Site M-01, H01Simm-G, H1 Transect 1 Points T011 and T012 mark the start and end of the transect. Start : IDs: 1ANDRSNT011 Ellipsoid: 23.73 ORTHOMETRIC HT (m) 78.97 End: ID: 1ANDRSNT012 Ellipsoid: 22.64 ORTHOMETRIC HT (m) 77.88 File provenance: strm-clg.txt 162.907409667969 162.906311035156 -77.622985839844 -77.622917175293 Transect by House Creek near Gage Moss Site M-02, H2 Transect 2 Points T021 and T022 mark the start and end of the transect. Start : IDs: 2HOUSET021 Ellipsoid: 30.21 ORTHOMETRIC HT (m) 85.42 End: ID: 2HOUSET022 Ellipsoid: 30.68 ORTHOMETRIC HT (m) 85.89 File provenance: strm-clg.txt 162.739685058594 162.739425659180 -77.643096923828 -77.643013000488 Transect by Canada Stream near Gage Moss Site M-03, F04Cana-G Transect 3 Points T031 and T032 mark the start and end of the transect. Start : IDs: 3CNGAGET031 Ellipsoid: 0.22 ORTHOMETRIC HT (m) 55.46 End: ID: 3CNGAGET032 Ellipsoid: -2.37 ORTHOMETRIC HT (m) 52.85 File provenance: strm-clg.txt 163.052688598633 163.050796508789 -77.613395690918 -77.613243103027 Transect by Canada Stream at Delta Moss Site M-04, F04Cana-D Transect 4 Points T041 and T042 mark the start and end of the transect. Start : IDs: 4CNDELTAT041 Ellipsoid: -30.52 ORTHOMETRIC HT (m) 24.72 End: ID: 4CNDELTAT042 Ellipsoid: -31.83 ORTHOMETRIC HT (m) 23.39 File provenance: strm-clg.txt 163.070114135742 163.069854736328 -77.614814758301 -77.614593505859 Transect by Von Guerard Stream at Upper Site Moss Site M-05 Transect 5 Points T051 and T052 mark the start and end of the transect. Start : IDs: 5VGUPPERT051 Ellipsoid: 114.08 ORTHOMETRIC HT (m) 169.27 End: ID: 5VGUPPERT052 Ellipsoid: 120.24 ORTHOMETRIC HT (m) 175.41 File provenance: strm-clg.txt 163.307327270508 163.305282592773 -77.634559631348 -77.634208679199 Transect by Von Guerard Stream at Lower Site Moss Site M-06 Transect 6 Points T061 and T062 mark the start and end of the transect. Start : IDs: 6VGLOWERT061 Ellipsoid: 33.99 ORTHOMETRIC HT (m) 89.19 End: ID: 6VGLOWERT062 Ellipsoid: 33.74 ORTHOMETRIC HT (m) 88.92 File provenance: strm-clg.txt 163.288482666016 163.287460327148 -77.619659423828 -77.619300842285 Transect by Delta Stream at Upper Site Moss Site M-07, F08Delt-U Transect 7 Points T071 and T072 mark the start and end of the transect. Start : IDs: 7DLTUPPERT071 Ellipsoid: 201.5 ORTHOMETRIC HT (m) 256.72 End: ID: 7DLTPPERT072 Ellipsoid: 201.53 ORTHOMETRIC HT (m) 256.73 File provenance: strm-clg.txt 163.099685668945 163.097671508789 -77.653213500977 -77.652854919434 Transect by Delta Stream at gage Moss Site M-08, F08Delt-G Transect 8 Points T081 and T082 mark the start and end of the transect. Start : IDs: 8DLTGAGET081, Ellipsoid: -23.45 ORTHOMETRIC HT (m) 31.78 End: ID: 8DLTGAGET082 Ellipsoid: -19.93 ORTHOMETRIC HT (m) 35.28 File provenance: strm-clg.txt 163.110809326172 163.108413696289 -77.625877380371 -77.625495910645 Transect by green Creek above gage Moss Site M-09, F09Green-G Transect 9 Points T091 and T092 mark the start and end of the transect. Start : IDs: 9GREENT091, Ellipsoid: -22.66 ORTHOMETRIC HT (m) 32.58 End: ID: 9GREENT092 Ellipsoid: -26.5 ORTHOMETRIC HT (m) 28.72 File provenance: strm-clg.txt 163.059310913086 163.058395385742 -77.624420166016 -77.623992919922 Transect by Bowles Creek near gage Moss Site M-10, F10Bowl-G Transect 10 Points T101 and T102 mark the start and end of the transect. Start : IDs: 10BOWLEST101, Ellipsoid: -25.54 ORTHOMETRIC HT (m) 29.7 End: ID: 10BOWLEST102 Ellipsoid: -24.01 ORTHOMETRIC HT (m) 31.24 File provenance: strm-clg.txt 163.057601928711 163.057083129883 -77.623336791992 -77.623100280762 Transect by Huey Creek near gage Moss Site M-11, F11Huey-G Transect 11 Points T111 and T112 mark the start and end of the transect. Start : IDs: 10BOWLEST111, Ellipsoid: -14.09 ORTHOMETRIC HT (m) 41.15 End: ID: 10BOWLEST112 Ellipsoid: -12.91 ORTHOMETRIC HT (m) 42.31 File provenance: strm-clg.txt 163.122741699219 163.121688842773 -77.602165222168 -77.601676940918 Transect by Von Guerard Stream at gage Moss Site M-12, F12Vong-G Transect 12 Points T121 and T122 mark the start and end of the transect. Start : IDs: 12VGGAGET121, Ellipsoid: -30.67 ORTHOMETRIC HT (m) 24.53 End: ID: 12VGGAGET122 Ellipsoid: -31.35 ORTHOMETRIC HT (m) 23.87 File provenance: strm-clg.txt 163.255294799805 163.253005981445 -77.609474182129 -77.609222412109 Moss Site 13 Transect 13 Points T131 and T132 mark the start and end of the transect. Start : IDs: 13PRISCUT131, Ellipsoid: 16.79 ORTHOMETRIC HT (m) 71.96 End: ID: 13PRISCUT132 Ellipsoid: 21.49 ORTHOMETRIC HT (m) 76.64 File provenance: strm-clg.txt 162.539794921875 162.537292480469 -77.696861267090 -77.696228027344 Transect by Lawson creek near gage Moss Site M-14, B14Laws-G Transect 14 Points T141 and T142 mark the start and end of the transect. Start : IDs: 14LAWSONT141, Ellipsoid: 24.08 ORTHOMETRIC HT (m) 79.13 End: ID: 14LAWSONT144 Ellipsoid: 30.05 ORTHOMETRIC HT (m) 85.08 File provenance: strm-clg.txt 162.268783569336 162.266586303711 -77.720619201660 -77.720359802246 Transect by Boehner Stream at lower site. B15Bohn-L Transect 15 Points T151 and T152 mark the start and end of the transect. Start : IDs: 15BOHNERT151 Ellipsoid: 74.57 ORTHOMETRIC HT (m) 129.74 End: ID: 15BOHNERT152 Ellipsoid: 70.17 ORTHOMETRIC HT (m) 125.32 File provenance: strm-clg.txt 162.563919067383 162.559936523438 -77.697700500488 -77.696968078613 Transect by Wharton Creek at Delta Moss Site M-16 Transect 16 Points T161 and T162 mark the start and end of the transect. Start : IDs: 16WHARTONT161 Ellipsoid: 24.1 ORTHOMETRIC HT (m) 79.31 End: ID: 16WHARTONT162 Ellipsoid: 23.61 ORTHOMETRIC HT (m) 78.82 File provenance: strm-clg.txt 162.746231079102 162.745101928711 -77.645057678223 -77.644943237305 ground condition 2012-01-10 2013-01-23 Funding: Provided by several grants from the National Science Foundation for Long Term Ecological Research including #OPP-1115245 and #OPP-1637708. Provenance: Ash-free dry mass and chlorophyll-a measurements were largely derived from the MCM LTER algal microbial mat biomass core dataset (10.6073/pasta/519bfca4ea3cda94b09edb78ff8759db), and DIN and SRP values were derived from the MCM LTER stream nitrogen and phosphorus core dataset (10.6073/pasta/f6131f5ef67901bc98027e9df55ec364). https://mcm.lternet.edu/sites/default/files/data/mcmlter-strm-kohler-mat_isotopes-20230420.csv STRM_MAT_ISOTOPES eng; US McMurdo Dry Valleys LTER STRM_MAT_ISOTOPES Data Source Definition : Biomass, nutrient ratios, and isotopic signatures of stream microbial mats. Record Delimiter : \n Number of Header Lines : 1 Orientation : Column Quote Character : "Field Delimiter : , false dataset_code Internal dataset code. strmtrnsid MCM LTER stream algal transect ID. stream_name Name of the stream where sample(s) were collected. valley Name of the valley where sample(s) were collected within the McMurdo Dry Valleys region of Antarctica. outlet Outlet of the stream associated with the sample. latitude Stream algal transect latitude. longitude Stream algal transect longitude. mat_type Type of microbial mat sampled (i.e., black, orange, red, or green). replicate Replicate number or identifier associated with the sample collection. In cases where the sample also exists in the microbial biomass core dataset (see provenance notes), this column corresponds with the sample name. date_sampled Date sample(s) were collected. Date Time Format: YYYY-MM-DD season January-year in which the samples were taken. dist_transect Distance from stream algal transect to its source glacier (for samples collected within Taylor Valley only). dist_coast Distance from stream algal transect to the coast of the Ross Sea (for samples collected within Taylor Valley only). d13c_permil Measure of the ratio of 13C:12C in standard delta notation, expressed relative to universal isotope standards (Pee Dee Belemnite) in parts per thousand (per mil). d15n_permil Measure of the ratio of 15N:14N in standard delta notation, expressed relative to universal isotope standards (atmospheric N2) in parts per thousand (per mil). Un-acidified aliquot used. cn_ratio Molar ratio of carbon to nitrogen. cp_ratio Molar ratio of carbon to phosphorus. np_ratio Molar ratio of nitrogen to phosphorus. afdm_mg_cm2 The mass of mat sample lost following ignition per unit area. chla_ug_cm2 Quantity of measured chlorophyll-a pigment per unit area. ai_ratio The ratio of chlorophyll-a to AFDM. din_ug_l Average dissolved inorganic nitrogen (see methods for more details). srp_ug_l Average soluble reactive phosphorus (see methods for more details). DBF https://mcm.lternet.edu/sites/default/files/data/mcmlter-strm-kohler-mat_isotopes-20230420.csv dataset Black, green, red, and orange mats were taken from established transects (descriptions in McKnight et al. 1998; Kohler et al. 2015) from 10 January 2012 to 23 January 2013. For all streams, sampling was executed by lifting mats from substrata with a spatula, and cores were taken with a brass cork borer (#13, 227 mm2). For each mat type, cores were taken for elemental and isotopic composition (C:N:P stoichiometry, and δ13C and δ15N isotopes) and biomass as ash-free dry mass (AFDM) and chlorophyll-a (chla) if sufficient material was available. Samples were dewatered onto Whatman® GF/F filters, wrapped in foil, and frozen at the field camp for later analysis. For samples from Taylor Valley, distances of sites to both its source glacier and the distance to the Ross Sea coast were further approximated with Google Earth©. Biomass (as AFDM and chla) was determined as in Kohler et al. (2015). Briefly, chla was measured by extracting samples in 90% buffered acetone for 24 hours (Welschmeyer 1994) and analyzed on a Turner Designs 10-AU field fluorometer. AFDM subsamples were dried at 55 ºC for 24 h (or until a constant mass was achieved), weighed, burned at 450 ºC for 4 h and reweighed, then rewetted and dried to determine mass loss caused by hydration of sediments (Steinman et al. 1996). An autotrophic index (AI) was created by dividing chla values by their corresponding AFDM. All biomass analyses were performed in Crary Laboratory at McMurdo Station. The C:N:P and isotope subsamples were dried at 50-55 ºC until a stable mass was achieved and ground to a powder. Prior to analysis, carbonates were removed from the C:N aliquot by fumigation (Hedges and Stern 1984) to prevent loss of acid-soluble carbon that may occur with rinsing. A second aliquot was analyzed without acidification to more accurately measure δ15N values, which may slightly increase following fumigation (Harris et al. 2001). Because separate aliquots were used to measure δ13C and δ15N, some samples do not have both isotope measurements. Furthermore, some samples did not have adequate C or N concentrations to make an accurate isotopic measurement, and these fields are designated by blank fields. Percent C and N content was measured using a CE 1500 Elemental Analyzer (CE Instruments Ltd., Wigan, UK) and δ13C and δ15N isotope ratios were obtained with Finnigan-MAT Delta Plus XL mass spectrometer at the Center for Stable Isotope Biogeochemistry operated by the University of California, Berkeley. The %P aliquot was ashed in a muffle furnace at 500 ºC for 1 h, digested with 1N HCl, and analyzed as soluble reactive phosphorus (SRP) with a Lachat QuikChem 8500 Flow Injection Analyzer (Hach Company, Loveland, Colorado) by the Kiowa lab at the University of Colorado (Murphy and Riley 1962). A spinach standard (#1570a) was analyzed every ~10 samples to ensure method accuracy and digestion success. Resulting values were converted to molar C:N, C:P, and N:P ratios. Streamwater chemistry samples were collected opportunistically for each stream throughout the flow season, ranging from 1 to 10 samples for each stream transect per summer, with an average of 4.6 (median = 4.0) samples per stream in 2011-12 and an average of 4.9 (median 5.5) in 2012-13. Raw water for nutrient analyses was collected in triple-rinsed 250 mL Nalgene® bottles, filtered through glass-fiber filters, and frozen at the field station. Stream water nutrient analyses were performed on either a Skalar San++ Continuous Flow Analyzer (2011-2012 summer) or a Lachat QuickChem Flow Injection Analyzer (2012-2013 summer) optimized for low concentrations. Dissolved inorganic nitrogen (DIN) was calculated as the sum of NH4+-N, NO2--N and NO3--N. In general, NH4+-N and NO2--N were mostly low or undetectable. Detection limits for 2011-2012 nutrient data were 1 μg L-1 for NO2--Nand NO3--N, and 3 μg L-1 for P-SRP. For 2012-2013 nutrient data, detection limits were 1 µg L-1 for NO3--N, 0.7 μg L-1 for NO2--N, 5 μg L-1 for NH4+-N, and 0.6 μg L-1 for P-SRP. In cases where the measured concentrations of stream water nutrients were below detection limits, a value of half the respective detection limit was designated. For each transect for each summer an average value for both DIN and SRP was calculated. References Cited: Harris, D., W. R. Horwáth, and C. van Kessel. 2001. Acid fumigation of soils to remove carbonates prior to total organic carbon or carbon-13 isotopic analysis. Soil Science Society of America Journal 65: 1853–1856. Hedges, J.I., and J.H. Stern. 1984. Carbon and nitrogen determinations of carbonate containing solids. Limnol. Oceanogr. 29: 657-663,  doi: 10.4319/lo.1984.29.3.0657 Kohler, T.J., L.F. Stanish, S.W. Crisp, J.C. Koch, D. Liptzin, J.L. Baeseman, and D.M. McKnight. 2015. Life in the main channel: long-term hydrologic control of microbial mat abundance in McMurdo Dry Valley streams, Antarctica. Ecosystems 18: 310-327, doi:10.1007/s10021-014-9829-6 McKnight, D.M., A.S. Alger, C.M. Tate, G. Shupe, and S. Spaulding. 1998. Longitudinal patterns in algal abundance and species distribution in meltwater streams in Taylor Valley, Southern Victoria Land, Antarctica, p. 109–127. In J.C. Priscu, [ed.], Ecosystem Dynamics in a Polar Desert: The McMurdo Dry Valleys, Antarctica, Antarctic Research Series Vol. 72, American Geophysical Union. Murphy, J., and J.P. Riley. 1962. A modified single solution method for determination of phosphate in natural waters. Anal. Chim. Acta. 26: 31-36. Steinman, A., Lamberti, G.A., and Leavitt, P.R. 1996. Biomass and pigments of benthic algae. In Hauer, F.R., and Lamberti, G.A., Eds. Methods in stream ecology. 2nd ed. San Diego, CA: Academic Press, 357-379. Welschmeyer, N.A. 1994. Fluorometric analysis of chlorophyll a in the presence of chlorophyll b and pheopigments, Limnol. Oceanog. 39: 1985–1992. doi: 10.4319/lo.1994.39.8.1985 Metadata Access Constraints: none Metadata Use Constraints: none annually McMurdo Dry Valleys LTER http://mcmlter.org/ pointOfContact