Tyler J. KohlerDiane M. McKnight 2023-04-20 tabular digitial data McMurdo Dry Valleys LTER McMurdo Dry Valleys LTER 10.6073/pasta/b217f5f36d18d149a8f52f17a7823f1d https://mcm.lternet.edu/content/biomass-stoichiometry-and-isotopic-signatures-stream-microbial-mats-mcmurdo-dry-valleys 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. 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). 2012-01-10 2013-01-23 ground condition As needed 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 -77.622917175293 -77.622985839844 78m 78m meter 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 -77.643013000488 -77.643096923828 86m 86m meter 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 -77.613243103027 -77.613395690918 54m 54m meter 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 -77.614593505859 -77.614814758301 24m 24m meter 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 -77.634208679199 -77.634559631348 172m 172m meter 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 -77.619300842285 -77.619659423828 89m 89m meter 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 -77.652854919434 -77.653213500977 256m 256m meter 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 -77.625495910645 -77.625877380371 33m 33m meter 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 -77.623992919922 -77.624420166016 30m 30m meter 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 -77.623100280762 -77.623336791992 30m 30m meter 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 -77.601676940918 -77.602165222168 42m 42m meter 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 -77.609222412109 -77.609474182129 24m 24m meter 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 -77.696228027344 -77.696861267090 76m 76m meter 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 -77.720359802246 -77.720619201660 83m 83m meter 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 -77.696968078613 -77.697700500488 185m 185m meter 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 -77.644943237305 -77.645057678223 79m 79m meter LTER Core Areas inorganic nutrients primary production 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 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 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.1984.29.3.0657Kohler, 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/s10021-014-9829-6McKnight, 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 unknown STRM_MAT_ISOTOPES Biomass, nutrient ratios, and isotopic signatures of stream microbial mats. Dataset Code Internal dataset code. The data provider Internal dataset code. Stream Transect ID MCM LTER stream algal transect ID. The data provider MCM LTER stream algal transect ID. Stream Name Name of the stream where sample(s) were collected. The data provider Name of the stream where sample(s) were collected. Valley Name Name of the valley where sample(s) were collected within the McMurdo Dry Valleys region of Antarctica. The data provider 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. The data provider Outlet of the stream associated with the sample. Latitude Stream algal transect latitude. The data provider decimalDegrees Longitude Stream algal transect longitude. The data provider decimalDegrees Mat Type Type of microbial mat sampled (i.e., black, orange, red, or green). The data provider Type of microbial mat sampled (i.e., black, orange, red, or green). Replicate ID 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. The data provider 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. The data provider calendar date/time YYYY-MM-DD gregorian calendar Field Season January-year in which the samples were taken. The data provider January-year in which the samples were taken. Transect Distance Distance from stream algal transect to its source glacier (for samples collected within Taylor Valley only). The data provider kilometer Coast Distance Distance from stream algal transect to the coast of the Ross Sea (for samples collected within Taylor Valley only). The data provider kilometer d13C 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). The data provider perMil d15N 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. The data provider perMil C:N Molar ratio of carbon to nitrogen. The data provider Molar ratio of carbon to nitrogen. C:P Molar ratio of carbon to phosphorus. The data provider Molar ratio of carbon to phosphorus. N:P Molar ratio of nitrogen to phosphorus. The data provider Molar ratio of nitrogen to phosphorus. Ash-free Dry Mass The mass of mat sample lost following ignition per unit area. The data provider milligramsPerCentimeterSquared Chlorophyll-a Quantity of measured chlorophyll-a pigment per unit area. The data provider microgramsPerCentimeterSquared Autotrophic Index The ratio of chlorophyll-a to AFDM. The data provider The ratio of chlorophyll-a to AFDM. Dissolved Inorganic Nitrogen Average dissolved inorganic nitrogen (see methods for more details). The data provider microgramsPerLiter Soluble Reactive Phosphorus Average soluble reactive phosphorus (see methods for more details). The data provider microgramsPerLiter McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-strm-kohler-mat_isotopes-20230420.csv None 2023-04-20 2023-04-20 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