uid=MCM,o=EDI,dc=edirepository,dc=org all public read HZSEDS_DIATOMS Joshua Darling joshua.darling@colorado.edu https://orcid.org/0000-0001-9074-4617 Ruth Heindel heindel1@kenyon.edu https://www.ruthcheindel.com/ https://orcid.org/0000-0001-6292-2076 Joel Singley

Institute of Arctic and Alpine Research Boulder CO 80303 US

joel.singley@colorado.edu https://orcid.org/0000-0002-7906-8491 Anna Bergstrom annabergstrom@boisestate.edu https://orcid.org/0000-0002-9684-4018 Diane McKnight diane.mcknight@colorado.edu https://orcid.org/0000-0002-4171-1533 McMurdo Dry Valleys LTER http://mcmlter.org/ Braeden Lukkari Braeden.Lukkari@colorado.edu lab technician Renée Brown rfbrown@unm.edu https://orcid.org/0000-0002-4986-7663 data manager 2021-01-06 English

In this data package, we present diatom community assemblages from hyporheic sediments collected in January 2019 from six transects across Von Guerard Stream, Taylor Valley, Antarctica. These samples were collected to address questions about the retention and processing of particulate organic matter in the hyporheic zone of McMurdo Dry Valley streams. The six transects were located at pools, riffles, and meanders (three of each geomorphology type) along Von Guerard Stream and extended across the stream channel to the edges of the wetted zone, ranging from 6.6 to 13.6 m in length. At each sampling location, we collected subsurface sediment sample that was preserved in formalin directly after sample collection. We characterized diatom assemblages by counting a total of 300 diatom valves from each preserved diatom sample. This data package is associated with a complementary data package that contains hyporheic sediment chemistry for the same samples.

community composition diatoms hyporheic zone sediments LTER Controlled Vocabulary Antarctic desert streams Antarctica hyporheic zone LTER McMurdo Dry Valleys sediment Taylor Valley Station Keywords population dynamics LTER Core Areas

This data package is released under the Creative Commons Attribution 4.0 International License (CC BY 4.0; http://creativecommons.org/licenses/by/4.0/), which allows consumers (hereinafter referred to as “Data Users”) to freely reuse, redistribute, transform, or build on this work (even commercially) so long as appropriate credit is provided. Accordingly, Data Users are required to properly cite this data package in any publications or in the metadata of any derived products that result from its use (in whole or in part). A recommended citation is provided on the summary metadata page associated with this data package in the McMurdo Dry Valleys LTER Data Catalog (https://mcmlter.org/data), and a generic citation may be found on the summary metadata page in the repository where this data package was obtained. When these data contribute significantly to the contents of a publication, Data Users must also acknowledge that data were provided by the NSF-supported McMurdo Dry Valleys Long Term Ecological Research program (OPP-2224760). This data package has been released in the spirit of open scientific collaboration. Hence, Data Users are strongly encouraged to consider consultation, collaboration, and/or co-authorship (as appropriate) with the data package creator(s). Data Users should be aware these data may be actively used by others for ongoing research; thus, coordination may be necessary to prevent duplicate publication. Data Users should also recognize that misinterpretation of data may occur if they are used outside the context of the original study. Hence, Data Users are urged to contact the data package creator(s) if they have any questions regarding methodology or results. While substantial efforts are made to ensure the accuracy of this data package (with all its components), complete accuracy cannot be guaranteed. Periodic updates to this data package may occur, and it is the responsibility of Data Users to check for new versions. This data package is made available “as is” and comes with no warranty of accuracy or fitness for use. The creator(s) of this data package and the repository where these data were obtained shall not be liable for any damages resulting from misinterpretation, use, or misuse of these data. Finally, as a professional courtesy, we kindly request Data Users notify the primary contact referenced in the metadata when these data are used in the production of any derivative work or publication. Notification should include an explanation of how the data were used, along with a digital copy of the derived product(s). Thank you.

https://mcm.lternet.edu/content/hyporheic-diatom-community-assemblages-von-guerard-stream-taylor-valley-mcmurdo-dry-valleys Transect type is "meander." Coordinates provided by Ruth Heindel on 24 September 2020. 163.255683000000 163.255683000000 -77.610933000000 -77.610933000000 Transect type is "meander." Coordinates provided by Ruth Heindel on 24 September 2020. 163.296560000000 163.296560000000 -77.620117000000 -77.620117000000 Transect type is "pool." Coordinates provided by Ruth Heindel on 24 September 2020. 163.282600000000 163.282600000000 -77.618700000000 -77.618700000000 Transect type is "pool." Coordinates provided by Ruth Heindel on 24 September 2020. 163.293367000000 163.293367000000 -77.619867000000 -77.619867000000 Transect type is "riffle." Coordinates provided by Ruth Heindel on 24 September 2020. 163.256000000000 163.256000000000 -77.611083000000 -77.611083000000 Transect type is "riffle." Coordinates provided by Ruth Heindel on 24 September 2020. 163.280733000000 163.280733000000 -77.618467000000 -77.618467000000 2019-01-10 McMurdo Dry Valleys LTER Information Manager im@mcmlter.org McMurdo Dry Valleys LTER http://mcmlter.org/ McMurdo Dry Valleys LTER

Field MethodsDuring January 2019, we collected hyporheic sediments nine transects across pools, meanders, and riffles along Von Guerard Stream in Taylor Valley, Antarctica. Each transect was composed of five sampling sites at different lateral positions across the stream channel: two sampling sites were located at the margins of the visible wetted zone, one sampling site was directly under the thalweg, and two sampling sites were located halfway between the wetted margin and the thalweg. Transects ranged from 6.6 m to 13.6 m in total length across the stream channel. At each sampling site, we removed the surface sediment and mat material in order to focus our sampling on the underlying hyporheic sediments. To characterize the diatom assemblages, we collected a sample in a plastic scintillation vial that was preserved in formalin directly after sample collection. Laboratory AnalysesDiatom assemblages were characterized at six of the nine transects (two transects for pool, meander, and riffle) by counting a total of 300 diatom valves from preserved samples. First, a subset of sediment was transferred to 50 mL centrifuge tubes. We cleaned samples of organic content by digesting with hydrogen peroxide (30 mL of 30% H2O2) for 48 hours at 100ºC. After digestions were complete, samples were repeatedly rinsed with distilled water until a neutral pH was reached. We isolated diatoms from sand grains and other mineral aggregates through repeated resuspension and centrifugation to carefully retain the diatoms in the supernatant. Aliquots of supernatant were dried on coverslips and mounted to glass microscope slides using a highly refractive adhesive (Zrax, W. P. Dailey, Philadelphia, USA). We counted diatoms at 1250x magnification on an Olympus BX50 DIC microscope and identified taxa using descriptions listed in the Antarctic Freshwater Diatoms Database. Fragmented diatom frustules were identified to the highest taxon-level possible (mostly genus level). All relative abundance composition data was standardized to the total number of diatom valves counted per sample.  

Hyporheic zone sediment diatoms HZSEDS_DIATOMS.csv 119887 1 column , " https://mcm.lternet.edu/sites/default/files/data/HZSEDS_DIATOMS_0.csv DATASET_CODE Dataset code Internal dataset code. string Internal dataset code. STREAM Stream name Name of the stream where sample was collected. string Name of the stream where sample was collected. SAMPLE_DATE Sample date Date samples were collected. date MM/DD/YYYY SAMPLE_ID Sample identifier Unique sample identifier that contains the geomorphology type, the transect number, and the lateral position. Sample identifiers are based on location, e.g., P1-3 refers to a sample collected from pool transect number 1 (upper transect) and at position 3 of 5 across the transect. string M meander P pool R riffle TRANSECT Transect identifier Transect identifier. Transects are numbered from north to south. string M meander P pool R riffle GEOMORPH Geomorphic classification Geomorphic classification type of the sample/transect location. string Geomorphic classification type of the sample/transect location. LATERAL_POSITION Lateral position Lateral position of the sample across the transect. string 1 margin of the wetted zone (inside bank for meanders) 2 intermediate 3 stream thalweg 4 intermediate 5 margin of the wetted zone (outside bank for meanders) TAXON_ID Taxon identifier Taxon identifier relates observed species to current (as of August 2020) taxonomy updated to the Antarctic Freshwater Diatoms Database: http://huey.colorado.edu/diatoms/taxa/index.php string Taxon identifier relates observed species to current (as of August 2020) taxonomy updated to the Antarctic Freshwater Diatoms Database: http://huey.colorado.edu/diatoms/taxa/index.php SPECIES Species Genus and specific epithet of species using taxonomy current as of August 2020. string Genus and specific epithet of species using taxonomy current as of August 2020. ABUNDANCE Relative abundance Qualitative, percent relative abundance for each species in each sample. percent real ratio of two quantities as percent composition (1:100)