Metadata associated with natural and experimental cryoconite holes studied in the McMurdo Dry Valleys, Antarctica
This work was funded by the United States National Science Foundation Polar Programs Award 1443578: Collaborative Research: Stochasticity and Cyroconite Community Assembly and Function (Principal Investigator: Steve Schmidt). It was conceptualized and put in motion by the late Diana Nemergut, who is greatly missed.
In November, 2016, we collected 90 samples from frozen cryoconite holes in Taylor Valley, Antarctica, by drilling out a core of ice and frozen sediment with a 10-cm diameter SIPRE corer. At the end of that month, we collected supraglacial sediments on Canada Glacier and re-distributed them in shallow depressions we created on that same glacier so they would melt in to create experimental cryoconite holes in-situ. These were resampled monthly for the rest of the season.
Sommers, P., R.S. Fontenele, T. Kringen, S. Kraberger, D.L Porazinska, J.L. Darcy, S.K. Schmidt, & A. Varsani. 2019a. Single-stranded DNA viruses in Antarctic cryoconite holes. Viruses. 11(11):1022.
Sommers, P., D.L. Porazinska, J.L. Darcy, F. Zamora, A.G. Fountain, & S.K. Schmidt. 2019b. Experimental cryoconite holes as natural mesocosms for studying community assembly and environmental transitions. Polar Biology. 42(11):1973.
Sommers, P., J.L. Darcy, D.L. Porazinska, E.M.S. Gendron, A.G. Fountain, F. Zamora, K. Vincent, K.M. Cawley, A. Solon, L. Vimercati, J. Ryder, & S.K. Schmidt. 2019c. Comparison of microbial communities in the sediments and water columns of frozen cryoconite holes in the McMurdo Dry Valleys, Antarctica. Frontiers in Microbiology. 10:65
Darcy, J.L., E.M.S. Gendron, P. Sommers, D.L. Porazinska, & S.K. Schmidt. 2018. Island biogeography of cryoconite hole bacteria in Antarctica’s Taylor Valley and around the world. Frontiers in Ecology and Evolution. 6:180.
DNA sequences for 16S and 18S small subunit of the ribosomal RNA gene are available from the Sequence Read Archive under NCBI SRA database under project PRJNA480849 (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA480849/). Meta-genome enomes of Antarctic viruses are in GenBank under accession numbers MN311489-MN311492 and MN328267-MN328291.
Mapping files and processed OTU tables (97% similarity, unrarefied) from the QIIME pipeline as described in Sommers et al. 2019b-c and are available in this repo, designated for natural holes or experimental holes in the mapping files.
Metadata for the 90 samples of natural cryoconite holes are in the document "Sommers_naturalcryoconite_sediment_90_samples.csv" and metadata for the 15 experimental cryoconite holes are in "Sommers_experimentalcryoconite_sediment_15_samples.csv". Many fewer measurements are available for the experimental hole samples due to their smaller size.
We are working on confirming and correcting measurements of C, N, P, and enzyme stoichiometries for the 90 natural cryoconite hole samples.
During the 2017-18 and 2018-19 research seasons, we created two much larger in-situ experiments on Canada Glacier to test two hypotheses regarding the role of stochasticity in microbial community assembly: low population sizes, and priority effects. The DNA sequencing data from these samples has just been received in the past two months, and analysis is just beginning.