Inter-Valley Soil Comparative Survey of the McMurdo Dry Valleys
Citation
Lee C (2019). Inter-Valley Soil Comparative Survey of the McMurdo Dry Valleys. Version 1.1. SCAR - Microbial Antarctic Resource System. Metadata dataset https://doi.org/10.1038/ismej.2011.170 accessed via GBIF.org on 2019-11-13.Description
Recent applications of molecular genetics to edaphic microbial communities of the McMurdo Dry Valleys and elsewhere have rejected a long-held belief that Antarctic soils contain extremely limited microbial diversity. The Inter-Valley Soil Comparative Survey aims to elucidate the factors shaping these unique microbial communities and their biogeography by integrating molecular genetic approaches with biogeochemical analyses. Although the microbial communities of Dry Valley soils may be complex, there is little doubt that the ecosystem’s food web is relatively simple, and evidence suggests that physicochemical conditions may have the dominant role in shaping microbial communities. To examine this hypothesis, bacterial communities from representative soil samples collected in four geographically disparate Dry Valleys were analyzed using molecular genetic tools, including pyrosequencing of 16S rRNA gene PCR amplicons. Results show that the four communities are structurally and phylogenetically distinct, and possess significantly different levels of diversity. Strikingly, only 2 of 214 phylotypes were found in all four valleys, challenging a widespread assumption that the microbiota of the Dry Valleys is composed of a few cosmopolitan species. Analysis of soil geochemical properties indicated that salt content, alongside altitude and Cu2+, was significantly correlated with differences in microbial communities. Our results indicate that the microbial ecology of Dry Valley soils is highly localized and that physicochemical factors potentially have major roles in shaping the microbiology of ice-free areas of Antarctica. These findings hint at links between Dry Valley glacial geomorphology and microbial ecology, and raise previously unrecognized issues related to environmental management of this unique ecosystem.Sampling Description
Study Extent
See Geographic CoverageSampling
Sampling sites were all located on a south facing, 0–20°slope. An intersection was made by two 50 m transects, with the intersection in the middle being the central sampling point (X or C). Four sampling points around the central point were marked (A–D with A being the southernmost point and the remaining points in an anti-clockwise order, or N, E, S, W). Five scoops of the top 2 cm of soil were collected and homogenized at each identified (1 m2) sampling point after pavement pebbles were removed. Samples were stored in sterile Whirl-Pak (Nasco International, Fort Atkinson, WI, USA) at −20 °C until returned to New Zealand, where they were stored at −80 °C until analysis.Quality Control
454 pyrosquencing flowgrams were denoised using AmpliconNoise, including a SeqNoise step to remove PCR errors and a Perseus step to remove PCR chimeras. See Lee et al 2012 and Dreesens et al 2014 for details.Method steps
- Two MICROBIAL_SEQUENCE_SET description files describing X data sets was uploaded to the IPT. X MIMARKS data files were uploaded to the IPT.
Taxonomic Coverages
Molecular surveys of bacterial (16S rRNA) and fungal (ITS) marker genes
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Bacteriarank: domain
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Fungirank: kingdom
Geographic Coverages
The McMurdo Dry Valleys
Bibliographic Citations
- Dreesens L, Lee CK, Cary SC (2014) The Distribution and Identity of Edaphic Fungi in the McMurdo Dry Valleys. Biology 3: 466–483. doi:10.3390/biology3030466. - 10.3390/biology3030466
Contacts
Charles Leeoriginator
position: Senior Lecturer
University of Waikato
Private Bag 3105
Hamilton
3240
NZ
Telephone: +64 7 838 4241
email: charles.lee@waikato.ac.nz
homepage: http://www.ictar.aq
Charles Lee
metadata author
position: Senior Lecturer
University of Waikato
Private Bag 3105
Hamilton
3240
NZ
Telephone: +64 7 838 4241
email: charles.lee@waikato.ac.nz
homepage: http://www.ictar.aq
Charles Lee
author
position: Research Fellow
International Center for Terrestrial Antarctic Research
Private Bag 3105
Hamilton
3240
NZ
Telephone: +64 7 838 4241
email: cklee@waikato.ac.nz
homepage: http://www.ictar.aq
Craig Cary
principal investigator
position: Professor
International Center for Terrestrial Antarctic Research
Private Bag 3105
Hamilton
3240
NZ
Telephone: +64 7 838 4593
email: caryc@waikato.ac.nz
homepage: http://www.ictar.aq
Charles Lee
administrative point of contact
position: Senior Lecturer
University of Waikato
Private Bag 3105
Hamilton
3240
NZ
Telephone: +64 7 838 4241
email: charles.lee@waikato.ac.nz
homepage: http://www.ictar.aq