DOI: 10.5061/dryad.zw3r228bx
title: Location Location Location: Survival of Antarctic biota requires the best real-estate

description: The origin of terrestrial biota in Antarctica has been debated since the
 discovery of springtails on the first historic voyages to the southern
 continent more than 120 years ago. A plausible explanation for the
 long-term persistence of life requiring ice-free land on continental
 Antarctica has, however, remained elusive. The default glacial eradication
 scenario has dominated because hypotheses to date have failed to provide a
 mechanism for their widespread survival on the continent, particularly
 through the Last Glacial Maximum when geological evidence demonstrates
 that the ice sheet was more extensive than present. Here, we provide
 support for the alternative nunatak refuge hypothesis – that ice-free
 terrain with sufficient relief above the ice sheet provided refuges and
 was a source for terrestrial biota found today. This hypothesis is
 supported here by an increased understanding from the combination of
 biological and geological evidence, and we outline a mechanism for these
 refuges during successive glacial maxima that also provides a source for
 coastal species. Our cross-disciplinary approach provides future
 directions to further test this hypothesis that will lead to new insights
 into the evolution of Antarctic landscapes and how they have shaped the
 biota through a changing climate.
description: <strong>Data collection.</strong> We focussed on
 ice-free terrain represented by 15 currently recognized Antarctic
 Conservation Biodiversity Regions (ACBRs); we do not include South Orkney
 Islands. We compiled all published occurrence records for all springtail
 species considered to be endemic or native from these 15 ACBRs and from
 our own unpublished records. We obtained the ten geothermal sites used in
 the analyses by Fraser et al. from their Table S6. We compiled the
 geochronological data from all known cosmogenic-nuclide data from
 Antarctica (https://www.ice-d.org/) and from publications that were used to scrutinise the datasets. Cosmogenic dating is uniquely suited to Antarctic environments, however, there are problematic samples and locations. We include a selection of cosmogenic datasets to represent sites that clearly (or potentially) delineate Last Glacial Maximum surface elevations, and reject datasets where results are inconclusive due to isotope inheritance or incomplete or inconclusive results. From the included datasets we divided cosmogenic sites into two categories based on the 100 km radius around each site (using the criteria from Fraser et al.): (1) those that showed unequivocal endemism; and (2) those where the provenance was equivocal. Setting these criteria, and using springtails as a proxy, was critical to identifying regions where glacial refuges for the vast majority of biota were most likely to have occurred. 
description: <strong>Full details are in the download file
 "</strong><strong>README_Dataset-SurvivalAntarcticBiota.md"</strong> <strong>Software and file formats used.</strong> All maps were created using the Antarctic GIS package ‘Quantarctica’ (https://www.qgis.org/en/site/about/case_studies/antarctica.html) in QGIS ver. 3.22.7. The ACBRs shown in figure 1 and Supplementary figures S1-S7 are included in an ‘Environmental management’ layer within Quantarctica and colours were chosen to match those used previously. For the land topography of Antarctica we used the shapefiles from ‘Bedmachine’ (downloaded from NSIDC, https://nsidc.org/data/nsidc-0756/versions/2) in QGIS ver. 3.22.7. Each input data file was saved as .csv files and imported individually into QGIS for: (1) all individual springtail occurrences (separated into each species), (2) geothermal sites (separated into large and small), (3) geochronological dated sites (separated into high refuge support, and low refuge support), and (4) eDNA signals of springtails. These data were then used to create figures 1 and 2 in the main manuscript, and for more detailed information in figures S1-S7 in Supplementary material. <strong>Compiled data accessibility.</strong><strong> </strong>The .csv data files we used in QGIS for springtail records, geothermal and geochronological sites shown in figures 1 and 2 and figures S1-S7 are available at the Royal Society's figshare portal. We also include our QGIS file used to generate the supplementary figures (QGIS_suppl_figs.qgz) and the .qlr ‘layer definition file’ (All_layers_definition_QGIS.qlr) exported from QGIS, which can be imported into QGIS with Qantarctica along with Bedmachine, which maintains the symbols and colours we used in our figures.
description: Location Location Location: Survival of Antarctic biota requires the best
 real-estate === Provenance for this README --- * File name:
 README\_Dataset-SurvivalAntarcticBiota.md * Authors: Mark I. Stevens *
 Other contributors: Andrew N. Mackintosh * Date created: 2022-12-11 * Date
 modified: 2023-03-03 Dataset Attribution and Usage --- * Title of Dataset:
 Data for the article "Location Location Location: survival of
 Antarctic biota requires the best real-estate" Manuscript
 DOI:10.1098/rsbl.2022.0590 * Identifier for dataset:
 https://doi/10.5061/dryad.zw3r228bx * Dataset Contributors: Mark I.
 Stevens and Andrew N. Mackintosh #### Suggested Citations: * Dataset
 citation: Stevens MI, Mackintosh AN. 2023 Data for the article
 "Location Location Location: survival of Antarctic biota requires the
 best real-estate". Dryad, Dataset. (doi:10.5061/dryad.zw3r228bx) *
 Corresponding publication: Stevens MI, Mackintosh AN. 2023 Location
 Location Location: survival of Antarctic biota requires the best
 real-estate. Biology Letters. Accepted. (doi:10.1098/rsbl.2022.0590) ####
 Contact Information * Name: Mark I. Stevens * Affiliations: Securing
 Antarctica’s Environmental Future, Earth & Biological Sciences,
 South Australian Museum, SA 5000, Australia; and School of Biological
 Sciences, University of Adelaide, SA 5005, Australia * ORCID ID:
 https://orcid.org/0000-0003-1505-1639 * Email:
 mark.stevens@samuseum.sa.gov.au * Alternate Email:
 mark.stevens@adelaide.edu.au ### Additional Dataset Metadata ####
 Acknowledgements Funding sources: This manuscript was supported in part
 from the Australian Research Council (ARC) funding under the SRIEAS (grant
 agreement no. SR200100005) (Securing Antarctica’s Environmental Future).
 #### Dates and Locations * Dates of data collection: All data compiled
 between March and December 2022 * Geographic locations of data: Antarctica
 (see publication for more details) ### Methodological Information Methods
 of data collection/generation: see manuscript and Supplementary files for
 details ### Data and File Overview #### Table of Contents Folder
 "Supplementary files" contains 2 files which can also be
 accessed through the Royal Society's figshare portal
 **Supplementary\_file.docx** **#figures\_S1-S7.pptx** Folder
 "**compiled data files**" contains 28 data files. Naming of the
 csv files (range from 1-14 KB) containing GPS coordinates (decimal
 degrees) is region\_species where all species names can be obtained from
 [3] and regions are "AP"=Anatrctic Peninsula,
 "DML"=Dronning Maud Land, "EL"=Enderby Land,
 "NVL"=North Victoria Land, "SVL"= South Victoria Land,
 "QML"=Queen Maud Land; files with prefix "geo" refer
 to geothermal sites either as large or small [22]; "eDNA" refers
 to springtail DNA detected [27]; "Cosmogenic sites" are
 separated into high confidence and low confidence (see below and
 Supplementary file). * **QGIS\_suppl\_figs.qgz (1,082 KB)** *
 **All\_layers\_definition\_QGIS.qlr (796 KB)** * **AP\_Abrucei.csv** *
 **AP\_Cantarcticus.csv** * **AP\_Cbadasa.csv** * **AP\_Fantarcticus.csv**
 * **AP\_Ftopo.csv** * **AP\_Fwoyciechowskii.csv** * **AP\_Mcaeca.csv** *
 **AP\_Tmixta.csv** * **DML\_Csverdrupi.csv** * **EL\_Feureka.csv** *
 **NVL\_Ccisantarcticus.csv** * **NVL\_Cterranovus.csv** *
 **NVL\_Fgretae.csv** * **NVL\_Fpropia.csv** * **NVL\_Kklovstadi.csv** *
 **QML\_Asubpolaris.csv** * **QML\_Bsudpolaris.csv** *
 **QML\_Tmediantarctica.csv** * **SVL\_Amonoculata.csv** *
 **SVL\_Cnivicolus.csv** * **SVL\_Ghodgsoni.csv** * **Cosmogenic
 sites\_high.csv** * **Cosmogenic sites\_low.csv** * **eDNA sites.csv** *
 **geoLarge.csv** * **geoSmall.csv** * **Compiled data accessibility.**
 ##### Supplementary files. The two main manuscript figures (figures 1 and
 2) showing all springtail, eDNA, geothermal and geochronological
 (cosmogenic) records are provided as greater fine-detail figures (figures
 S1-S7), to reveal greater resolution of detail in each region. These are
 available here, and also at the Royal Society's figshare portal as
 Supplementary files. The 26 .csv data files containing GPS coordinates
 (decimal degrees) that we used in QGIS are provided. In addition, we
 provide the QGIS project file used to generate the supplementary figures
 (QGIS\_suppl\_figs.qgz). The .qlr ‘layer definition file’
 (All\_layers\_definition\_QGIS.qlr) exported from QGIS, can be imported
 into QGIS with Qantarctica along with Bedmachine
 (https://nsidc.org/data/nsidc-0756/versions/2), which maintains the
 symbols and colours we used in our figures to explore this data further.
 ## Description of the Data Software and file formats used. All maps were
 created using the Antarctic GIS package ‘Quantarctica’
 (https://www.qgis.org/en/site/about/case\_studies/antarctica.html; [24])
 in QGIS ver. 3.22.7 [25]. The Antarctic Conservation Biodiversity Regions
 (ACBRs) [1], shown in figure 1 and Supplementary figures S1-S7 are
 included in an ‘Environmental management’ layer within Quantarctica and
 colours were chosen to match those used previously [1]. For the land
 topography of Antarctica we used the shapefiles from ‘Bedmachine’ [26]
 (downloaded from NSIDC, https://nsidc.org/data/nsidc-0756/versions/2) in
 QGIS ver. 3.22.7. Each input data file was saved as .csv files and
 imported individually into QGIS for: (1) all individual springtail
 occurrences (separated into each species), (2) geothermal sites (separated
 into large and small), (3) geochronological dated sites (separated into
 high refuge support, and low refuge support), and (4) eDNA signals of
 springtails. These data were then used to create figures 1 and 2 in the
 main manuscript, and for more detailed information in figures S1-S7 in
 Supplementary material the project file "QGIS\_suppl\_figs.qgz"
 can be used. ## Sharing/access Information Data collection. We focussed on
 ice-free terrain represented by 15 currently recognized Antarctic
 Conservation Biodiversity Regions (ACBRs) [1]; we do not include South
 Orkney Islands. We compiled all published occurrence records for all
 springtail species considered to be endemic or native from these 15 ACBRs
 [2-21] and from our own unpublished records. We obtained the ten
 geothermal sites used in the analyses by Fraser et al. [22] from their
 Table S6. We compiled the geochronological data from all known
 cosmogenic-nuclide data from Antarctica (https://www.ice-d.org/) and from
 publications which were used to scrutinise the datasets. Cosmogenic dating
 is uniquely suited to Antarctic environments [23], however, there are
 problematic samples and locations. We include a selection of cosmogenic
 datasets to represent sites which clearly (or potentially) delineate Last
 Glacial Maximum surface elevations, and reject datasets where results are
 inconclusive due to isotope inheritance or incomplete or inconclusive
 results. From the included datasets we divided cosmogenic sites into two
 categories based on the 100 km radius around each site (using the criteria
 from Fraser et al. [22]): (1) those that showed unequivocal endemism; and
 (2) those where the provenance was equivocal. Setting these criteria, and
 using springtails as a proxy, was critical to identifying regions where
 glacial refuges for the vast majority of biota were most likely to have
 occurred. All published occurrence records for all springtail species
 considered to be endemic or native listed in the publication references
 list and from our own unpublished records. We obtained ten geothermal
 sites used in the analyses by Fraser et al. [22] from their Table S6, see
 their Supplementary file. Cosmogenic-nuclide data from Antarctica
 (https://www.ice-d.org/) and from publications listed in the publication.
 ### References used in Supplementary material 1. Terauds A, Lee JR. 2016
 Antarctic biogeography revisited: updating the Antarctic Conservation
 Biogeographic Regions. Divers. Distrib. 22, 836–840.
 (doi:10.1111/ddi.12453) 2. Carpenter G. 1902 Aptera: Collembola, Insecta,
 chap 9. The report on the collections of natural history made in the
 Antarctic regions during the voyage of the Southern Cross. British Museum
 (Natural History), London, pp 221–223. 3. Baird HP, Janion-Scheepers C,
 Stevens MI, Leihy RI, Chown SL. 2019 The ecological biogeography of
 indigenous and introduced Antarctic springtails. J. Biogeogr. 46,
 1959–1973. (doi:10.1111/jbi.13639) 4. Bowra GT, Holdgate MW, Tilbrook PJ.
 1966 Biological investigations in Tottanfjella and central
 Heimefrontfjella. Br. Antarct. Surv. Bull. 9, 63–70. 5. Collins GE, Hogg
 ID, Convey P, Barnes AD, McDonald IR. 2019 Spatial and temporal scales
 matter when assessing the species and genetic diversity of springtails
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 (doi:10.3389/fevo.2019.00076) 6. Collins GE, Hogg ID, Convey P, Sancho LG,
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 22293–22302. (doi:10.1073/pnas.20079 25117) 7. Enríquez N, Tejedo P,
 Benayas J, Albertos B, Luciáñez MJ. 2018 Collembola of Barrientos Island,
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 (doi:10.1007/s00300-017-2230-0) 8. Lee KL et al. 2019 Biotic interactions
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 Annales de la Société entomologique de Belgique 45, 260–262. 18. Willem V.
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