Water-soluble salt and nutrient concentrations of soils collected along the Shackleton Glacier, Antarctica show distinct geochemical gradients related to latitude, longitude, elevation, soil moisture, and distance from coast and glacier. Machine learning algorithms were used to estimate geochemical gradients for the region given the relationship with geography. Geography and surface exposure age drive salt and nutrient abundances, influencing invertebrate habitat suitability and biogeography.
Water-soluble salt and nutrient concentrations of soils collected along the Shackleton Glacier,...
Review status: a revised version of this preprint was accepted for the journal BG and is expected to appear here in due course.
Geochemical zones and environmental gradients for soils from the Central Transantarctic Mountains, Antarctica
Melisa A. Diaz1,2,Christopher B. Gardner1,2,Susan A. Welch1,2,W. Andrew Jackson3,Byron J. Adams4,Diana H. Wall5,Ian D. Hogg6,7,Noah Fierer8,and W. Berry Lyons1,2Melisa A. Diaz et al.Melisa A. Diaz1,2,Christopher B. Gardner1,2,Susan A. Welch1,2,W. Andrew Jackson3,Byron J. Adams4,Diana H. Wall5,Ian D. Hogg6,7,Noah Fierer8,and W. Berry Lyons1,2
1School of Earth Sciences, The Ohio State University, Columbus, OH, USA
2Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH, USA
3Department of Civil, Environmental, & Construction Engineering, Texas Tech University, Lubbock, TX, USA
4Department of Biology, Evolutionary Ecology Laboratories, and Monte L. Bean Museum, Brigham Young University, Provo, UT, USA
5Department of Biology and School of Global Environmental Sustainability, Colorado State University, Fort Collins, CO, USA
6Canadian High Arctic Research Station, Polar Knowledge Canada, Cambridge Bay, Nunavut, Canada
7School of Science, University of Waikato, Hamilton, New Zealand
8Department of Ecology and Evolutionary Biology and Cooperative Institute for Research in Environmental Science, University of Colorado Boulder, Boulder, CO, USA
1School of Earth Sciences, The Ohio State University, Columbus, OH, USA
2Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH, USA
3Department of Civil, Environmental, & Construction Engineering, Texas Tech University, Lubbock, TX, USA
4Department of Biology, Evolutionary Ecology Laboratories, and Monte L. Bean Museum, Brigham Young University, Provo, UT, USA
5Department of Biology and School of Global Environmental Sustainability, Colorado State University, Fort Collins, CO, USA
6Canadian High Arctic Research Station, Polar Knowledge Canada, Cambridge Bay, Nunavut, Canada
7School of Science, University of Waikato, Hamilton, New Zealand
8Department of Ecology and Evolutionary Biology and Cooperative Institute for Research in Environmental Science, University of Colorado Boulder, Boulder, CO, USA
Received: 20 Aug 2020 – Accepted for review: 15 Sep 2020 – Discussion started: 17 Sep 2020
Abstract. Previous studies have established links between biodiversity and soil geochemistry in the McMurdo Dry Valleys, Antarctica, where environmental gradients are important determinants of soil biodiversity. However, these gradients are not well established in the Central Transantarctic Mountains, which are thought to represent some of the least hospitable Antarctic soils. We analyzed 220 samples from 11 ice-free areas along the Shackleton Glacier (~ 85 °S), a major outlet glacier of the East Antarctic Ice Sheet. We established three zones of distinct geochemical gradients near the head of the glacier (upper), central (middle), and at the mouth (lower). The upper zone had the highest water-soluble salt concentrations with total salt concentrations exceeding 80,000 µg g-1, while the lower zone had the lowest water-soluble N : P ratios, suggesting that, in addition to other parameters (such as proximity to water/ice), the lower zone likely represents the most favorable ecological habitats. Given the strong dependence of geochemistry with geographic parameters, we established multiple linear regression and random forest models to predict soil geochemical trends given latitude, longitude, elevation, distance from the coast, distance from the glacier, and soil moisture (variables which can be inferred from remote measurements). Confidence in our model predictions was moderately high, with R2 values for total water-soluble salts, water-soluble N : P, ClO4-, and ClO3- of 0.51, 0.42, 0.40, and 0.28, respectively. These modeling results can be used to predict geochemical gradients and estimate salt concentrations for other Transantarctic Mountain soils, information that can ultimately be used to better predict distributions of soil biota in this remote region.
Water-soluble salt and nutrient concentrations of soils collected along the Shackleton Glacier, Antarctica show distinct geochemical gradients related to latitude, longitude, elevation, soil moisture, and distance from coast and glacier. Machine learning algorithms were used to estimate geochemical gradients for the region given the relationship with geography. Geography and surface exposure age drive salt and nutrient abundances, influencing invertebrate habitat suitability and biogeography.
Water-soluble salt and nutrient concentrations of soils collected along the Shackleton Glacier,...