In:
Biogeosciences, Copernicus GmbH, Vol. 18, No. 5 ( 2021-03-09), p. 1629-1644
Abstract:
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), its central part (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 and/or ice), the lower zone likely represents the most
favorable ecological habitats. Given the strong dependence of geochemistry
on geographic parameters, we developed 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 random forest model predictions was moderately high with
R2 values for total water-soluble salts, water-soluble N:P,
ClO4-, and ClO3- of 0.81, 0.88, 0.78, and 0.74,
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.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-18-1629-2021
DOI:
10.5194/bg-18-1629-2021-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2021
detail.hit.zdb_id:
2158181-2
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