ORCID Profile
0000-0003-0400-3754
Current Organisation
The Ohio State University
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Publisher: American Geophysical Union (AGU)
Date: 03-2019
DOI: 10.1029/2018JG004411
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 10-2021
Publisher: Frontiers Media SA
Date: 27-08-2020
Publisher: Springer Science and Business Media LLC
Date: 13-05-2020
Publisher: Copernicus GmbH
Date: 09-03-2021
Abstract: Abstract. Previous studies have established links between bio ersity and soil geochemistry in the McMurdo Dry Valleys, Antarctica, where environmental gradients are important determinants of soil bio ersity. 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 s les 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.
Publisher: Springer Science and Business Media LLC
Date: 20-03-2020
DOI: 10.1038/S41598-020-61922-2
Abstract: Synthetic fertilizer is a potential source of uranium to natural waters, yet evidence is lacking. We analyzed dissolved uranium concentrations in lakes, reservoirs, and rivers in Ohio, USA during the summer of 2017. All water bodies drain areas of extensive agriculture where phosphate-rich fertilizer is applied. Uranium concentrations ranged from 0.3 to 3.9 µg L −1 , with the lowest concentrations observed in the most offshore Lake Erie s les. These results, especially when placed in the context of previous work on both surface and groundwater, suggest that dissolved uranium concentrations in this water emanating from agricultural lands are higher than background, and uranium should be categorized similarly to nitrate and phosphate in that it originates in part from fertilizer application.
Publisher: Geological Society of America
Date: 08-08-2018
DOI: 10.1130/G45048.1
No related grants have been discovered for Christopher Gardner.