Preprints
https://doi.org/10.5194/soil-2020-95
https://doi.org/10.5194/soil-2020-95

  28 Dec 2020

28 Dec 2020

Review status: this preprint is currently under review for the journal SOIL.

Assessing soil erosion of forest and cropland sites in wet tropical Africa using 239+240Pu fallout radionuclides

Florian Wilken1,2, Peter Fiener2, Michael Ketterer3, Katrin Meusburger4, Daniel Iragi Muhindo5, Kristof van Oost6, and Sebastian Doetterl1 Florian Wilken et al.
  • 1Department of Environmental Systems Science, Eidgenössische Technische Hochschule Zürich, Zürich, Switzerland
  • 2Institute for Geography, Universität Augsburg, Augsburg, Germany
  • 3Chemistry and Biochemistry, Northern Arizona University, Flagstaff, USA
  • 4Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
  • 5Faculty of Agronomy, Université Catholique de Bukavu, Bukavu, DR Congo
  • 6Earth and Life Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium

Abstract. Due to the rapidly growing population in tropical Africa, a substantial rise in food demand is predicted in upcoming decades, which will result in higher pressure on soil resources. However, there is limited knowledge on soil redistribution dynamics following land conversion to arable land in tropical Africa that is partly caused by challenging local conditions for long-term landscape scale monitoring. In this study, fallout radionuclides 239+240Pu are used to assess soil redistribution along topographic gradients at two cropland sites and at three nearby pristine forest sites located in the DR Congo, Uganda and Rwanda. In the study area, a relatively high 239+240Pu baseline inventory is found (mean forest inventory 41 Bq m−2). Pristine forests show no indication for soil redistribution based on 239+240Pu along topographical gradients. In contrast, soil erosion and sedimentation on cropland reached up to 37 and 40 cm within the last 55 years, respectively. Cropland sites show high intra-slope variability with locations showing severe soil erosion located in direct proximity to sedimentation sites. This study shows the applicability of a valuable method to assess tropical soil redistribution and provides insight on soil degradation rates and patterns in one of the most vulnerable regions of the World.

Florian Wilken et al.

 
Status: open (until 08 Feb 2021)
Status: open (until 08 Feb 2021)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Florian Wilken et al.

Florian Wilken et al.

Viewed

Total article views: 202 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
139 56 7 202 3 7
  • HTML: 139
  • PDF: 56
  • XML: 7
  • Total: 202
  • BibTeX: 3
  • EndNote: 7
Views and downloads (calculated since 28 Dec 2020)
Cumulative views and downloads (calculated since 28 Dec 2020)

Viewed (geographical distribution)

Total article views: 182 (including HTML, PDF, and XML) Thereof 180 with geography defined and 2 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 22 Jan 2021
Download
Short summary
This study demonstrates the usability of fallout radionuclides 239Pu and 240Pu as a tool to assess soil degradation processes in Tropical Africa, which is particularly valuable in regions with limited infrastructure and challenging monitoring conditions for landscape scale soil degradation monitoring. The study shows no indication of soil redistribution in forest sites but substantial soil redistribution in cropland (sedimentation > 40 cm in 55 years) with high variability.