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United States Department of Agriculture

Agricultural Research Service

Research Project: SUSTAINABLE AGRO-ECOSYSTEMS THAT CONTROL SOIL EROSION AND ENHANCE THE ENVIRONMENT

Location: Wind Erosion and Water Conservation Research

Title: Dust from southern Africa: rate of emission and biogeochemical properties

Authors
item Bhattachan, Abinash -
item D'Odorica, Paolo -
item Zobeck, Teddy
item Okin, Gregory -
item Dintwe, Kebonye -

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: December 3, 2012
Publication Date: December 7, 2012
Citation: Bhattachan, A., D'Odorica, P., Zobeck, T.M., Okin, G.S., Dintwe, K. 2012. Dust from southern Africa: rate of emission and biogeochemical properties[abstract]. American Geophysical Union. December 3-7, 2012. San Francisco, California.

Technical Abstract: The stabilized linear dunefields in the southern Kalahari show signs of reactivation due to reduced vegetation cover owing to drought and/or overgrazing. It has been demonstrated with a laboratory dust generator that the southern Kalahari soils are good emitters of dust and that large-scale dune reactivation can potentially make the region an important dust source in the relatively low-dust Southern Hemisphere. We show that emergence of the southern Kalahari as a new dust source may affect ocean productivity as the soils are rich in soluble iron and the dust from the southern Kalahari commonly reaches the Southern Ocean. We investigate the biogeochemical properties of the fine fraction of soil from the Kalahari dunes and compare them to those of currently active dust sources such as the Makgadikgadi and Etosha pans as well as other smaller pans in the region. Using field measurements of sediment fluxes and satellite images, we calculate the rates of dust emission from the southern Kalahari under different land cover scenarios. To assess the reversibility of dune reactivation in the southern Kalahari, we investigate the resilience of vegetation by looking at changes in soil nutrients, fine soil fractions, and seed bank in areas affected by intense denudation.

Last Modified: 10/19/2014
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