Malarkey, J, Baas, JH, Hope, JA et al. (11 more authors) (2015) The pervasive role of biological cohesion in bedform development. Nature Communications, 6. 6257.
Abstract
Sediment fluxes in aquatic environments are crucially dependent on bedform dynamics. However, sediment-flux predictions rely almost completely on clean-sand studies, despite most environments being composed of mixtures of non-cohesive sands, physically cohesive muds and biologically cohesive extracellular polymeric substances (EPS) generated by microorganisms. EPS associated with surficial biofilms are known to stabilize sediment and increase erosion thresholds. Here we present experimental data showing that the pervasive distribution of low levels of EPS throughout the sediment, rather than the high surficial levels of EPS in biofilms, is the key control on bedform dynamics. The development time for bedforms increases by up to two orders of magnitude for extremely small quantities of pervasively distributed EPS. This effect is far stronger than for physical cohesion, because EPS inhibit sand grains from moving independently. The results highlight that present bedform predictors are overly simplistic, and the associated sediment transport processes require re-assessment for the influence of EPS.
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Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2015 Macmillan Publishers Limited. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Institute for Applied Geosciences (IAG) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 15 Jul 2015 10:01 |
Last Modified: | 20 Mar 2019 15:44 |
Published Version: | http://dx.doi.org/10.1038/ncomms7257 |
Status: | Published |
Publisher: | Nature Publishing Group |
Identification Number: | 10.1038/ncomms7257 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:85759 |
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