<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Although playing an important role in shaping the environment, the mechanisms responsible for runoff initiation and yield in arid and semiarid regions are not yet fully explored. With infiltration-excess overland flow, known also as Hortonian overland flow (HOF) taking place in these areas, the uppermost surface ‘skin’ plays a cardinal role in runoff initiation and yield. Over large areas, this skin is composed of biocrusts, a variety of autotrophs (principally cyanobacteria, green algae, lichens, mosses) accompanied by heterotrophs (such as fungi, bacteria, archaea), which may largely dictate the infiltration capability of the surface. With most biocrust organisms being capable of excreting extracellular polymeric substances (EPS or exopolymers), and growing evidence pointing to the capability of certain EPS to partially seal the surface, EPS may play a cardinal role in hindering infiltration and triggering HOF. Yet, despite this logic thread, great controversy still exists regarding the main mechanisms responsible for runoff generation (runoff initiation and yield). Elucidation of the possible role played by EPS in runoff generation is the focus of the current review.</p>
</abstract>

Although playing an important role in shaping the environment, the mechanisms responsible for runoff initiation and yield in arid and semiarid regions are not yet fully explored. With infiltration-excess overland flow, known also as Hortonian overland flow (HOF) taking place in these areas, the uppermost surface ‘skin’ plays a cardinal role in runoff initiation and yield. Over large areas, this skin is composed of biocrusts, a variety of autotrophs (principally cyanobacteria, green algae, lichens, mosses) accompanied by heterotrophs (such as fungi, bacteria, archaea), which may largely dictate the infiltration capability of the surface. With most biocrust organisms being capable of excreting extracellular polymeric substances (EPS or exopolymers), and growing evidence pointing to the capability of certain EPS to partially seal the surface, EPS may play a cardinal role in hindering infiltration and triggering HOF. Yet, despite this logic thread, great controversy still exists regarding the main mechanisms responsible for runoff generation (runoff initiation and yield). Elucidation of the possible role played by EPS in runoff generation is the focus of the current review.

The role of biocrust-induced exopolymeric matrix in runoff generation in arid and semiarid zones – a mini review

Journal of Hydrology and Hydromechanics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Although playing an important role in shaping the environment, the mechanisms responsible for runoff initiation and yield in arid and semiarid regions are not...

The role of biocrust-induced exopolymeric matrix in runoff generation in arid and semiarid zones – a mini review

Published Online: Nov 15, 2021

Page range: 360 - 368

Received: Jun 24, 2021

Accepted: Aug 27, 2021

DOI: https://doi.org/10.2478/johh-2021-0028

Keywords
Biological soil crusts, Extracellular polymeric substances, Pore clogging, Hydrophobicity, Infiltration-excess overland flow, Water repellency

© 2021 Giora J. Kidron, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The role of biocrust-induced exopolymeric matrix in runoff generation in arid and semiarid zones – a mini review

Published Online: Nov 15, 2021

Page range: 360 - 368

Received: Jun 24, 2021

Accepted: Aug 27, 2021

DOI: https://doi.org/10.2478/johh-2021-0028

KeywordsBiological soil crusts, Extracellular polymeric substances, Pore clogging, Hydrophobicity, Infiltration-excess overland flow, Water repellency

© 2021 Giora J. Kidron, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Biological soil crusts, Extracellular polymeric substances, Pore clogging, Hydrophobicity, Infiltration-excess overland flow, Water repellency