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

<p>Biocrusts are biological communities that occupy the soil surface, accumulate organic matter and mineral particles and hence strongly affect the properties of the soils they cover. Moreover, by affecting water repellency, biocrusts may cause a preferential infiltration of rainwater, with a high impact on the formation of local water pathways, especially for sand dunes. The aim of this study is to shed light on the connections between water repellency and pH, carbonate and organic matter content in two dune ecosystems with different biocrust types. For this, we used contact angle measurements, gas volumetric carbonate determination and organic matter characterization via FT-IR and TOF-SIMS. In both ecosystems, moss-dominated biocrusts showed higher water repellency and higher amounts of organic matter compared to algal or cyanobacterial biocrusts. Surprisingly, the biocrusts of the two dune systems did not show differences in organic matter composition or organic coatings of the mineral grains. Biocrusts on the more acidic dunes showed a significantly higher level of water repellency as compared to higher carbonate containing dunes. We conclude that the driving factor for the increase in water repellency between cyanobacterial and moss-dominated biocrusts within one study site is the content of organic matter. However, when comparing the different study sites, we found that higher amounts of carbonate reduced biocrust water repellency.</p>
</abstract>

Biocrusts are biological communities that occupy the soil surface, accumulate organic matter and mineral particles and hence strongly affect the properties of the soils they cover. Moreover, by affecting water repellency, biocrusts may cause a preferential infiltration of rainwater, with a high impact on the formation of local water pathways, especially for sand dunes. The aim of this study is to shed light on the connections between water repellency and pH, carbonate and organic matter content in two dune ecosystems with different biocrust types. For this, we used contact angle measurements, gas volumetric carbonate determination and organic matter characterization via FT-IR and TOF-SIMS. In both ecosystems, moss-dominated biocrusts showed higher water repellency and higher amounts of organic matter compared to algal or cyanobacterial biocrusts. Surprisingly, the biocrusts of the two dune systems did not show differences in organic matter composition or organic coatings of the mineral grains. Biocrusts on the more acidic dunes showed a significantly higher level of water repellency as compared to higher carbonate containing dunes. We conclude that the driving factor for the increase in water repellency between cyanobacterial and moss-dominated biocrusts within one study site is the content of organic matter. However, when comparing the different study sites, we found that higher amounts of carbonate reduced biocrust water repellency.

Water repellency decreases with increasing carbonate content and pH for different biocrust types on sand dunes

Sylvie.Drahorad@phys.chemie.uni-giessen.de

Journal of Hydrology and Hydromechanics

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

Biocrusts are biological communities that occupy the soil surface, accumulate organic matter and mineral particles and hence strongly affect the properties of...

Water repellency decreases with increasing carbonate content and pH for different biocrust types on sand dunes

Publié en ligne: 15 nov. 2021

Pages: 369 - 377

Reçu: 30 mars 2021

Accepté: 13 juil. 2021

DOI: https://doi.org/10.2478/johh-2021-0022

Mots clés
Organic matter composition, Surface characteristics, TOF-SIMS, Biocrust, Carbonate content, Water repellency

© 2021 Sylvie Laureen Drahorad et al., published by Sciendo

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

Water repellency decreases with increasing carbonate content and pH for different biocrust types on sand dunes

Publié en ligne: 15 nov. 2021

Pages: 369 - 377

Reçu: 30 mars 2021

Accepté: 13 juil. 2021

DOI: https://doi.org/10.2478/johh-2021-0022

Mots clésOrganic matter composition, Surface characteristics, TOF-SIMS, Biocrust, Carbonate content, Water repellency

© 2021 Sylvie Laureen Drahorad et al., published by Sciendo

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

Mots clés
Organic matter composition, Surface characteristics, TOF-SIMS, Biocrust, Carbonate content, Water repellency