Journal article
Pore characteristics in biological soil crusts are independent of extracellular polymeric substances



Publication Details
Authors:
Felde, V.; Rossi, F.; Colesie, C.; Uteau-Puschmann, D.; Horn, R.; Felix-Henningsen, P.; De Philippis, R.; Peth, S.
Publisher:
PERGAMON-ELSEVIER SCIENCE LTD
Publication year:
2016
Journal:
Soil Biology and Biochemistry
Pages range:
294-299
Volume number:
103
Start page:
294
End page:
299
Number of pages:
6
ISSN:
0038-0717

Abstract
Biological soil crusts (biocrusts) are considered key players in hydrological cycles of many arid environments. The phototrophic organisms in these crusts excrete extracellular polymeric substances (EPSs), which bind soil particles together, thereby stabilizing the soil surface. In a previous work, the non-invasive extraction of EPSs in biocrusts resulted in a change of their hydrological behavior. As this was suspected to be the effect of a change in their pore structure, we employed high resolution X-ray micro tomography to investigate structural changes of biocrusts after EPS-extraction. We studied biocrusts from four different study sites in Svalbard, Germany, Israel and South Africa. Two different fractions of EPSs (tightly bound and colloidal) were extracted, using the same extraction method with two different solvents. Our results suggest that the extraction of EPSs did not result in structural differences at a resolution of 7 mu m. We therefore conclude that the previously observed change in hydrological behavior is likely to be the result of a change of the physico-chemical properties of the very surface of the crust, rather than of its inner structure. (C) 2016 Elsevier Ltd. All rights reserved.


Keywords
Biocrusts, Computed tomography, Ecological restoration, Extracellular polymeric substances, Hydrological cycles, Soil structure

Last updated on 2019-24-01 at 11:02