אסיף מאגר המחקר החקלאי

Inferring the impact of rainfall gradient on biocrusts' developmental stage and thus on soil physical structures in sand dunes

Year:

2014

Source of publication :

Authors :

Volume :

13

Co-Authors:

Zaady, E., Department of Natural Resources, Agricultural Research Organization, Gilat Research Center, Mobile Post Negev 2, 85280, Israel
Katra, I., Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Israel
Yizhaq, H., Department of Solar Energy and Environmental Physics, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Israel, The Dead Sea and Arava Science Center, Tamar Regional Council, Israel
Kinast, S., Department of Solar Energy and Environmental Physics, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Israel
Ashkenazy, Y., Department of Solar Energy and Environmental Physics, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Israel

Facilitators :

Link :

Abstract:

The aims of this study were to investigate the impact of biological soil crusts' (biocrust) developmental stage on soil physical structures in sand dunes under two different rainfall regimes. It was hypothesized that biocrust's developmental stage and function, as affected by the aridity level, may impact soil surface properties, pedogenesis and hydrology. Bio-physiological parameters of the biocrust (polysaccharide, protein and chlorophyll contents) were studied for the determination of its developmental stage. The soil physical surface properties that were measured included the surface breaking pressure and granulometry. Hydrological measurements included the infiltration rate and soil moisture regime in deep layers and structure granulometry. These measurements were taken over two years, in scraped top soil surfaces and in homogeneous sandy dunes, and were compared with natural biocrust surfaces. Higher precipitation at the northern site, with a more advanced developmental stage of the natural biocrust compared to the southern site, has affected the structure granulometry by increasing the cohesive fractions of clay and very-fine silt within the soil surface layer. Higher infiltration rates and soil moisture (%) below the biocrust were obtained with the cyanobacterial crust at the dry southern site. Biocrust controls water infiltration into the soil sub-surface by affecting the surface penetrability. The infiltration controlled by the crust was inversed to the rainfall gradient. The novelty of this study is that by characterizing the bio-physiological parameters of biocrusts as affected by aridity levels, it is possible to imitate climate change scenarios on soil moisture in specific sites. © 2014 Elsevier B.V.

Note:

Related Files :

Related Content

More details

You may also be interested in