Drought effect on biocrust resilience: High-speed winds result in crust burial and crust rupture and flaking

Giora J. Kidron, Wang Ying, Abraham Starinsky, Moshe Herzberg

Research output: Contribution to journalArticlepeer-review

26 Scopus citations

Abstract

Once established, biocrusts (known also as biological soil crusts or microbiotic crusts) are thought to be relatively resilient to wind erosion, with crust burial being considered as the main mechanism responsible for crust death. Thus far, to the best of our knowledge, crust flaking and rupture under natural conditions were not reported. We report herein a two-year study during two severe drought years (2010 − 2012) in a dunefield in the Negev Desert during which in addition to crust burial, crust rupture and flaking also took place. As for crust burial, it took place under sand sheets or coppice dunes (mounds). Subsequent removal of the coppice dunes by wind resulted in crust disintegration and erosion of the formerly buried crust and the formation of patches devoid of crusts termed herein ‘erosion cirques’. As for crust flaking and rupture, it is explained by a large change in the properties of the extracellular polymeric substances (EPS) composing the crust. The EPS adherence and viscoelastic properties were monitored using a quartz crystal microbalance with dissipation monitoring (QCD-M) technology. EPS adherence and viscoelastic properties deduced from the QCM-D experiments suggest that crust coherence and elasticity, mediated by the EPS, were affected by droughts. Although crust flaking affected up to 25% of the interdunal surface, it is suggested that with continuous rain shortage, further crust flaking is likely to take place under continuous drought-driven dry surface conditions. This positive feedback mechanism, during which initially eroded crusts trigger additional crust erosion, may have severe consequences on the structure and function of drought-prone ecosystems, and may endanger the stability of dunefields, causing dust storms, triggering dune encroachment and declining air quality.

Original languageEnglish
Pages (from-to)848-859
Number of pages12
JournalScience of the Total Environment
Volume579
DOIs
StatePublished - 1 Feb 2017

Keywords

  • Crust erosion
  • Negev Desert
  • Resilience
  • Vulnerability
  • Wind power

Fingerprint

Dive into the research topics of 'Drought effect on biocrust resilience: High-speed winds result in crust burial and crust rupture and flaking'. Together they form a unique fingerprint.

Cite this