Spatial variability in shrub vegetation across dune forms in central Saudi Arabia

Bradley, Andrew V.; Haughan, Alice E.; Al-Dughairi, Ahmed; McLaren, Sue J.

Abstract

In desert dune environments, vegetation may be an indicator of dune stability and rates of sediment transport. As topography and underlying controls of vegetation vary over large spatial areas variations in dune form make scaling up of field research difficult. To mitigate this, and to identify spatial variations in vegetation distributions in a Saudi Arabian sand sea, spectral information from high resolution satellite images was classified to map polygons of shrub vegetation over 360 km2 of well-defined linear dunes, broken linear dunes and dome dune forms. When compared to topographic characteristics of the landscape extracted from a digital elevation model, vegetation densities were often highest on 10 to 20-degree slopes elevated above interdune salt deposits on dune flanks. Spatially this was confined to small areas, and density was not always related to dune form, more to the presence of groundwater which could also encourage vegetation on the tops of some dunes. Field observations identified shrubs of mainly Calligonum genus whose size is related to the amounts of salts, moving sediment and access to the water table that varies within and between dune forms. Shrub vegetation density is likened to surface roughness to better understand sediment movement in this environment.

Citation

Bradley, A. V., Haughan, A. E., Al-Dughairi, A., & McLaren, S. J. (2019). Spatial variability in shrub vegetation across dune forms in central Saudi Arabia. Journal of Arid Environments, 161, 72-84. https://doi.org/10.1016/j.jaridenv.2018.10.003

• Journal Article Type: Article
• Acceptance Date: Oct 26, 2018
• Online Publication Date: Nov 10, 2018
• Publication Date: Feb 1, 2019
• Deposit Date: Nov 6, 2018
• Publicly Available Date: Nov 11, 2019
• Print ISSN: 0140-1963
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 161
• Pages: 72-84
• DOI: https://doi.org/10.1016/j.jaridenv.2018.10.003
• Keywords: Dune form; groundwater; slope; remote sensing; WorldView-2; Wadi Al Rimah
• Public URL: https://nottingham-repository.worktribe.com/output/1230814
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0140196318319499?via%3Dihub
• Contract Date: Nov 6, 2018