Effects of Wind-Induced Sand Abrasion on Succulent Plant Communities in the Northern Cape, South Africa.

The vegetation of South Africa’s Northern Cape forms part of the Succulent Karoo biome, a globally significant dryland system characterized by exceptionally high succulent diversity and endemism. During drought periods and because of land-use change, reduced vegetation cover can enhance the frequency and intensity of aeolian activity by facilitating sand transport. This process reinforces wind erosion and increases the susceptibility of the remaining vegetation to mechanical disturbance.

Although succulent species are generally well adapted to arid environments, their responses to intensified aeolian impacts remain insufficiently understood. Increased abrasion, tissue damage, and partial burial caused by sandblasting may impair plant functioning and survival, thereby weaken the stabilizing role of vegetation and promoting positive feedbacks between vegetation loss and soil degradation. Despite the importance of these mechanisms for dryland degradation, the direct effects of aeolian abrasion on succulent vegetation and their contribution to land degradation dynamics are still poorly quantified.

This study investigates the effects of sandblasting on individual succulent plants using controlled wind tunnel experiments. Experimental treatments combined wind speeds ranging from 2 to 12 m s⁻¹ with systematically varied sediment loads, including differences in sand concentration and grain-size composition, to determine damage thresholds and evaluate the effects of repeated sandblasting events. The experimental framework enables a clear separation of aerodynamic and sediment-related controls, reflecting both present-day conditions and plausible future sandstorm scenarios in degraded dryland environments. Plant responses were quantified at the individual scale using high-resolution imaging to document abrasion patterns, tissue degradation, and structural alterations.

The results are expected to provide quantitative insights into the role of aeolian processes in driving vegetation degradation and reinforcing land degradation in the Northern Cape. By linking wind erosion intensity to plant-level damage, this study contributes to a mechanistic understanding of degradation pathways in arid and semi-arid rangelands.