The effect of sparse vegetation on the transport of dune sand by wind

Abstract

The precise effect of a sparse plant cover on the transport of dune sand by wind is a critical factor in understanding the morphology, evolution and global distribution of aeolian dunes^1–3. It is also of considerable practical importance in sand stabilization, rehabilitation and restoration ecology. Here I report the first detailed experimental quantification of this effect using living plants in patterns approximating natural vegetation. For wind velocities V (at 0.5 m elevation) up to 15 m s⁻¹ and plant coverCup to 17%, the rate of aeolian sand transport, q g cm⁻¹ s⁻¹, is closely approximated by q =B[V(1–kC)–V_t]³, where B is Bagnold's constant⁴, V_t is a threshold velocity, and k is a constant dependent on plant geometry. For typical small erect or spreading herbaceous dune plants, k =0.018; for small rounded stemless plants k =0.046.