Height-dependent aerodynamic effects of Haloxylon ammodendron configurations on wind erosion suppression over simulated Gobi gravel surfaces

Abstract

Understanding how plant size and planting configuration modify airflow over heterogeneous gravel surfaces is essential for wind erosion control in Gobi environments, yet experimental evidence comparing their aerodynamic effects remains limited. Wind tunnel experiments compared two plant-size groups of Haloxylon ammodendron (0.15 m and 0.30 m in height) and different row configurations under 30% and 60% gravel cover (GC). Under 30% GC, the 0.15 m single-row configuration produced greater aerodynamic roughness enhancement and lower mean sediment transport flux than the corresponding 0.30 m configuration. Its mean flux was also substantially lower than that over the corresponding bare gravel surface. Separate single-plant measurements showed greater reductions in near-surface mean wind speed and higher standard deviations of streamwise velocity fluctuations for the 0.15 m plants than for the 0.30 m plants. Under 60% GC, vegetation-related roughness increases were less consistent across wind speeds and configurations, while vegetation addition further reduced mean sediment transport flux. These results identify the tested 0.15 m single-row configuration as a promising candidate for Gobi wind erosion control, subject to further evaluation of field performance and water requirements.