干旱区生态环境知识资源中心

The form response of a plant to airflow is a critical factor influencing plant resistance to strong winds and thus the effectiveness of vegetation in reducing wind erosion. As this response is determined by the morphology of the plant and is different in different plant species, the responses of two morphologically different plants to airflow were investigated in wind tunnel experiments. The aerodynamic characteristics of frontal area (FA), optical porosity (OP), frontal area efficiency (FA(eff)) and wind drag force (F-D) in a range of wind velocities were determined for narrow-leafed Cosmos bipinnatus and broad-leafed Ligustrum lucidum Ait. FA and OP reflect a plant’s ability to absorb momentum and allow throughflow, and changes in both measures are linked to wind velocity. In higher wind velocities, FA and OP of both plant types decreased, although L. lucidum lost less frontal area and more porosity than C. bipinnatus. E values (a reconfiguration measure of changes in form) were greater and FD values were less for C. bipinnatus than for L. lucidum. As broad-leafed L. lucidum provided a greater resistance to strong winds than C. bipinnatus, investigating the aerodynamic properties of suitable broad-leafed plants for erosion control in arid lands is recommended.