干旱区生态环境知识资源中心

Mu Us Desert, a region with high aeolian activity, is at extremely high risk of sandy desertification. Using surface soil samples collected from Mu Us Desert of northern China, we evaluated the effects of aeolian processes on nutrient loss from surface soils by employing wind tunnel experiments. The experiments were conducted using free-stream wind velocities of 14, 16, 18 and 22 m/s. Our results showed that the fine particles (< 50 mu m in diameter; 12.28% of all transported materials) carrying large nutrient loadings were exported outside the study area by aeolian processes. After the erodible fine particles were transported away from the soil surfaces at low wind velocity (i.e. 14 m/s), the following relatively high wind velocity (i.e. 22 m/s) did not have any significant effect on nutrient export, because the coefficients of variation for soil organic matter, total phosphorus, total nitrogen and available potassium were usually < 5%. Our experimental results confirmed that aeolian processes result in a large amount of nutrient export, and consequently increase the risk of sandy desertification in arid and semi-arid ecosystems.