干旱区生态环境知识资源中心

We used field investigations, wind tunnel experiments and particle size analyses to examine the impact of reclamation practice such as tillage on aeolian desertification associated with four species that represent different stages of the desertification process in the Otindag Desert: Caragana microphylla, Artemisia frigida, Leymus chinensis, and Stipa grandis P. A. Smirn. Among the four species investigated, our wind tunnel experiments showed that after the surface vegetation and soils were fully disturbed, the aeolian intensity associated with the S. grandis communities was the lowest recorded, whereas that associated with the C. microphylla communities was far higher than that in the other communities. These results indicate that aeolian desertification is more likely to occur in C. microphylla communities. After the ground surface structures were destroyed, there were no significant differences in the aeolian intensities associated with each species, although the sites were in different stages of degradation. The aeolian processes caused no great difference between the soil and transported materials in the < 50 mu m particle size fraction, whereas the proportion of sands (100-250 mu m) was higher in the transported material than in the surface soils, indicating that surface coarsening caused by aeolian processes may result in land degradation in the region. Our wind tunnel experiments showed that, under the influence of reclamation, aeolian processes play a critical role in localized aeolian desertification associated with specific species in the Otindag Desert.