Species composition and population structure of plant communities on semi-fixed dunes of the Gurbantongut Desert, China.

Abstract

The objective of this study was to investigate species composition, and predict future development of dominant species on semi-fixed sand dunes in the Gurbantongut Desert. Using the plant height, crown area and volume instead of age structure, the growth and development condition of dominant shrub populations were analyzed. The results showed that totally 23 species were observed, of which Chenopodiaceae occurred the most with 6 genera 8 species, followed by Asteraceae with 5 genera 6 species. The vegetation community of Gurbantunggut Desert was characterized by few species, and simple structure. As a dominant species, Haloxylon persicum was distributed mainly on the top of the dunes and was a stable increasing population. However, the number of H. ammodendron was small. Artemisia ordosica, as an exotic species introduced by vegetation restoration after construction, covered mainly in the windward and the top of dunes. The po-pulation of A. ordosica had an increasing age structure with a strongly increasing potential, which has affected local species composition. The populations of Calligonum leucocladum and Ephedra distachya were lack of seedlings and had few saplings, resulting in the declining age structure. Due to the same distribution habitat, C. leucocladum might be replaced by A. ordosica in the future.