关键词: 灌丛沙堆, 风蚀, 土地退化, 沃岛

Abstract: Nebkhas commonly distributed in arid and semi-arid areas, are mounds composed of wind-borne sediment that traped by shrubs. Studies on nebkhas morphology, sediment, ecology and process are reviewed since 1980s in this paper. There are many factors (such as arid climate, high wind, sand source, bush form, grazing pressure, land-use histories and geomorphologic setting) controlling the development and growth of nebkhas. Nabkha dune sediments are sandier and better sorted than the interdune sediments; sediments are largely locally derived from nearby areas such as interdunes, and are greatly enriched in available inorganic nutrients. Feedbacks with the bush canopy and materials transited from sand sources are the possible causes of the enrichment. The nebkhas have developed as a consequence of climatic change and anthropogenic stresses on the arid ecosystem and are linked to ecological change within the region, so nebkhas have been regarded as a good indicator of aeolian erosion and land degradation. Nebkhas are extensive distributed in China, but little attention is put to it. The author also brings up his own opinions and further orientations of nebkhas research and looks forward to attracting the domestic attention to nebkhas.

Key words: nebkhas, wind erosion, land degradation, fertile island