沙质草原灌丛沙堆研究综述

灌丛沙堆是干旱、半干旱及半湿润荒漠地区风沙流遇到灌丛阻拦而堆积形成的一种地貌形态。普遍的研究表明灌丛沙堆是伴随人类不合理的土地利用和环境的变化而出现,是土壤风蚀和土地退化的标志,也是沙漠化的一种表现形式。灌丛沙堆在我国分布范围很广,但目前研究还不够深入。笔者主要阐述了国内外对灌丛沙堆形态、沉积物、演变及其环境意义等几个方面研究所取得的进展及其存在的争议,并提出了灌丛沙堆研究的发展趋势,以期引起国内对灌丛沙堆研究的关注。

Studies on Sandy Grassland Nebkhas-A Review

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.