内蒙毛乌素砂区中东部固定砂丘土壤的发生发育及其利用

毛乌素砂区位于我国内蒙伊克昭盟南部、陕西北部和宁夏河东地区。研究地区属毛乌素砂区中东部,为干草原淡栗钙土亚地带。经两年来的调查,发现该砂区中东部固定砂丘成土条件的植被因素较复杂,除砂生植物外,还夹有草本成分,个别砂丘全部生长针叶灌丛——臭栢。由于风积和风蚀频繁,砂丘上的土壤不易保存完整的剖面。因此,土壤形成中的时间因素也就起着明显的作用。

THE GENESIS AND DEVELOPMENT OF STABILIZED SAND DUNE SOILS IN CENTRAL EASTERN PART OF THE MOYUSU DESERT OF THE ORDOS PLATEAU

The present paper is dealing with genesis and development of the stabilized sand dune soils of the surveyed area. Fixed sand dunes are particularly widespread in the Moyusu Desert region of the Ordos Plateau. They are luxuriantly covered with natural vegetation of psammophyte, such as Artenzisia ordosica and Caragana microphylla Var. tonzentosrz. A great deal of zonal vegetation such as Aster alticus, Pennisetum flaccidum and Lespedeza dahurica occurs as praticipant on the dunes. In addition to the psammpohyte, even Junipenus sabina formation, as scrubs creeping on the dunes, also occupies a considerable area of the dunes. Field observation and laboratory studies show the following genetic properties of the sandy soils. There are few perfect developed profiles, the surface layer has alternatly been modified by wind erosion or sand burying. Although there is no differentiation between the humus horizon and calcium carbonate layer, however, on the well-drained stabilized sand dunes have, more or less, a profile development with A and AB horizons, sometimes, even an incipient development of calcium carbonate horizen. Whereas, looking over the profile of the soils underJuniperus sabina formation one cannot help being struck by the fact that there are A₀₀ and A₀ horizons, underlying the A₀₀ layer lichen and moss are widespread.