吉兰泰盐湖中心盐爪爪灌丛沙堆形态及其沉积特征

为了探究盐湖区盐爪爪灌丛沙堆形态特征和沉积特征,以阿拉善盟吉兰泰盐湖中心盐爪爪灌丛沙堆为研究对象,通过野外调查和室内分析研究了非围封区、围封区灌丛沙堆形态特征和表层沉积物粒度特征。结果表明:(1)研究区盐爪爪灌丛沙堆均处于初级发育阶段,非围封区盐爪爪灌丛沙堆密度远大于围封区。根据独立样本T检验分析,研究区盐爪爪灌丛沙堆高度(H_d)、体积(V)、底面积(A_d)、长轴与短轴之比(L/W)均无显著差异。(2)研究区表层颗粒主要以细砂和极细砂为主,但围封区粒度集中度大于非围封区,同时灌丛沙堆沉积物土壤粒度由迎风坡向背风坡趋于细化,从坡脚到坡顶沙粒趋于细化。(3)沉积物粒度由坡底到坡顶、迎风坡到背风坡平均粒度逐渐减小。灌丛沙堆分选性较差,沉积物粒度主要以细组分为主,沉积物颗粒分布较为集中。因此,研究结果有助于定量分析盐爪爪的固沙阻沙能力,为吉兰泰盐湖区生态系统保护与恢复提供了数据资料。

Morphological and Sedimentary Characteristics of Dune Covered by Kalidium foliatum Nebkhas in the Center of Jilantai Salt Lake

The aim of this study was to explore the morphological and sedimentary characteristics of Kalidium foliatum Nebkhas in salt lake district. The dunes covered by Kalidium foliatum Nebkhas in the Center of Jilantai Salt Lake in Alashanmon, Inner Mongolia, China, was selected as the studied sites, and the investigation on morphological characteristics of and the grain size characteristics of the surface sediments in two land use patterns was carried out by means of correlation analysis and regression analysis. The results showed that:(1) Kalidium foliatum Nebkhas were all at the primary growth stage in two land use patterns;the density of Kalidium foliatum Nebkhas in non-enclosed area was much higher than that in enclosed area;according to independent sample T-test analysis, there was no significant difference in H_d, V, A_d, L/W between the two land use patterns;(2) the grains of surface sediment were mainly fine sand and very fine sand in research area, but the concentration of grain size in the enclosure area was greater than that in the non-enclosed area;at the same time, the grain size of leeward slope of Kalidium foliatum Nebkhas tends to be finer than that in the windward slope, and the grain size tends to be finer from the foot of slope to the top of slope;(3) under two land use patterns, the grain size of surface sediment of Kalidium foliatum Nebkhas gradually decreases from slope bottom to slope top, the average grain size of windward slope was larger than leeward slope, and sorting of grain size was weak in the dune covered by shrub, therefore, the grain size of sediment was mainly composed of coarse components, and the distribution of sediment particles was relatively dispersed. Therefore, the research results are helpful for quantitative analysis of sand fixation ability of Kalidium foliatum, and provide data for ecosystem protection and restoration in Jilantai Salt Lake area.