Zhan Xiu-Li, Xu Yi-Xin, Wang Hong, Gao Ying, Han Lei
School of Geography and Planning, Ningxia University, Yinchuan 750021, China.
College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China.
Ying Yong Sheng Tai Xue Bao. 2021 Sep;32(9):3195-3203. doi: 10.13287/j.1001-9332.202109.030.
As sand dunes gradually become fixed, soil particle size, soil organic carbon (SOC) and total nitrogen (TN) contents vary across different locations of the dunes. To investigate the spatial variation of soil particle size distribution and soil nutrition in the fixed sand dunes, we examined particle composition, SOC and TC features in different locations of dunes in the Eastern Ningxia. The results showed that the particle sizes of each soil layer were mainly characterized by medium and coarse sands. The SOC and TN contents were higher in surface soil layers, with a maximum of 5.781 and 0.412 g·kg, respectively, which were observed in interdune lands and dune ridges, while the leeward slope of the dunes showed the least. The SOC content of both the leeward and windward slope gradually decreased with increasing soil depth along the dune. By contrast, that of the interdune lands decreased first and then increased. At small scale, both the SOC and TN contents showed a clear spatial heterogeneity. There was a positive correlation between soil nutrition contents (SOC and TN) and silt and very fine sand contents in the fixed sand dunes, and a negative correlation with medium and coarse sand contents. Our results implied that soil particle size composition influenced SOC and TN contents. The contents of soil nutrition increased with increa-sing contribution of fine particles, highlighting the role of fine particles in adhesion and accumulation of organic matter.
随着沙丘逐渐固定，土壤颗粒大小、土壤有机碳（SOC）和总氮（TN）含量在沙丘的不同位置存在差异。为了研究固定沙丘中土壤颗粒大小分布和土壤养分的空间变化，我们调查了宁夏东部沙丘不同位置的颗粒组成、SOC和总碳（TC）特征。结果表明，各土层的颗粒大小主要以中砂和粗砂为主。表层土壤层的SOC和TN含量较高，在丘间地和沙丘脊处分别达到最大值5.781和0.412 g·kg，而沙丘背风坡的含量最低。沙丘背风坡和迎风坡的SOC含量均随土壤深度沿沙丘增加而逐渐降低。相比之下，丘间地的SOC含量先降低后增加。在小尺度上，SOC和TN含量均表现出明显的空间异质性。固定沙丘中土壤养分含量（SOC和TN）与粉砂和极细砂含量呈正相关，与中砂和粗砂含量呈负相关。我们的结果表明，土壤颗粒大小组成影响SOC和TN含量。土壤养分含量随着细颗粒贡献的增加而增加，突出了细颗粒在有机质吸附和积累中的作用。
