College of Resources and Environment, Baotou Teachers' College, Baotou, China.
PLoS One. 2022 Aug 5;17(8):e0271562. doi: 10.1371/journal.pone.0271562. eCollection 2022.
Soil water soluble base ion salt-based ion concentrations are critical parameters for estimating soil buffer capacity and vegetation productivity. Ionic content clearly covaries with the distribution of plant communities. Previous studies on salt-based ions in soils focused primarily on ion migration and its relationships with vegetation growth. Few studies have sought to characterize larger scale spatial distribution of salt-based ions or correlation with climatic and plant community characteristics. This study used ion chromatography to analyze the salt-based ion content (Ca2+, Mg2+, Na+ and K+) of surface soils from the Hunshandake sandy lands. Statistical methods were used interpret spatial variation. Results showed that the average content of salt-based ions in Hunshandake sandy land was 86.57 mg/kg. Average values ranked as Ca2+ > Na+ > K+ > Mg2+ but concentrations also exhibited uneven spatial distributions. Horizontal spatial variation in Ca2+, Mg2+ and Na+ ions showed these ions gradually decrease from northwest to southeast. Potassium ions (K+) showed no obvious spatial variation trends. Ions varied significantly across different soil layers but their average concentrations ranked as K+>Na+>Ca2+>Mg2+ (from shallow to deep). The 20-30 cm soil layer contained the highest salt ion concentrations. Of the four base ions, only K+ ions appeared in surface samples. In terms of water soluble base ion available salt-based ions, Ca2+ occurred in the highest concentrations along the north and west side of the study area. K+ ions occurred in the highest concentrations along the south and east sides of the study area. Na+ concentrations did not show a consistent spatial pattern. Statistical analysis detected significant correlations of normalized ion concentration parameters (Ca2+/CECT, K+/CEC, effective water soluble base ion salt-based ions) and the total species number, average species number and total biomass of the plant communities (P <0.05). This study can help inform understanding of soil water transport in sandy areas and provide a reference for interpreting ecosystems in arid regions.
土壤水溶性碱基离子盐基离子浓度是估算土壤缓冲能力和植被生产力的关键参数。离子含量显然与植物群落的分布密切相关。先前关于土壤中盐基离子的研究主要集中在离子迁移及其与植被生长的关系上。很少有研究试图描述盐基离子在更大空间尺度上的分布情况或与气候和植物群落特征的相关性。本研究使用离子色谱法分析了浑善达克沙地表层土壤的盐基离子含量（Ca2+、Mg2+、Na+和 K+）。使用统计方法解释空间变化。结果表明，浑善达克沙地盐基离子的平均含量为 86.57mg/kg。平均含量排序为 Ca2+＞Na+＞K+＞Mg2+，但浓度也表现出不均匀的空间分布。Ca2+、Mg2+和 Na+离子的水平空间变化表明，这些离子从西北向东南逐渐减少。K+离子（K+）没有明显的空间变化趋势。不同土壤层之间的离子差异显著，但平均浓度排序为 K+＞Na+＞Ca2+＞Mg2+（从浅到深）。20-30cm 土壤层含有最高的盐离子浓度。在四种碱基离子中，只有 K+离子出现在表层样品中。就水溶性碱基离子有效盐基离子而言，Ca2+在研究区的北部和西部含量最高。K+离子在研究区的南部和东部含量最高。Na+浓度没有表现出一致的空间模式。统计分析检测到归一化离子浓度参数（Ca2+/CECT、K+/CEC、有效水溶性碱基离子盐基离子）与植物群落的总物种数、平均物种数和总生物量之间存在显著相关性（P<0.05）。本研究可以帮助人们了解沙区土壤水分运移情况，并为干旱地区生态系统的解释提供参考。
