Central Asia (CA) has attracted global attention because of either water scarcity or ecosystem degradation. The Amu Darya Delta (ADD), one of the most important oases in CA, is endowed with valuable wetlands and biological resources that provide good ecosystem services to inhabitants. However, the region has experienced climate warming and large-scale anthropogenic changes since the last century. To assess the influences of anthropogenic interventions on the soil environment in this area, surface soil samples collected from the ADD were analysed for aliphatic hydrocarbon fractions and five heavy metals (HMs; including Cd, Zn, Cu, Ni and V). The results indicated that the n-alkanes extracted from surface soils were composed of homologous series from C14 to C35. Relatively high abundances of short-chain n-alkanes (<n-C21) were observed in cluster 1 samples (mainly from the lakeshore of the Aral Sea), while significantly high abundances of mid-chain (n-C21 to n-C25) and long-chain (n-C26 to n-C32) n-alkanes were found in cluster 3 samples, which were distributed in urban and agricultural drainage areas. In addition, very-long-chain n-alkanes (>n-C33) occurred in most surface soils, which might be a sign of a hot and arid climatic environment. Notably, almost all samples presented a clear even carbon dominance of short-chain n-alkanes, especially for cluster 1, which possibly represented the influence of hydrocarbon contamination and highly saline carbonate environments in addition to bacterial degradation. The biomarker indices and HM enrichment index indicated greater effects of crude oil pollution on cluster 1 (specifically samples 2, 4, 5, 6, 13, 16 and 34) and anthropogenic activities such as traffic emissions and agricultural drainage on cluster 3 samples. The results of this study provide evidence that the n-alkane composition and abundance in surface soils respond sensitively to anthropogenic interventions, arid climate and petroleum hydrocarbon pollution.

由于缺水或生态系统退化，中亚 (CA) 已引起全球关注. 阿姆河三角洲 (ADD) 是加州最重要的绿洲之一，拥有宝贵的湿地和生物资源，可为居民提供良好的生态系统服务。然而，自上个世纪以来，该地区经历了气候变暖和大规模的人为变化。为了评估人为干预对该地区土壤环境的影响，分析了从 ADD 采集的地表土壤样品中的脂肪烃组分和五种重金属（HM；包括 Cd、Zn、Cu、Ni 和 V）。结果表明，从表层土壤中提取的正构烷烃由C14到C35的同源系列组成。在簇 1 样品（主要来自咸海湖岸）中观察到相对高丰度的短链正构烷烃（<n-C21），而在分布在城市和农业流域的第 3 组样品中发现了显着高丰度的中链（n-C21 至 n-C25）和长链（n-C26 至 n-C32）正构烷烃。此外，极长链正构烷烃（>n-C33）存在于大多数地表土壤中，这可能是炎热干旱气候环境的标志。值得注意的是，几乎所有样品都呈现出明显均匀的短链正构烷烃碳优势，特别是对于簇 1，这可能代表了碳氢化合物污染和高盐碳酸盐环境以及细菌降解的影响。生物标志物指数和 HM 富集指数表明原油污染对集群 1 的影响更大（特别是样本 2、4、5、6、13、16 和 34）和人为活动，如交通排放和农业排水等集群 3 样本。这项研究的结果提供了证据，表明表层土壤中的正烷烃组成和丰度对人为干预、干旱气候和石油烃污染敏感。