Phospholipid fatty acids (PLFAs) have been used to trace bacterial life in extremely carbon-poor soils of the hyperarid Atacama Desert. However, the low abundances of bacteria and, thus, PLFAs increases the risk of contamination by exogenous PLFAs. Here, we assess whether field sampling strategies (super-clean, clean, and regular sampling protocols) have an effect on PLFA diversity and abundance in hyperarid Atacama soils or whether laboratory processing or true environmental heterogeneity control PLFA inventories. Our results show no exogenous PLFA contribution during sample processing in the lab and statistical analyses (ANOVA, Kruskal-Wallis) reveal that PLFA abundances do not differ significantly between replicate samples (n = 3) taken with the three different sampling strategies. Rather than sampling strategy, our results show that PLFA abundances in the investigated soil replicates rather reflect true environmental heterogeneity of primarily bacterial biomass (in the absence of indigenous fungi), potentially related to small-scale physicochemical differences.

磷脂脂肪酸（PLFA）已被用来追踪超干旱阿塔卡马沙漠中碳含量极低的土壤中的细菌生活。但是，细菌含量低，因此PLFA会增加外源PLFA污染的风险。在这里，我们评估现场采样策略（超清洁，清洁和常规采样协议）是否对超干旱阿塔卡马土壤中的PLFA多样性和丰度有影响，或者实验室处理或真正的环境异质性控制PLFA清单。我们的结果表明，实验室中的样品处理过程中没有外源PLFA贡献，而统计分析（ANOVA，Kruskal-Wallis）表明，使用三种不同的采样策略采集的重复样品（n = 3）之间的PLFA丰度没有显着差异。与其采用抽样策略，