Heavy metal hyperaccumulation by plants is a powerful tool in phytoremediation, where plants store heavy metals in large amounts in their aboveground tissue. Plant species in the Plantago genus exhibit this phenomenon, and their commonness in metropolitan centers around the world make them strong candidates for use in cities. Additionally, alteration of soil conditions by these plants can have cascading consequences on their soil microarthropod communities, which are strong bioindicators of soil health. To this end, we investigated the hyperaccumulation ability of two plantain species, Plantago lanceolata (non-native to North America) and Plantago rugelii (native to North America), and their soil microarthropod communities from field-collected specimens in Baltimore, MD, USA, which has an extensively documented legacy of heavy metal contamination. Notably, this is the first study to assess the influence of plant hyperaccumulation on soil microarthropod abundance and diversity using soil health bioindication metrics. First, we found that all sites sampled in Baltimore, MD exceed US governmental soil limits for As and Fe. Second, neither Plantago spp. hyperaccumulates any heavy metal in standard heavy metal screenings, though both species show signs of sequestration of some metals in their roots (i.e., phytoexclusion). Additionally, while native P. rugelii did not hyperaccumulate metals in this study, the relatively high translocation factor (TF or root: shoot) suggests it may have the capacity for it. We also found that soil microarthropod abundance was significantly greater in P. lanceolata rhizospheres (p < 0.05), but bioindication of soil health (acari: collembola) was dependent on a combination of plant species identity and contamination level. Lastly, we found that soil microarthropod diversity was significantly affected by Al and As concentration.

中文翻译：

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城市杂草大蕉 （Plantago spp.） 不会过度积累重金属，也不会保护其土壤微节肢动物群落免受这些金属的侵害


植物的重金属过度积累是植物修复的有力工具，植物在其地上组织中大量储存重金属。车前子属的植物物种表现出这种现象，它们在世界各地的大都市中心的普遍性使它们成为城市使用的有力候选者。此外，这些植物对土壤条件的改变会对其土壤微节肢动物群落产生级联影响，而微节肢动物群落是土壤健康的强大生物指标。为此，我们从美国马里兰州巴尔的摩的野外收集标本中研究了两种车前草物种 Plantago lanceolata （非原产于北美） 和 Plantago rugelii （原产于北美） 及其土壤微节肢动物群落的超积累能力，该标本有广泛记录的重金属污染遗产。值得注意的是，这是第一项使用土壤健康生物指示指标评估植物过度积累对土壤微节肢动物丰度和多样性影响的研究。首先，我们发现在马里兰州巴尔的摩采样的所有地点都超过了美国政府对 As 和 Fe 的土壤限制。其次，在标准的重金属筛选中，车前子属都没有过度积累任何重金属，尽管这两个物种都显示出一些金属在其根中被隔离的迹象（即植物排斥）。此外，虽然天然 P. rugelii 在这项研究中没有过度积累金属，但相对较高的易位因子 （TF 或根：芽） 表明它可能具有这种能力。我们还发现，杉木根际土壤微节肢动物的丰度显著增加 （p < 0.05），但土壤健康的生物指示 （acari： 弹尾虫） 取决于植物物种身份和污染水平的组合。 最后，我们发现土壤微节肢动物多样性受 Al 和 As 浓度的显著影响。