Abstract. Phytoremediation can be a cost-effective method of restoring contaminated soils using plants and associated microorganisms. Most studies follow the impacts of phytoremediation solely across the treatment period and have not explored long-term ecological effects. In 1995, a phytoremediation study was initiated near Fairbanks, Alaska, to determine how the introduction of annual grasses and/or fertilizer would influence degradation of petroleum hydrocarbons (PHCs). After 1 year, grass and/or fertilizer-treated soils showed greater decreases in PHC concentrations compared to untreated plots. The site was then left for 15 years with no active site management. In 2011, we re-examined the site to explore the legacy of phytoremediation on contaminant disappearance, as well as on plant and soil microbial ecology. We found that the recruited vegetation and the current bulk soil microbial community structure and functioning were all heavily influenced by initial phytoremediation treatment. The number of diesel-degrading microorganisms (DDMs) was positively correlated with the percentage cover of vegetation at the site, which was influenced by initial treatment. Even 15 years later, the initial use of fertilizer had significant effects on microbial biomass, community structure, and activity. We conclude that phytoremediation treatment has long-term, legacy effects on the plant community, which, in turn, impact microbial community structure and functioning. It is therefore important to consider phytoremediation strategies that not only influence site remediation rates in the short-term but also prime the site for the restoration of vegetation over the long-term.

中文翻译：

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植物修复对受石油污染的亚北极土壤中植物演替和土壤微生物群落的长期影响


摘要。植物修复是一种利用植物和相关微生物修复污染土壤的经济有效的方法。大多数研究仅跟踪植物修复在整个治疗期间的影响，并没有探讨长期的生态影响。 1995 年，阿拉斯加费尔班克斯附近启动了一项植物修复研究，以确定引入一年生草和/或肥料将如何影响石油碳氢化合物 (PHC) 的降解。一年后，与未处理的地块相比，经过草和/或肥料处理的土壤中 PHC 浓度下降幅度更大。该站点随后被闲置了 15 年，没有进行任何主动的站点管理。 2011 年，我们重新检查了该场地，探索植物修复对污染物消失以及植物和土壤微生物生态的影响。我们发现，补充的植被和当前土壤微生物群落的结构和功能都受到初始植物修复处理的严重影响。柴油降解微生物（DDM）的数量与场地植被覆盖率呈正相关，并受到初始处理的影响。即使 15 年后，肥料的最初使用对微生物生物量、群落结构和活性也产生了显着影响。我们的结论是，植物修复处理对植物群落具有长期的遗留影响，进而影响微生物群落的结构和功能。因此，重要的是要考虑植物修复策略，该策略不仅会影响短期的场地修复率，而且还会为场地的长期植被恢复做好准备。