Madejón Paula, Marañón Teodoro, Navarro-Fernández Carmen M, Domínguez María T, Alegre José M, Robinson Brett, Murillo José M
Instituto de Recursos Naturales y Agrobiología de Sevilla, IRNAS, Seville, Spain.
Department of Soil and Physical Sciences, Lincoln University, Lincoln, Canterbury, New Zealand.
PLoS One. 2017 Jun 30;12(6):e0180240. doi: 10.1371/journal.pone.0180240. eCollection 2017.
Soil pollution by trace elements (TEs) from mining and industrial activity is widespread and presents a risk to humans and ecosystems. The use of trees to immobilize TEs (phytostabilization) is a low-cost and effective method of soil remediation. We aimed to determine the chemical composition of leaves and flower buds of Eucalyptus camaldulensis in seven sites along the Guadiamar River valley (SW Spain), an area contaminated by a mine-spill in 1998. E. camaldulensis trees in the spill-affected area and adjacent non affected areas were growing on a variety of soils with pH from 5.6 to 8.1 with low concentration of plant nutrients. The spill affected soils contained up to 1069 mg kg-1 of As and 4086 mg kg-1 of Pb. E. camaldulensis tolerated elevated TE concentrations in soil and, compared to other species growing in the same environment, had low TE concentrations in the aerial portions. Besides tolerance to soil contamination, E. camaldulensis had low bioaccumulation coefficients for soil contaminants. TE concentrations in the aboveground portions were below levels reported to be toxic to plants or ecosystems. Flower buds had even lower TE concentrations than leaves. Despite the relatively low concentration of TEs in leaves they were significantly correlated with the soil extractable (0.01 M CaCl2) Cd, Mn and Zn (but not Cu and Pb). The general features of this tree species: tolerance to impoverished and contaminated soils, fast growth and deep root system, and low transfer of TEs from soil to aboveground organs makes it suitable for phytostabilization of soils contaminated by TEs. In addition, eucalyptus leaves could be used for biomonitoring the soil extractability of Cd, Mn and Zn but not Cu or Pb.
采矿和工业活动产生的微量元素对土壤造成的污染十分普遍，给人类和生态系统带来了风险。利用树木固定微量元素（植物稳定作用）是一种低成本且有效的土壤修复方法。我们旨在确定瓜迪亚马尔河谷（西班牙西南部）沿线七个地点的赤桉树叶和花芽的化学成分，该地区在1998年受到矿渣泄漏的污染。受泄漏影响地区和相邻未受影响地区的赤桉生长在各种土壤上，土壤pH值为5.6至8.1，植物养分浓度较低。受泄漏影响的土壤中砷含量高达1069毫克/千克，铅含量高达4086毫克/千克。赤桉能够耐受土壤中升高的微量元素浓度，与生长在同一环境中的其他物种相比，其地上部分的微量元素浓度较低。除了耐受土壤污染外，赤桉对土壤污染物的生物累积系数也较低。地上部分的微量元素浓度低于对植物或生态系统有毒的报道水平。花芽中的微量元素浓度甚至比叶子还低。尽管叶子中的微量元素浓度相对较低，但它们与土壤可提取（0.01M氯化钙）的镉、锰和锌（但不包括铜和铅）显著相关。这种树种的一般特征：耐受贫瘠和污染土壤、生长迅速且根系发达，以及微量元素从土壤向地上器官的低转移率，使其适合用于对受微量元素污染的土壤进行植物稳定修复。此外，桉树叶可用于生物监测土壤中镉、锰和锌（但不包括铜或铅）的可提取性。
