Universidad Politécnica de Cartagena, Departamento de Ciencia y Tecnología Agraria, Paseo Alfonso XIII, 48-30203 Cartagena, Spain.
Sci Total Environ. 2011 Sep 15;409(20):4470-9. doi: 10.1016/j.scitotenv.2011.07.049. Epub 2011 Aug 17.
The aims of this study were to determine the factors which control metal and As phytoavailability in the different microenvironments (Sand Dunes, Salt Flat, Dry River and Shrubs) present at a Mediterranean salt marsh polluted by mining wastes. We performed a field study following a plot sampling survey. The analyses of soil parameters (pH, electrical conductivity (EC), organic carbon contents, etc.), total metal and As concentrations and their phytoavailability assessed with EDTA were related to each microenvironment and the corresponding plant species uptake. The averages of pH and EC were slightly alkaline (pH ≈ 7.5) and saline (≈ 2.2 to 17.1 dS m(-1)) respectively. The soil samples from the Salt Flat subzone showed the highest metal concentrations (e.g. 51 mg kg(-1) Cd, 11,600 mg kg(-1) Pb) while for As, the highest concentrations occurred in the Dry River (380 mg kg(-1) As). The total metal and EDTA-extractable concentrations occurred as it follows: Salt Flat>Dry River>Degraded Dunes>Shrubs. In relation to plant metal and As accumulation, the highest root concentrations were obtained in the species from the Salt Flat subzone: ~17 mg kg(-1) As, ~620 mg kg(-1) Pb, for both, Juncus maritimus and Arthrocnemum macrostachyum. However the highest metal and As shoot concentrations occurred in species from the Sand Dunes: ~23 mg kg(-1) As ~270 mg kg(-1) Pb for Dittrichia viscosa; ~23 mg kg(-1) As, ~390 mg kg(-1) Zn for Crucianella maritima. The occurrence of edaphic gradients including salinity and texture determined the vegetation distribution. However, it cannot be concluded that there was a disturbance due to metal(loid)s soil concentrations in terms of vegetation composition except in the Degraded Dunes and Dry River. The higher EDTA-extractable concentrations were coincidental with the most saline soils but this did not result in higher metal(loid)s plant accumulation.
本研究旨在确定控制不同微环境（沙丘、盐滩、干河和灌木）中金属和砷植物可利用性的因素，这些微环境存在于受采矿废物污染的地中海盐沼中。我们进行了一项现场研究，采用了一个样本地块调查。土壤参数（pH 值、电导率（EC）、有机碳含量等）、总金属和砷浓度及其用 EDTA 评估的植物可利用性与每个微环境和相应的植物吸收有关。pH 值和 EC 的平均值略呈碱性（pH 值约为 7.5）和咸性（约为 2.2 至 17.1 dS m(-1)）。盐滩亚区的土壤样品显示出最高的金属浓度（例如，Cd 为 51mg kg(-1)，Pb 为 11600mg kg(-1)），而对于砷，干河的浓度最高（380mg kg(-1)As）。总金属和 EDTA 可提取浓度的顺序如下：盐滩>干河>退化沙丘>灌木。关于植物金属和砷的积累，盐滩亚区物种的根浓度最高：17mg kg(-1)As，620mg kg(-1)Pb，Juncmus maritimus 和 Arthrocnemum macrostachyum 均如此。然而，沙丘物种的金属和砷茎浓度最高：23mg kg(-1)As，270mg kg(-1)Pb，Dittrichia viscosa；23mg kg(-1)As，390mg kg(-1)Zn，Crucianella maritima。包括盐分和质地在内的土壤梯度的发生决定了植被的分布。然而，除了退化沙丘和干河外，不能根据土壤金属（类）浓度对植被组成得出存在干扰的结论。较高的 EDTA 可提取浓度与最咸的土壤巧合，但这并没有导致金属（类）植物积累更高。
