Using Mediterranean shrubs for the phytoremediation of a soil impacted by pyritic wastes in Southern Spain: A field experiment

Abstract

This is the author’s version of a work that was accepted for publication in Journal of Environmental Management. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Environmental Management 92.6 (2011): 1584-1590 http://dx.doi.org/10.1016/j.jenvman.2011.01.022Re-vegetation is the main aim of ecological restoration projects, and in Mediterranean environments native plants are desirable to achieve successful restoration. In 1998, the burst of a tailings dam flooded the Guadiamar river valley downstream from Aznalcóllar (Southern Spain) with sludges that contained elevated concentrations of metals and metalloids, polluting soils and waters. A phytoremediation experiment to assess the potential use of native shrub species for the restoration of soils affected by the spillage was performed from 2005 to 2007, with soils divided into two groups: pH < 5 and pH > 5. Four native shrubs (Myrtus communis, Retama sphaerocarpa, Rosmarinus officinalis and Tamarix gallica) were planted and left to grow without intervention. Trace element concentrations in soils and plants, their extractability in soils, transfer factors and plant survival were used to identify the most-interesting species for phytoremediation. Total As was higher in soils with pH < 5. Ammonium sulphate-extractable zinc, copper, cadmium and aluminium concentrations were higher in very-acid soils, but arsenic was extracted more efficiently when soil pH was >5. Unlike As, which was either fixed by Fe oxides or retained as sulphide, the extractable metals showed significant relationships with the corresponding total soil metal concentration and inverse relationships with soil pH. T. gallica, R. officinalis and R. sphaerocarpa survived better in soils with pH > 5, while M. communis had better survival at pH < 5. R. sphaerocarpa showed the highest survival (30%) in all soils. Trace element transfer from soil to harvestable parts was low for all species and elements, and some species may have been able to decrease trace element availability in the soil. Our results suggest that R. sphaerocarpa is an adequate plant species for phytostabilising these soils, although more research is needed to address the self-sustainability of this remediation technique and the associated environmental changesThe authors acknowledge financial support from the Spanish Ministry of Science and Innovation (projects:CTM2007-66401-CO2-02/TECNO and CTM2004-06715-CO2-01) and from the Comunidad de Madrid (project EIADES S2009/AMB-1478

Abandoned metalliferous mines: ecological impacts and potential approaches for reclamation

“…The diversity, abundance and species richness of faunal community containing nematodes were shown by Park et al (2011) to be reduced in soils contaminated with drainage from AMLs. Results of a study by Moreno-Jiménez et al (2011a, 2011b indicated that ecological impacts of AMLs are relatively high with risk, affecting potential receptors as soil micro-organisms, flora and fauna. According to these authors, remedial actions are necessary in AMLs to combat its negative impacts on the ecosystem.…”

Tamarix arboreavar.arboreaandTamarix parviflora: Two species valued for their adaptability to stress conditions

“…In the Mediterranean Basin, where coastal areas are largely affected by human overexploitation, the use of species able to tolerate heavy-metals and other abiotic stresses may represent a low-cost solution for phytoremediation in these harsh environments [10,14]. For example, T. gallica is a widespread species in coastal Mediterranean areas, showing a high adaptability to different environments and a high tolerance to heavy-metal polluted soils [1].…”

Influence of mother plant and scarification agents on seed germination rate and vigor in Retama sphaerocarpa L. (Boissier)

“…Retama sphaerocarpa plays an important role in the restoration of degraded areas, due to its capability to withstand dry environments, the symbiosis between its root system and nitrogen-fixing bacteria, its phytoremediation capabilities, and also its importance in some plant communities of arid and semiarid zones (Benayas et al 2002, Caravaca et al 2003, Moreno-Jiménez et al 2011). The aim of this study was to optimize nursery production of Retama sphaerocarpa (Fabaceae), an important shrub species characterized by a seed coat dormancy hindering germination, and used in the restoration of degraded arid and semi-arid areas.…”

“…Retama sphaerocarpa plays an important role in the restoration of degraded areas, due to its capability to withstand dry environments, the symbiosis between its root system and nitrogen-fixing bacteria, its phytoremediation capabilities, and also its importance in some plant communities of arid and semiarid zones (Benayas et al 2002, Caravaca et al 2003, Moreno-Jiménez et al 2011). …”

“…The seeds have a hard seed coat, measuring approximately 3.5-5 x 5-8 mm (Talavera 1997) and weighting between 90 and 100 mg (Pugnaire et al 2006). The main seed dispersal agent is the wind, although water and sometimes animals are also involved in the dispersal process (Haase et al 2000, Manzano et al 2005, Pugnaire et al 2006.Retama sphaerocarpa plays an important role in the restoration of degraded areas, due to its capability to withstand dry environments, the symbiosis between its root system and nitrogen-fixing bacteria, its phytoremediation capabilities, and also its importance in some plant communities of arid and semiarid zones (Benayas et al 2002, Caravaca et al 2003, Moreno-Jiménez et al 2011). The aim of this study was to optimize nursery production of Retama sphaerocarpa (Fabaceae), an important shrub species characterized by a seed coat dormancy hindering germination, and used in the restoration of degraded arid and semi-arid areas.…”