The importance of pioneer plant species succession and edaphic niches for the phytomanagement of mining impacted ecosystems

Isabel Párraga-Aguado1, María del Carmen Tercero-Gómez1, José Álvarez-Rogel1, María Nazaret González-Alcaraz2, Francisco José Jiménez-Cárceles3, Rainer Schulin4, Héctor Miguel Conesa-Alcaraz1
1 Departamento de Ciencia y Tecnología Agraria, Universidad Politécnica de Cartagena, Spain
2 Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, Amsterdam, Netherlands
3 TECOMA Ingeniería y Ambiente S.L., Murcia, Spain
4 Soil Protection Group, ETH Zürich, Zürich, Switzerland

O 12.5 in Restoration and rehabilitation of ecosystems

17.07.2014, 12:20-12:40, H19

The goal of this work was to identify plant-favourable edaphic niches in mine tailings from a semiarid area in South East Spain, in order to obtain relevant information for further phytomanagement procedures. For this purpose, a transect-designed soil sampling from non-disturbed areas to mine tailings was performed. In addition, a seasonal sampling of ecological indexes (species inventory, richness, diversity and equitability) was performed during three years.

A PCA revealed that plant distribution at the tailings was mainly driven by salinity, while metal(loid)s concentrations played a minor role. The presence of soil desiccation cracks generated low salinity spots which provided favourable niches for the establishment of pioneer vegetation. A significant improvement in fertility conditions (organic matter, microbiology) was found in patches of dense vegetation (‘fertility islands’).

Plant ecological indicators showed several stages in plant succession: from weeds to stable patches of late successional plant species (fertility islands). Plant species diversity decreased along the transect, except at the fertility islands, where ecological indexes were similar to those ones obtained at the border of the tailings. The plant species inventory revealed that pioneer vegetation is mainly formed by widespread, opportunist and halophyte plant species while in the fertility islands native shrubs and forest plant species were also found.

These results point that the presence of patches of favourable edaphic niches with contrasting soil properties for plant growth in the tailings may have promoted the selective establishment of pioneer vegetation. The distribution of these patches should be considered when phytoremediation techniques such as ploughing or addition of amendments are proposed for revegetation, in order to benefit from favourable niches for plant establishment. The advantages of phytomanagement in comparison with other remediation technologies are discussed.

Funding: Financial support for this research was provided by the Fundacion Séneca de la Comunidad Autónoma de la Región de Murcia (Project 15296/PI/10) and Ministerio de Economía y Competitividad of Spain and FEDER (Project CTM2011-23958). Dr. Héctor M. Conesa thanks the Spanish Ministerio de Economía y Competitividad and UPCT for funding through the “Ramon y Cajal” programme (Ref. RYC-2010-05665).

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last modified 2014-06-19