18 Jul Comunicación oral en ICOBTE 2017
Título: “Effects of the long-term phytomanagement of Cu mine-soils on microbial diversity and soil quality.”
Socios implicados: IIAG-CSIC, USC, NEIKER, INRA
Datos publicación: The International Conference on the Biogeochemistry of Trace Elements (ICOBTE) 2017, ETH Zurich, Switzerland, July 16-20
Resumen (en inglés): (Aided) phytostabilisation has been proposed as a sustainable technique for decreasing the environmental risks associated with metal(loid)-enriched mine tailings.
Phytomanaging polluted soils can gradually result in an increase in microbial diversity, carbon sequestration, and soil quality and functionality. However, there is a lack of field evidence demonstrating the provision of such vital ecosystem services. Here, the medium- to long-term effects of aided phytostabilisation on soil physicochemical properties, metal availability and fertility, as well as microbial activity and diversity, were evaluated in Cu mine tailings amended with three organic waste-based amendments and planted with Populus nigra, Salix viminalis or Agrostis capillaris cv. Highland. The field trials were established in spring 2011 and form part of the PhytoSUDOE network of phytomanaged trace element-contaminated field sites (PhytoSUDOE Project (SOE1/P5/E0189)). Three soil amendments were added at an addition rate of 250 kg Mg-1 dry tailings, and based on different combinations of municipal solid wastes, bark chippings, fly ash from wood bark combustion, foundry sand, aluminium oxides or ferrihydrite-type iron oxides. Tree species were planted following a short rotation coppicing system (10,000 trees ha-1) and grass seeded at a rate equivalent to 250 kg ha-1. The first coppicing was carried out after 4 years, with a biomass productivity of 4-10 t ha-1. Baseline trace metal content and general physico- and bio-chemical properties were determined before amendment addition/planting. Soil general properties (improvements in pH, nutrient availability, and reductions in Cu bioavailability) were monitored after 1, 2, 3 and 6 years after planting. Soil enzyme activities (urease, phosphatase, arylsulfatase, ß-glucosidase, etc.), respiration, potentially mineralisable nitrogen and nitrification rate, and community-level physiological profiling (BIOLOG ECOPlates™), and taxonomic diversity of soil microorganisms (bacteria, archaea, fungi) are being assessed after 6 years using next generation sequencing.Improvements in pH, cation exchange capacity (base saturation) and fertility, and significant reductions in soil Cu availability, have been observed over time. Here we will compare soil microbial activity and diversity between phytomanaged contaminated soils and non-phytomanaged contaminated soils. Future research will be aimed at identifying interactions between belowground structural and functional soil biodiversity with aboveground plant diversity, as well as links between soil biodiversity and ecosystem functions.