Links between pseudometallophytes and rhizosphere microbial communities in a metalliferous soil

Short-term improvements in soil health derived from pseudometallophytes growth and metal phytoremediation were quantified based upon specific microbial properties of potential value as bioindicators of soil functioning. To this aim, plant consortia, consisting of 1-3 pseudometallophytes with different metal-tolerance strategies (hyperaccumulator: Noccaea caerulescens; accumulator: Rumex acetosa; excluder: Festuca rubra), were grown in a mine soil. At the end of the experiment, soil microbial biomass, activity, structural and functional community profiling, and stability were determined. Growing together with N. caerulescens stimulated the growth of the other two pseudometallophytes. The combination of R. acetosa and N. caerulescens extracted the highest amounts of Zn. Except for beta-glucosidase, a negative correlation was found between enzyme activities and number of pseudometallophytes present in the study pots. Microbial biomass C was highest in the presence of all three pseudometallophytes. The combination of different pseudometallophyte species, which may allow for a greater exploitation of potential niche space, appears promising for phytoremediation. When quantifying soil health, the importance of measuring various types of soil microbial properties has been highlighted, as the response observed was different in each of them. (C) 2012 Elsevier GmbH. All rights reserved.