Trace element transfer from soil to leaves of macrophytes along the Jalle d’Eysines River, France and their potential use as contamination biomonitors
Résumé
Biomonitoring complements the physico-chemical analysis of environmental matrices, accounting for the subtle biological changes in organisms affected by exogenous chemicals. Here, the relationships between the concentrations of trace elements (TE) in the soil, soil-pore water and leaves of seven rooted macrophytes (Ranunculus acris L., Phragmites australis (Cav.) Trin. Ex Steud., Carex riparia Ehrh., Lythrum salicaria L., Iris pseudacorus L., Juncus effusus L., and Phalaris arundinacea L.) were investigated along an urban river – the Jalle d’Eysines River, France – with increasing TE contamination in riverbank soils, from its source to its confluence with the Garonne River. Copper, Zn, Cd, Cr, Pb, Ni, Mo and As were considered. Macrophytes were sampled in June 2011, at the peak of the growing season. For five species, a canonical correspondence analysis (CCA) was used to assess correlations between foliar TE concentrations and total TE concentrations in the soil. Along the Jalle d’Eysines River, P. australis and P. arundinacea are relevant biomonitors for soil Mo contamination. P. australis and C. riparia biomonitor soil Cd contamination, while R. acris is a relevant biomonitor of soil Ni contamination. Copper and Mo concentrations in the soil-pore water are monitored by, respectively P. arundinacea and P. australis.