Patterns in diatom community structure in rivers submitted to heavy metal inputs in different countries and consequences for biomonitoring
Patrones estructurales de las comunidades de diatomeas en ríos sometidos a una contaminación por metales pesados de diferentes países y consecuencias para el biocontrol
Patrons de distribution des diatomées en rivières impactées par des métaux lourds dans différents pays, conséquences pour le biomonitoring
Résumé
A large database of river diatoms (comprising more than 450 taxa) was constituted based on field surveys carried out in different countries (France, Spain, Switzerland, Canada, Vietnam), in rivers exposed to various loads of heavy metals in the water. After taxonomy harmonization, the patterns in diatom community structure were investigated for 163 samples, all collected from hard substrates. The biotypology (i.e. structuration of the diatom dataset) indicates that the species are influenced by the hydroecoregional context as well as metal inputs. The most structuring environmental parameters are investigated, and discriminating analyses are used to determine the relevance of some particular species (e.g. Eolimna minima, Achnanthidium minutissimum) as well as teratological forms for the biomonitoring of heavy metal pollutions.