Differential responses of the freshwater wetland species Juncus effusus L. and Caltha palustris L. to iron supply in sulfidic environments.
Sulfur pollution can lead to serious problems in freshwater wetlands, including phosphorus eutrophication and sulfide toxicity. We tested the effects of anaerobic iron-rich groundwater discharge in fens, simulated by iron injection, on two characteristic species (Juncus effusus and Caltha palustris) in a sulfidic environment. Biomass production of C. palustris roots showed an optimum response to the combined addition of iron and sulfide, with highest values at intermediate concentrations of both substances. Iron deficiency apparently occurred at low iron concentrations, while at high iron concentrations, growth was decreased. For J. effusus, in contrast, no toxic effects were found of both iron and sulfide. This could be explained by larger radial oxygen loss (ROL) of J. effusus and could not be explained by differences in phosphorous concentrations. The results of our experiments confirm that iron-rich groundwater discharge has the potential to affect vegetation composition through toxicity modification in sulfidic environments.
Van der Welle
Marlies E W
ME
Department of Aquatic Ecology and Environmental Biology, Radboud University Nijmegen, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands. m.vanderwelle@science.ru.nl
Niggebrugge
Karla
K
Lamers
Leon P M
LP
Roelofs
Jan G M
JG
D018533:Biomass; D004463:Ecology / Q000379:methods; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D005618:Fresh Water; D007501:Iron / Q000633:toxicity*; D029594:Onagraceae / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development; D018520:Plant Shoots / Q000254:growth & development / Q000378:metabolism; D029626:Ranunculaceae / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D013440:Sulfides / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D053833:Wetlands
D013440:Sulfides; D014874:Water Pollutants, Chemical; D007501:Iron; D010100:Oxygen