Publikationen

Sphagnum-dominated bog systems are highly effective yet variable sources of bio-available iron to marine waters

Autor(en)
Regina Krachler, Rudolf Krachler, Gabriele Wallner, Peter Steier, Yasin El Abiead, Hubert Wiesinger, Franz Jirsa, Bernhard Keppler
Abstrakt

Iron is a micronutrient of particular interest as low levels of iron limit primary production of phytoplankton and carbon fluxes in extended regions of the world's oceans. Sphagnum-peatland runoff is extraordinarily rich in dissolved humic-bound iron. Given that several of the world's largest wetlands are Sphagnum-dominated peatlands, this ecosystem type may serve as one of the major sources of iron to the ocean. Here, we studied five near-coastal creeks in North Scotland using freshwater/seawater mixing experiments of natural creek water and synthetic seawater based on a Fe-59 radiotracer technique combined with isotopic characterization of dissolved organic carbon by Accelerator Mass Spectrometry. Three of the creeks meander through healthy Sphagnum-dominated peat bogs and the two others through modified peatlands which have been subject to artificial drainage for centuries. The results revealed that, at the time of sampling (August 16-24, 2014), the creeks that run through modified peatlands delivered 11-15 mu g iron per liter creek water to seawater, whereas the creeks that run through intact peatlands delivered 350-470 mu g iron per liter creek water to seawater. To find out whether this humic-bound iron is bio-available to marine algae, we performed algal growth tests using the unicellular flagellated marine prymnesiophyte Diacronema lutheri and the unicellular marine green alga Chlorella salina, respectively. In both cases, the riverine humic material provided a highly bio-available source of iron to the marine algae. These results add a new item to the list of ecosystem services of Sphagnum-peatlands. (C) 2016 The Authors. Published by Elsevier B.V.

Organisation(en)
Institut für Anorganische Chemie, Isotopenphysik, Department für Funktionelle und Evolutionäre Ökologie, Institut für Analytische Chemie
Externe Organisation(en)
University of Johannesburg (UJ)
Journal
Science of the Total Environment
Band
556
Seiten
53-62
Anzahl der Seiten
10
ISSN
0048-9697
DOI
https://doi.org/10.1016/j.scitotenv.2016.03.012
Publikationsdatum
06-2016
Peer-reviewed
Ja
ÖFOS 2012
104003 Anorganische Chemie, 104023 Umweltchemie, 105306 Ozeanographie
Schlagwörter
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/sphagnumdominated-bog-systems-are-highly-effective-yet-variable-sources-of-bioavailable-iron-to-marine-waters(06284b4e-d54d-4c67-b05d-93803e2ee029).html