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Biogeochemistry

, Volume 70, Issue 3, pp 357–368 | Cite as

Phosphorus Retention at the Redox Interface of Peatlands Adjacent to Surface Waters in Northeast Germany

  • D. Zak
  • J. Gelbrecht
  • C. E. W. Steinberg
Article

Abstract

It is demanded currently in public discussions to rewet peatlands and re-establish their function as nutrient sinks. But due to high phosphorus (P) concentrations in the pore water of rewetted peatlands (40–420 μM) it is hypothesized that they can act as a surplus P source for adjacent surface waters and consequently support the eutrophication of such waters. Our detailed investigations of processes at the redox interface in four fens with different geochemical character show the dependence of P retention from the chemistry of the pore water. The precipitation of Fe(III) oxyhydroxide led to high retention of phosphorus and other substances such as DOC and sulphate in the eutrophic fens. When molar Fe/P ratios were larger than about 3 the initially high P concentrations in the anaerobic pore water (20–210 μM) decreased to concentrations below 1 μM under aerobic conditions. Thus, after rewetting high pore water concentrations of P do not automatically result in an increased P load to adjacent surface waters compared to pre-rewetting conditions. An enhanced P export to adjacent surface waters from eutrophic fens can be expected when the Fe/P ratio is smaller than 3 in the anaerobic pore water. In our investigations of natural, oligotrophic to mesotrophic fens the precipitation of Fe(III) oxyhydroxide was inhibited by the formation of stable dissolved Fe ∼ humic complexes. P retention in these fens was only related to the DOC concentrations at the redox interface, so that lower DOC concentrations concurred with higher P retention. The P equilibrium concentrations in an aerobic environment can be higher than that of eutrophic fens with Fe/P ratios larger than about 3 in the anaerobic pore water.

Keywords

Fen Humic substances Iron Phosphorus retention Pore water Redox interface 

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References

  1. Buffle J. 1988. Complexation properties of homologous comlexants and choice of measuring methods. In: Complexation Reactions in Aquatic Systems: an Analytical Approach. Ellis Horwood, Chichester, UK, pp. 304–383.Google Scholar
  2. Buffle, J., De Vitre, R.R., Perret, D., Leppard, G.G. 1989Physico-chemical characteristics of a colloidal iron phosphate species formed at the oxic-anoxic interface of a eutrophic lakeGeochim. Cosmochim. Acta53399408CrossRefGoogle Scholar
  3. Dolfing, J., Chardon, W.J., Japenga, J. 1999Association between colloidal iron, aluminium, phosphorus, and humic acidsSoil Science164171179CrossRefGoogle Scholar
  4. Driescher E., Gelbrecht J. 1999. Investigation of springs – a means to estimate the geogenic phosphorus background of surface waters. Berlin, ISSN-Nr. 1432–508X Berichte des IGB, Heft 8, pp. 107–118.Google Scholar
  5. Gelbrecht, J., Koppisch, D. 2001Phosphor-UmsetzungsprozesseSuccow, M.Joosten, H. eds. Landschaftsökologische MoorkundeSchweizerbartStuttgart2426Google Scholar
  6. Gelbrecht J., Lengsfeld H. 1998. Phosphorus in fens adjacent to surface waters. Berlin, ISSN-Nr. 1432-508X Berichte des IGB, Heft 5. pp. 94–100.Google Scholar
  7. Gelbrecht J., Driescher E., Exner H.J., Köhler J., (1999). Input, content and dynamics of phosphorus in the River Schlaube basin (SE Brandenburg). Berlin, ISSN-Nr. 1432-508X Berichte des IGB, Heft 9, pp. 143–170.Google Scholar
  8. Goldberg, S., Sposito, G. 1984A chemical model of phosphate adsorption by soils: I. Reference oxide mineralsSoil Sci. Soc. Am. J.48772778Google Scholar
  9. Huber, S.A., Frimmel, F.H. 1996Size-exclusion-chromatography with organic carbon detection (LCOCD): A fast and a reliable method for characterisation of hydrophilic organic matter in natural watersVom Wasser86277290Google Scholar
  10. Hesslein, R.H. 1976An in situ sampler for close interval porewater studiesLimnol. Oceanogr.21912914Google Scholar
  11. Jensen, H.S., Kristensen, P., Jeppesen, E., Skytthe, A. 1992Iron: phosphorus ratio in surface sediments in shallow lakesHydrobiology235/236731743CrossRefGoogle Scholar
  12. Kawashima, M., Tainaka, Y., Hori, T., Koyama, M., Takamatsu, T. 1986Phosphate adsorption onto hydrous manganese(IV)oxide in the presence of divalent cationsWat. Res.20471475CrossRefGoogle Scholar
  13. Landgraf, L. 1998Landschaftsökologische Untersuchungen an einem wiedervernässten Niedermoor an der Nuthe-Nieplitz-Niederung. Bd. 18Studien und Tagungsberichte des LUA Brandenburg181120Google Scholar
  14. Laxen, D.P.H. 1985Trace metal adsorption/coprecipitation on hydrous ferric oxide under realistic conditions. The role of humic substancesWat. Res.1912291236CrossRefGoogle Scholar
  15. Lijklema, L. 1980Interaction of orthophosphate with iron(III) and aluminium hydroxidesAm. Chem Soc.14537541Google Scholar
  16. Mitsch J.W., Gosselink J.W., 1993. Biogeochemistry of wetlands. In: Wetlands Van Nostrand Reinhold, New York, pp. 114–147.Google Scholar
  17. Peiffer, S., Walton-Day, K., Macalady, D.L. 1999The interaction of natural organic matter with iron in a wetland (Tennessee Park, Colorado) receiving acid mine drainageAquat. Geochem.5207223CrossRefGoogle Scholar
  18. Roden, E.E., Edmonds, J.W. 1997Phosphate mobilization in iron-rich anaerobic sediments: microbial Fe(III)oxide reduction versus iron-sulfide formationArch. Hydrobiol.139347378Google Scholar
  19. Sachse, A., Babenzien, D., Ginzel, G., Gelbrecht, J., Steinberg, C.E.W. 2001Characterization of dissolved organic carbon (DOC) in a dystrophic lake and an adjacent fenBiogeochemistry54279296CrossRefGoogle Scholar
  20. Steinmann, P., Shotyk, W. 1996Sampling anoxic porewaters in peatlands using ’peeper’ for in situ-filtrationFresh. J. Anal. Chem.354709713Google Scholar
  21. Steinmann, P., Shotyk, W. 1997Chemical composition, and redox state of sulfur and iron in complete vertical porewater profiles from two Sphagnum peat bogsGeochim. Cosmochim. Acta6111431163CrossRefGoogle Scholar
  22. Tipping, E. 1980The adsorption of aquatic humic substances by iron oxidesGeochim. Cosmochim. Acta45191199CrossRefGoogle Scholar
  23. Yao, W., Millero, F.J. 1996Adsorption of phosphate on manganese dioxide in seawaterEnviron. Sci. Technol.30536541CrossRefGoogle Scholar
  24. Zeitz J., 1997. Zur Geochemie von Mooren. In: Matschulat, Tobschall and Voigt (eds) Geochemie Springer Verlag, Berlin, pp. 75–94.Google Scholar

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  1. 1.Institute of Freshwater Ecology and Inland Fisheries (IGB)Chemical LaboratoryBerlinGermany

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