Plant and Soil

, Volume 269, Issue 1, pp 109–115

Water table fluctuations and groundwater supply are important in preventing phosphate-eutrophication in sulphate-rich fens: Consequences for wetland restoration

  • Esther C. H. E. T. Lucassen
  • Alfons J. P. Smolders
  • Leon P. M. Lamers
  • Jan G. M. Roelofs
Article

DOI: 10.1007/s11104-004-0554-3

Cite this article as:
Lucassen, E.C.H.E.T., Smolders, A.J.P., Lamers, L.P.M. et al. Plant Soil (2005) 269: 109. doi:10.1007/s11104-004-0554-3

Abstract

Nitrate leaching from agricultural land leads to oxidiation of FeSx in FeSx-containing subsoils resulting in SO42− mobilisation. Pollution of the groundwater with SO42− causes a higher availability of o-PO43−, eutrophication and loss in biodiversity in groundwater fed fens with stagnating surface water. Under natural conditions, fens along the river Meuse are continuously fed by groundwater that besides SO42− mostly also contains high concentrations of NO3 and bivalent cations (Ca2+ and mg2+). During summer groundwater input is restricted resulting in periodic drought. Under these conditions no SO42− induced o-PO43− eutrophication occurs. Periodic drought and a high discharge of NO3, have a strong effect on S and P biogeochemistry in sulphate-rich fens. NO3 inhibits SO42− reduction and concomitant o-PO43− mobilisation in fen sediments by being an energetically more favourable electron acceptor. In addition, NO3 is capable of oxidising reduced Fe compounds, including FeSx, increasing the amount of oxidised Fe in the sediment capable of binding o-PO43−. Periodic drought is important in reincreasing the concentration of oxidised Fe in the top layer of S-rich sediments preventing o-PO43− mobilisation and an undesirable vegetation development. Damming of surface water, in order te restore desiccated sulphate-rich fens, prevents periodic drought and decreases groundwater input. This leads to NO3 depletion, stimulation of SO42− reduction, Fe depletion, o-PO43− mobilisation and, in contrast to what was hoped for, in massive growth of algae, lemnids and fast growing wetland grasses. Therefore discharge of NO3– rich groundwater and the fluctuation of the water table are vital for succesful restoration of desiccated sulphate-rich fens. Successful rewetting of these type of fens, without causing stagnation of surface water and without preventing periodic drought, can be achieved by raising the water table to levels below the potential groundwater table using a controllable dam.

Keywords

agricultural pollutionnitratesediment desiccationvegetationwater dynamics

Copyright information

© Springer 2005

Authors and Affiliations

  • Esther C. H. E. T. Lucassen
    • 1
  • Alfons J. P. Smolders
    • 1
  • Leon P. M. Lamers
    • 1
  • Jan G. M. Roelofs
    • 1
  1. 1.Environmental Biology, Department of EcologyRadboud University NijmegenED Nijmegenthe Netherlands