Impacts of rewetting on peat, hydrology and water chemical composition over 15 years in two finished peat extraction areas in Sweden

Abstract

Restoration of wetlands is a high priority world-wide. Peat extraction areas can be restored by rewetting, however affecting the environment. It could be expected to turn the drained peat-cutover area from a source to a sink of most elements. This study examined effects of such rewetting on peat, hydrology and water chemistry over 15 years at two sites in Sweden; the nutrient-poor Porla peatland and the nutrient-rich Vastkarr peatland. Rewetting caused minor changes to peat chemistry, but at the Vastkarr site ammonium concentrations increased in superficial peat layers while nitrate decreased. In terms of hydrology, rewetting of the Porla site decreased annual runoff and both high and low discharges. Water pH at the Porla site stayed fairly stable, but at the Vastkarr site pH, after an initial 4 years dip, gradually increased to higher values than before rewetting. Water colour and organic matter content were fairly stable, but slightly lower values were found after 15 years than in initial 4-5 years. The concentrations of base cations and of inorganic N were lower after rewetting, while total P was higher. However, these impacts could change from an initial phase as the wetlands in the long-term perspective develop into mires.

Keywords

After-use; Hydrochemistry; Peatland; Restoration; Wetland

Published in

Wetlands Ecology and Management
2017, volume: 24, number: 4, pages: 405-419

SLU Authors

• Lundin, Lars

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Nilsson, Torbjörn

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Jordan, Sabine

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Lode, Elve

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Strömgren, Monika

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

Global goals (SDG)

SDG6 Clean water and sanitation
SDG15 Life on land

UKÄ Subject classification

Environmental Sciences
Oceanography, Hydrology, Water Resources

Publication identifier

• DOI: https://doi.org/10.1007/s11273-016-9524-9

Permanent link to this page (URI)

https://res.slu.se/id/publ/78408