Abstract

We investigated the effects of ditch blocking on fluvial carbon concentrations and fluxes at a 5-year, replicated, control-intervention field experiment on a blanket peatland in North Wales, UK. The site was hydrologically instrumented, and run-off via open and blocked ditches was analysed for dissolved organic carbon (DOC), particulate organic carbon, dissolved carbon dioxide, and dissolved methane. DOC was also analysed in peat porewater and overland flow. The hillslope experiment was embedded within a paired control-intervention catchment study, with 3years of preblocking and 6years of postblocking data. Results from the hillslope showed large reductions in discharge via blocked ditches, with water partly redirected into hillslope surface and subsurface flows, and partly into remaining open ditches. We observed no impacts of ditch blocking on DOC, particulate organic carbon, dissolved carbon dioxide or methane in ditch waters, DOC in porewaters or overland flow, or stream water DOC at the paired catchment scale. Similar DOC concentrations in ditch water, overland flow, and porewater suggest that diverting flow from the ditch network to surface or subsurface flow had a limited impact on concentrations or fluxes of DOC entering the stream network. The subdued response of fluvial carbon to ditch blocking in our study may be attributable to the relatively low susceptibility of blanket peatlands to drainage, or to physical alterations of the peat since drainage. We conclude that ditch blocking cannot be always be expected to deliver reductions in fluvial carbon loss, or improvements in the quality of drinking water supplies.

Keywords

blanket bog; dissolved orgainc carbon; fluvial carbon; Peatland; re-wetting

Published in

Hydrological Processes
2018, Volume: 32, number: 13, pages: 2141-2154
Publisher: WILEY

SLU Authors

• Peacock, Michael

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    
  • Bangor University

Sustainable Development Goals

Ensure availability and sustainable management of water and sanitation for all


UKÄ Subject classification

Oceanography, Hydrology, Water Resources


Publication identifier

DOI: https://doi.org/10.1002/hyp.13158

Permanent link to this page (URI)

https://res.slu.se/id/publ/95984