Summary

The unique co-located long-term ECN measurements of DOC and other solutes in atmospheric deposition, soil water and stream water at Moor House provide an opportunity to quantify DOC gains and losses. These are the key points made in the 2016 special issue paper.
  • An issue of concern for management of the uplands has been the widespread long term increase in the flux of dissolved organic carbon (DOC) in drainage waters, brought to international attention through observations by the UK Upland Waters Monitoring Network and ECN (see for example paper by Sawicka et al.).
  • Rising concentrations of Dissolved Organic Carbon (DOC) in surface waters (see Sawicka et al. 27-31) might be expected to be accompanied by greater losses of carbon from waters to the atmosphere (as CO2 and methane).The flux represents a potentially significant component of the global carbon cycle, but to date, its incorporation within global carbon models, and the understanding of the potential implications for long term increases in DOC export have been hampered by the lack of understanding of the extent to which DOC is processed within drainage waters, or exported directly to the oceans.
  • The unique co-located long-term ECN measurements of DOC and other solutes in atmospheric deposition, soil water and stream water at Moor House provide an opportunity to quantify DOC gains and losses at the site.
  • The authors describe two approaches to estimating these gains and losses within the Trout Beck, a stream draining Moor House. These provided conflicting results whereby the Trout Beck was found to be either gaining or losing organic carbon relative to soil water DOC (the primary DOC source). Despite this ambiguity, however, this novel approach of blending data from co-located soil and surface water time series, showed considerable potential for contributing to our understanding of stream carbon dynamics.

 

Reference: Moody, CS., Worrall, F. and Burt, TP. (2016). Identifying DOC gains and losses during a 20-year record in the Trout Beck catchment, Moor House, UK. Ecological Indicators68, 102-114. DOI: 10.1016/j.ecolind.2015.11.033.