Biogeochemistry

, Volume 123, Issue 3, pp 363–377

Spatial controls on dissolved organic carbon in upland waters inferred from a simple statistical model

  • Donald T. Monteith
  • Peter A. Henrys
  • Chris D. Evans
  • Iain Malcolm
  • Ewan M. Shilland
  • M. G. Pereira
Article

DOI: 10.1007/s10533-015-0071-x

Cite this article as:
Monteith, D.T., Henrys, P.A., Evans, C.D. et al. Biogeochemistry (2015) 123: 363. doi:10.1007/s10533-015-0071-x

Abstract

Dissolved organic carbon (DOC) concentrations in upland surface waters in many northern hemisphere industrialised regions are at their highest in living memory, provoking debate over their “naturalness”. Because of the implications for drinking water treatment and supply there is increasing interest in the potential for mitigation through local land management, and for forecasting the likely impact of environmental change. However, the dominant controls on DOC production remain unresolved, hindering the establishment of appropriate reference levels for specific locations. Here we demonstrate that spatial variation in long-term average DOC levels draining upland UK catchments is highly predictable using a simple multiple logistic regression model comprising variables representing wetland soil cover, rainfall, altitude, catchment sensitivity to acidification and current acid deposition. A negative relationship was observed between DOC concentration and altitude that, for catchments dominated by organo-mineral soils, is plausibly explained by the combined effects of changing net primary production and temperature-dependent decomposition. However, the magnitude of the altitude effect was considerably greater for catchments with a high proportion of wetland cover, suggesting that additional controls influence these sites such as impeded respiratory loss of carbon in wet soils and/or an increased susceptibility to water level drawdown at lower altitudes. The model suggests (1) that continuing reductions in sulphur deposition on acid sensitive organo-mineral soils, will drive further significant increases in DOC and, (2) given the differences in the magnitude of the observed altitude-DOC relationships, that DOC production from catchments with peat-dominated soils may be more sensitive to climate change than those dominated by mineral soils. However, given that mechanisms remain unclear, the latter warrants further investigation.

Keywords

Dissolved organic carbonDissolved organic matterUpland watersAcidificationRecoveryClimate changeLand use

Supplementary material

10533_2015_71_MOESM1_ESM.doc (270 kb)
Supplementary material 1 (DOC 270 kb)
10533_2015_71_MOESM2_ESM.doc (95 kb)
Supplementary material 2 (DOC 95 kb)

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Donald T. Monteith
    • 1
  • Peter A. Henrys
    • 1
  • Chris D. Evans
    • 2
  • Iain Malcolm
    • 3
  • Ewan M. Shilland
    • 4
  • M. G. Pereira
    • 1
  1. 1.NERC Centre for Ecology & Hydrology, Lancaster Environment CentreLancasterUK
  2. 2.NERC Centre for Ecology & Hydrology, Environment Centre WalesBangorUK
  3. 3.Marine Scotland Freshwater LaboratoryPitlochryScotland, UK
  4. 4.Environmental Change Research CentreUniversity College LondonLondonUK