4.8 Article

The role of terrestrial productivity and hydrology in regulating aquatic dissolved organic carbon concentrations in boreal catchments

Journal

GLOBAL CHANGE BIOLOGY
Volume 28, Issue 8, Pages 2764-2778

Publisher

WILEY
DOI: 10.1111/gcb.16094

Keywords

boreal catchments; catchment size; discharge; DOC; GPP; landscape; RE; terrestrial productivity

Funding

  1. Kone project-'The role of terrestrial productivity on fluxes of DOC in watersheds (Maaekosysteemien tuottavuuden merkitys liukoisen orgaanisen hiilen virtoihin valuma-alueilla)' [201906598]
  2. Academy of Finland [337549, 326818]
  3. Atmosphere and Climate Competence Center (ACCC) [337550]
  4. Swedish Infrastructure for Ecosystem Science (SITES)
  5. VR extreme event project
  6. Swedish Research Council for Sustainable Development (FORMAS)
  7. SKB
  8. European Union [734317]
  9. European Commission-Horizon 2020 Research and innovation programme under Integrative and Comprehensive Understanding on Polar Environments (ICUPE) [689443]
  10. INAR RI Ecosystems (Academy of Finland) [304460]
  11. Fulbright Finland Foundation
  12. Saastamoinen Foundation Grant in Health and Environmental Sciences
  13. Academy of Finland (AKA) [304460, 326818, 304460, 326818] Funding Source: Academy of Finland (AKA)
  14. Marie Curie Actions (MSCA) [734317] Funding Source: Marie Curie Actions (MSCA)

Ask authors/readers for more resources

This study investigated the impacts of climate change-induced terrestrial productivity increase and hydrology changes on DOC concentrations in boreal catchments. The combined effects of terrestrial productivity and discharge explained 62% of aquatic DOC variations, with different impacts observed in catchments of varying sizes. Increasing RE always made a positive contribution to DOC concentration, highlighting the importance of DOC fluxes in regulating ecosystem C budgets.
The past decades have witnessed an increase in dissolved organic carbon (DOC) concentrations in the catchments of the Northern Hemisphere. Increasing terrestrial productivity and changing hydrology may be reasons for the increases in DOC concentration. The aim of this study is to investigate the impacts of increased terrestrial productivity and changed hydrology following climate change on DOC concentrations. We tested and quantified the effects of gross primary production (GPP), ecosystem respiration (RE) and discharge on DOC concentrations in boreal catchments over 3 years. As catchment characteristics can regulate the extent of rising DOC concentrations caused by the regional or global environmental changes, we selected four catchments with different sizes (small, medium and large) and landscapes (forest, mire and forest-mire mixed). We applied multiple models: Wavelet coherence analysis detected the delay-effects of terrestrial productivity and discharge on aquatic DOC variations of boreal catchments; thereafter, the distributed-lag linear models quantified the contributions of each factor on DOC variations. Our results showed that the combined impacts of terrestrial productivity and discharge explained 62% of aquatic DOC variations on average across all sites, whereas discharge, gross primary production (GPP) and RE accounted for 26%, 22% and 3%, respectively. The impact of GPP and discharge on DOC changes was directly related to catchment size: GPP dominated DOC fluctuations in small catchments (<1 km(2)), whereas discharge controlled DOC variations in big catchments (>1 km(2)). The direction of the relation between GPP and discharge on DOC varied. Increasing RE always made a positive contribution to DOC concentration. This study reveals that climate change-induced terrestrial greening and shifting hydrology change the DOC export from terrestrial to aquatic ecosystems. The work improves our mechanistic understanding of surface water DOC regulation in boreal catchments and confirms the importance of DOC fluxes in regulating ecosystem C budgets.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.8
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available