Temperature and precipitation drive temporal variability in aquatic carbon and GHG concentrations and fluxes in a peatland catchment

Abstract

Biology, 19 (7). 2133-2148. 10.1111/gcb.12209 Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. Accepted ArticleThis article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Accepted ArticleThis article is protected by copyright. All rights reserved.Corresponding Author: Kerry J Dinsmore, 0131 445 8583 kjdi@ceh.ac.uk AbstractThe aquatic pathway is increasingly being recognised as an important component of catchment carbon and greenhouse gas (GHG) budgets, particularly in peatland systems due to their large carbon store and strong hydrological connectivity. In this study we present a complete 5-year dataset of all aquatic carbon and GHG species (POC, DOC, DIC, CO 2 , CH 4 , N 2 O) from an ombrotrophic Scottish peatland. We show that short term variability in concentrations exists across all species and this is strongly linked to discharge. Seasonal cyclicity was only evident in DOC, CO 2 and CH 4 concentration; however temperature correlated with monthly means in all species except DIC. Whilst the temperature correlation with monthly DOC and POC concentrations appeared to be related to biological productivity in the terrestrial system, we suggest the temperature correlation with CO 2 and CH 4 was primarily due to in-stream temperature-dependent solubility. Interannual variability in total aquatic carbon concentration was strongly correlated with catchment GPP indicating a strong potential terrestrial aquatic linkage. DOC represented the largest aquatic carbon flux term (19.3 ± 4.59 g C m -2 yr -1 ), followed by CO 2 evasion (10.0 g C m -2 yr -1 ). Despite an estimated contribution to the total aquatic carbon flux of between 8 -48%, evasion estimates have the greatest uncertainty. Interannual variability in total aquatic carbon export was low in comparison with variability in terrestrial biosphere-atmosphere exchange, and could be explained primarily by temperature and precipitation. Our results therefore suggest that climatic change is likely to have a significant impact on annual carbon losses through the aquatic pathway, and as such aquatic exports are fundamental to the understanding of whole catchment responses to climate change.

Climatic patterns modulate ecosystem and soil respiration responses to fertilization in an alpine meadow on the Tibetan Plateau, China

“…Therefore, rainfall events strongly affect the phenology and growth of alpine plants and CO 2 effluxes. Our results agreed with those of Vargas et al (2012) and Dinsmore et al (2013); i.e., changes in the amount and frequency of rainfall are biophysical drivers that regulate the strength and timing of soil CO 2 efflux. Thus, the accurate quantification of terrestrial C sinks must consider interannual variations in temperature and precipitation.…”

Carbon dioxide transport across the hillslope–riparian–stream continuum in a boreal headwater catchment

“…The net ecosystem carbon balance (NECB) of individual northern latitude catchments has shown them to be net sinks for carbon (Dinsmore et al, , 2013bKoehler et al, 2011;Nilsson et al, 2008;Olefeldt et al, 2012;Roulet et al, 2007). In boreal forest catchments, carbon export via the aquatic pathway (consisting of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), particulate organic carbon (POC) plus dissolved and gaseous CO 2 and CH 4 ) accounted for 4-28 % of carbon uptake via net ecosystem exchange (NEE), representing an im-…”

Biogeochemical contrast between different latitudes and the effect of human activity on spatio-temporal carbon cycle change in Asian river systems

“…In boreal region, the model result showed that about half of annual carbon export occurred in the spring snowmelt period , and this implies the close relation to biological productivity in the soil-plant system, as suggested by Dinsmore et al (2013). The simulated results of discharge underestimated the previous data, whereas the simulated horizontal carbon transports generally overestimated the previous materials.…”