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Temperature and precipitation drive temporal variability in aquatic carbon and GHG concentrations and fluxes in a peatland catchment
Author(s) -
Dinsmore K. J.,
Billett M. F.,
Dyson K. E.
Publication year - 2013
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.12209
Subject(s) - dissolved organic carbon , environmental science , peat , carbon cycle , greenhouse gas , aquatic ecosystem , environmental chemistry , carbon fibers , hydrology (agriculture) , ombrotrophic , total organic carbon , ecology , atmospheric sciences , ecosystem , chemistry , bog , biology , geology , materials science , geotechnical engineering , composite number , composite material
The aquatic pathway is increasingly being recognized 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 data set of all aquatic carbon and GHG species from an ombrotrophic Scottish peatland. Measured species include particulate and dissolved forms of organic carbon (POC, DOC), dissolved inorganic carbon (DIC), CO 2 , CH 4 and N 2 O. 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 . Although 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 gross primary productivity ( 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 and 48%, evasion estimates had 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.