Journal
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
Volume 122, Issue 1, Pages 131-144Publisher
AMER GEOPHYSICAL UNION
DOI: 10.1002/2016JG003512
Keywords
biodegradation; dissolved organic carbon; dynamics; LC-OCD; reactivity continuum; inttermitent rivers
Funding
- Spanish Ministry of Economy and Competitiveness [CGL2014-57215-C4-2-R]
- COST (European Cooperation in Science and Technology)
- Wenner-Gren Foundation (Sweden)
- Juan de la Cierva postdoctoral grant (Spain) [FJCI-2014-23064]
- FPI predoctoral grant from the Spanish Ministry of Economy and Competitiveness [BES-2012-059655]
Ask authors/readers for more resources
Controls on the degradation of dissolved organic matter (DOM) are complex but key to understand the role of freshwaters in the carbon cycle. Both the origin and previous degradation history have been suggested to determine DOM reactivity, but it is still a major challenge to understand the links between DOM composition and biodegradation kinetics. An appropriate context to study these links are intermittent rivers, as summer drought naturally diversifies DOM sources and sinks. Here we investigated the biodegradation kinetics of DOM in the main aquatic environments present in a temporary river. During dark incubations we traced the dynamics of bulk DOM and its main chromatographic fractions defined using LC-OCD: high molecular weight substances (HMWS), low molecular weight substances (LMWS), and humic substances and building blocks. Bulk DOM decay patterns were successfully fitted to the reactivity continuum (RC) biodegradation model. The RC parameters depicted running waters as the sites presenting a more reactive DOM, and temporary pools, enriched in leaf litter, as the ones with slowest DOM decay. The decay patterns of each DOM fraction were consistent throughout sites. LMWS and HMWS decayed in all cases and could be modeled using the RC model. Notably, the dynamics of LMWS controlled the bulk DOM kinetics. We discuss the mechanistic basis for the chromatographic fractions' kinetics during biodegradation and the implications that preconditioning and summer drought can have for DOM biodegradation in intermittent rivers.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available