RT Journal Article
SR Electronic
T1 Riparian vegetation limits oxidation of thermodynamically unfavorable bound-carbon stocks along an aquatic interface
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 105486
DO 10.1101/105486
A1 Emily B. Graham
A1 Malak Tfaily
A1 Alex R. Crump
A1 Amy E. Goldman
A1 Evan Arntzen
A1 Elvira Romero
A1 C. Tom Resch
A1 David W. Kennedy
A1 James C. Stegen
YR 2017
UL http://biorxiv.org/content/early/2017/02/03/105486.abstract
AB In light of increasing terrestrial carbon (C) transport across aquatic boundaries, the mechanisms governing organic carbon (OC) oxidation along terrestrial-aquatic interfaces are crucial to future climate predictions. Here, we investigate biochemistry, metabolic pathways, and thermodynamics corresponding to OC oxidation in the Columbia River corridor. We leverage natural vegetative differences to encompass variation in terrestrial C inputs. Our results suggest that decreases in terrestrial C deposition associated with diminished riparian vegetation induce oxidation of physically-bound (i.e., mineral and microbial) OC at terrestrial-aquatic interfaces. We also find that contrasting metabolic pathways oxidize OC in the presence and absence of vegetation and—in direct conflict with the concept of ‘priming’—that inputs of water-soluble and thermodynamically-favorable terrestrial OC protects bound-OC from oxidation. Based on our results, we propose a mechanistic conceptualization of OC oxidation along terrestrial-aquatic interfaces that can be used to model heterogeneous patterns of OC loss under changing land cover distributions.