"What we report was completely unexpected," said oceanographer and biogeochemist Samantha Joye. "This temperature-driven decoupling short-circuits organic matter recycling and will be of interest to a broad spectrum of biologists, geochemists and environmental scientists."
The research will be published the week of Nov.14 in the Proceedings of the National Academy of Sciences. Co-author of the study is Nathaniel B. Weston, who worked with Joye as a doctoral student at UGA. He is now at the Patrick Center for Environmental Research at the Academy of Natural Sciences in Philadelphia.
"These surprising results show that temperature dependence strongly affects the efficiency of organic matter breakdown and need to be taken into account in models of the role of sediments in the global carbon cycle," said Paul Kemp, program director in the National Science Foundation's biological oceanography program, which supported the research.
Scientists have long known that buried organic carbon in marine sediments plays a crucial role in many terrestrial and atmospheric processes. The number of anaerobic microorganisms that chew away at this carbon is vast, and they can hydrolyze, ferment or terminally oxidize organic compounds.
"The microbes responsible for all but the final step of organic matter degradation in sediments are often ignored, and we were interested in opening the microbial 'black box' in sediments and clarifying the temperature controls on different micro
Contact: Kim Carlyle
University of Georgia