Jeffrey P. Chanton

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Temporal variability in the 13C of foliage (δ13CF), soil (δ13CS) and ecosystem (δ13CR) respired CO2 was contrasted between a 17.2-m tall evenly aged loblolly pine forest and a 35-m tall unevenly aged mature second growth mixed broadleaf deciduous forest in North Carolina, USA, over a 2-year period. The two forests are located at the Duke Forest within a(More)
Antarctic permafrost soils have not received as much geocryological and biological study as has been devoted to the ice sheet, though the permafrost is more stable and older and inhabited by more microbes. This makes these soils potentially more informative and a more significant microbial repository than ice sheets. Due to the stability of the subsurface(More)
Although northern peatlands contribute significantly to natural methane emissions, recent studies of the importance and type of methanogenesis in these systems have provided conflicting results. Mechanisms controlling methanogenesis in northern peatlands remain poorly understood, despite the importance of methane as a greenhouse gas. We used 16S rRNA gene(More)
Landfills are the third largest source of anthropogenic CH4 in the United States, and there is potential for reduction in this source of greenhouse gases and other contaminants. The objective of this work was to contrast emissions of CH4 and non-methane organic compounds (NMOCs) from landfill cells covered with soil or a biologically active cover consisting(More)
Many developed countries have targeted landfill methane recovery among greenhouse gas mitigation strategies, since methane is the second most important greenhouse gas after carbon dioxide. Major questions remain with respect to actual methane production rates in field settings and the relative mass of methane that is recovered, emitted, oxidized by(More)
Our objective was to evaluate the hypothesis that measurements of caffeine, nutrients, and indicator bacteria can distinguish human versus non-human sources of surface water contamination in contrasting environments. A second objective was to determine if natural sources of caffeine were significant in unpopulated areas. Caffeine was measured in an isolated(More)
The delta 13C of pine needle CO2 evolved in darkness (delta 13Cr) for slash pine trees (Pinus elliottii) was determined by placing recently collected pine needles in darkness and collecting respired CO2 over a short time period (<15 min). Delta 13Cr measurements were made over several 24 h periods to test the hypothesis that significant variation in delta(More)
BACKGROUND Subsurface fluids from deep-sea hydrocarbon seeps undergo methane- and sulfur-cycling microbial transformations near the sediment surface. Hydrocarbon seep habitats are naturally patchy, with a mosaic of active seep sediments and non-seep sediments. Microbial community shifts and changing activity patterns on small spatial scales from seep to(More)
Field investigations of lateral gas transport and subsequent emissions in soil adjacent to an old landfill in Denmark were conducted during a 1-year period. A significant seasonal variation in the emissions with high carbon dioxide and low methane fluxes in the summer (May to October) was observed. This was attributed to methane oxidation. Diurnal(More)
Natural chemical tracers of groundwater discharge (222Rn and CH4) were surveyed to evaluate possible patterns of groundwater interactions with surface water in Florida Bay. Radon and methane concentrations in water samples collected from wells, solution holes, canals, and Florida Bay showed a significant correlation, despite the fact that these two trace(More)