Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane

The second edition of The Biomarker Guide is a fully updated and expanded version of this essential reference. Now in two volumes, it provides a comprehensive account of the role that biomarker technology plays both in petroleum exploration and in understanding Earth history and processes. Biomarkers and Isotopes in the Environment and Human History details the origins of biomarkers and introduces basic chemical principles relevant to their study. It discusses analytical techniques, and applications of biomarkers to environmental and archaeological problems. The Biomarker Guide is an invaluable resource for geologists, petroleum geochemists, biogeochemists, environmental scientists and archaeologists.

The Biomarker Guide

Contributors. Abbreviations. Introduction. 1. Stable isotope chemistry and measurement: a primer. Elizabeth W. Sulzman. Introduction. What isotopes are, what makes them distinct. Properties of ecologically useful stable isotopes. Technological advances and current trends in the ecological use of isotopes. Acknowledgments. References. 2. Sources of variation in the stable isotopic composition of plants. John D. Marshall, J. Renee Brooks, and Kate Lajtha. Introduction. Carbon isotopes. Nitrogen isotopes. Hydrogen and oxygen isotopes. Conclusions. References. 3. Natural 15N- and 13C-abundance as indicators of forest nitrogen status and soil carbon dynamics. Charles T. Garten, Jr, Paul J. Hanson, Donald E. Todd, Jr, Bonnie B. Lau, and Deanne J. Brice. Introduction. Significance of 15N-abundance to soil carbon sequestration. Vertical changes in soil 13C-abundance and soil carbon dynamics. Conclusions. Acknowledgments. References. 4. Soil nitrogen isotope composition. R. Dave Evans. Introduction. Sources of variation in soil 15N. Patterns of soil nitrogen isotope composition. Conclusions. References. 5. Isotopic study of the biology of modern and fossil vertebrates. Paul L. Koch. Introduction. Vertebrate tissues in the fossil record. Controls on the isotopic composition of vertebrate tissues. Preservation of biogenic isotope compositions by vertebrate fossils. Paleobiological applications. Conclusions. A post-script on workshops and literature resources. References. 6. Isotopic tracking of migrant wildlife. Keith A. Hobson. Introduction. Basic principles. Marine systems. Terrestrial systems (excluding deuterium). Using deuterium patterns in precipitation. Conclusions. References. 7. Natural abundance of 15N in marine planktonic ecosystems. Joseph P. Montoya. Introduction. Background. Isotopic variation in marine nitrogen. Source delineation and isotope budgets. Animal fractionation and food web processes. Isotopic transients in marine systems. Compound-specific nitrogen isotope analyses. Conclusions. Acknowledgment. References. 8. Stable isotope studies in marine chemoautotrophically based ecosystems: An update. Cindy Lee Van Dover. Introduction. Isotopic tracing of carbon at methane seeps. Whale falls. Hydrothermal vents. Conclusions. References. 9. Stable isotope ratios as tracers in marine food webs: An update. Robert H. Michener and Les Kaufman. Introduction. Methods of assessing food webs. Phytoplankton and particulate organic carbon. Phytoplankton and particulate organic nitrogen. Marine food webs. Stable isotopes in marine conservation biology. Conclusions. Acknowledgments. References. 10. Stable isotope tracing of temporal and spatial variability in organic matter sources to freshwater ecosystems. Jacques C. Finlay and Carol Kendall. Introduction. Overview of river food webs and stable isotope approaches. Stable isotope ratios of organic matter sources in stream ecosystems. C, N, and S isotopic variability and its applications in river ecology. Conclusions. Acknowledgments. References. 11. Stable isotope tracers in watershed hydrology. Kevin J. McGuire and Jeff McDonnell. Introduction. Basic concepts in watershed hydrology. Why are stable isotopes needed?. General concepts in isotope hydrology. Applications of isotope hydrology in watershed and ecosystem studies. Conclusions. Acknowledgments. References. 12. Tracing anthropogenic inputs of nitrogen to ecosystems. Carol Kendall, Emily M. Elliott, and Scott D. Wankel. Introduction. Isotopic compositions of major N sources to ecosystems. Processes affecting the isotopic composition of DIN. Separating mixing of sources from the effects of cycling. Applications to different environmental settings. What sources of agricultural and urban sources of nitrate can be distinguished using isotopes?. Other tools for tracing anthropogenic contaminants. Conclusions. References. 13. Modeling the dynamics of stable-isotope ratios for ecosystem biogeochemistry. William S. Currie. Introduction. Designing consistent model-data linkages and comparisons. Principles and techniques of stable isotope modeling. Conclusions. Acknowledgments. References. 14. Compound-specific stable isotope analysis in ecology and paleoecology. Richard P. Evershed, Ian D. Bull, Lorna T. Corr, Zoe M. Crossman, Bart E. van Dongen, Claire Evans, Susan Jim, Hazel Mottram, Anna J. Mukherjee, and Richard D. Pancost. Introduction. Why use compound-specific stable isotopes?. Analytical considerations in compound-specific stable isotope analysis. Applications of compound-specific stable isotope approaches in ecology and paleoecology. Conclusions. References. Index

Stable isotopes in ecology and environmental science

Methane is the most abundant organic chemical in Earth's atmosphere, and its concentration is increasing with time, as a variety of independent measurements have shown. Photochemical reactions oxidize methane in the atmosphere; through these reactions, methane exerts strong influence over the chemistry of the troposphere and the stratosphere and many species including ozone, hydroxyl radicals, and carbon monoxide. Also, through its infrared absorption spectrum, methane is an important greenhouse gas in the climate system. We describe and enumerate key roles and reactions. Then we focus on two kinds of methane production: microbial and thermogenic. Microbial methanogenesis is described, and key organisms and substrates are identified along with their properties and habitats. Microbial methane oxidation limits the release of methane from certain methanogenic areas. Both aerobic and anaerobic oxidation are described here along with methods to measure rates of methane production and oxidation experimentally. Indicators of the origin of methane, including C and H isotopes, are reviewed. We identify and evaluate several constraints on the budget of atmospheric methane, its sources, sinks and residence time. From these constraints and other data on sources and sinks we construct a list of sources and sinks, identities, and sizes. The quasi-steady state (defined in the text) annual source (or sink) totals about 310(±60) × 1012 mol (500(±95) × 1012 g), but there are many remaining uncertainties in source and sink sizes and several types of data that could lead to stronger constraints and revised estimates in the future. It is particularly difficult to identify enough sources of radiocarbon-free methane.

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Biogeochemical aspects of atmospheric methane

Methane is the most abundant hydrocarbon in the atmosphere, and it is an important greenhouse gas, which has so far contributed an estimated 20% of postindustrial global warming. A great deal of biogeochemical research has focused on the causes and effects of the variation in global fluxes of methane throughout earth's history, but the underlying microbial processes and their key agents remain poorly understood. This is a disturbing knowledge gap because 85% of the annual global methane production and about 60% of its consumption are based on microbial processes. Only three key functional groups of microorganisms of limited diversity regulate the fluxes of methane on earth, namely the aerobic methanotrophic bacteria, the methanogenic archaea, and their close relatives, the anaerobic methanotrophic archaea (ANME). The ANME represent special lines of descent within the Euryarchaeota and appear to gain energy exclusively from the anaerobic oxidation of methane (AOM), with sulfate as the final electron accept...

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Eckhard Faber

Papers

Biogenic methane formation in marine and freshwater environments: CO2 reduction vs. acetate fermentation—Isotope evidence

Methane oxidation in sediment and water column environments—Isotope evidence

Empirical carbon isotope/maturity relationships for gases from algal kerogens and terrigenous organic matter, based on dry, open-system pyrolysis

Primary cracking of algal and landplant kerogens: Kinetic models of isotope variations in methane, ethane and propane

Maturity related mixing model for methane, ethane and propane, based on carbon isotopes