作者: Benjamin J. Fletcher , David J. Beerling , Stuart J. Brentnall , Dana L. Royer
DOI: 10.1029/2005GB002495
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摘要: [1] Biological and geochemical CO2 proxies provide critical constraints on understanding the role of atmospheric in driving climate change during Earth history. As no single existing proxy is without its limitations, there a clear need for new approaches to reconstructing past concentrations. Here we develop pre-Quaternary based stable carbon isotope composition (δ13C) astomatous land plants. In series CO2-controlled laboratory experiments, show that discrimination (Δ13C) range bryophyte (liverwort moss) species increases with across 375 6000 ppm. Separate experiments establish variations growth temperature, water content substrate type have minor impacts Δ13C liverworts but not mosses, indicating greater potential faithfully record CO2. A mechanistic model calculating concentrations from (White et al., 1994) extended calibrated using our experimental results. The fossil changes investigated by analyzing δ13C specimens collected Alexander Island, Antarctica dating “greenhouse” world mid-Cretaceous. Our analysis isotopic yield mid-Cretaceous 1000–1400 ppm, general agreement independent data long-term cycle models. exceptionally long evolutionary history bryophytes offers possibility back mid-Ordovician, pre-dating all currently used quantitative proxies.