Reports

Paleoatmospheric Signatures in Neogene Fossil Leaves

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Science  18 Jun 1993:
Vol. 260, Issue 5115, pp. 1788-1790
DOI: 10.1126/science.260.5115.1788

Abstract

An increase in the atmospheric carbon dioxide (CO2) concentration results in a decrease in the number of leaf stomata. This relation is known both from historical observations of vegetation over the past 200 years and from experimental manipulations of microenvironments. Evidence from stomatal frequencies of fossil Quercus petraea leaves indicates that this relation can be applied as a bioindicator for changes in paleoatmospheric CO2 concentrations during the last 10 million years. The data suggest that late Neogene CO2 concentrations fluctuated between about 280 and 370 parts per million by volume.