Stomatal Density and Index of Fossil Plants Track Atmospheric Carbon Dioxide in the Palaeozoic
It has been demonstrated that the leaves of a range of forest tree species have responded to the rising concentration of atmospheric CO 2 over the last 200 years by a decrease in both stomatal density and stomatal index. This response has also been demonstrated experimentally by growing plants under...
| Published in: | Annals of Botany |
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| Main Authors: | , |
| Format: | Text |
| Language: | English |
| Published: |
Oxford University Press
1995
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| Subjects: | |
| Online Access: | http://aob.oxfordjournals.org/cgi/content/short/76/4/389 https://doi.org/10.1006/anbo.1995.1112 |
| Summary: | It has been demonstrated that the leaves of a range of forest tree species have responded to the rising concentration of atmospheric CO 2 over the last 200 years by a decrease in both stomatal density and stomatal index. This response has also been demonstrated experimentally by growing plants under elevated CO 2 concentrations. Investigation of Quaternary fossil leaves has shown a corresponding stomatal response to changing CO 2 concentrations through a glacial-interglacial cycle, as revealed by ice core data. Tertiary leaves show a similar pattern of stomatal density change, using palynological evidence of palaeo-temperature as a proxy measure of CO 2 concentration. The present work extends this approach into the Palaeozoic fossil plant record. The stomatal density and index of Early Devonian, Carboniferous and Early Permian plants has been investigated, to test for any relationship that they may show with the changes in atmospheric CO 2 concentration, derived from physical evidence, over that period. Observed changes in the stomatal data give support to the suggestion from physical evidence, that atmospheric CO 2 concentrations fell from an Early Devonian high of 10-12 times its present value, to one comparable to that of the present day by the end of the Carboniferous. These results suggest that stomatal density of fossil leaves has potential value for assessing changes in atmospheric CO 2 concentration through geological time. Copyright 1995, 1999 Academic Press |
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