Water-use responses of 'living fossil' conifers to CO2 enrichment in a simulated Cretaceous polar environment
Background and Aims During the Mesozoic, the polar regions supported coniferous forests that experienced warm climates, a CO 2 -rich atmosphere and extreme seasonal variations in daylight. How the interaction between the last two factors might have influenced water use of these conifers was investig...
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fthighwire:oai:open-archive.highwire.org:annbot:104/1/179 2023-05-15T15:16:00+02:00 Water-use responses of 'living fossil' conifers to CO2 enrichment in a simulated Cretaceous polar environment Llorens, Laura Osborne, Colin P. Beerling, David J. 2009-07-01 00:00:00.0 text/html http://aob.oxfordjournals.org/cgi/content/short/104/1/179 https://doi.org/10.1093/aob/mcp108 en eng Oxford University Press http://aob.oxfordjournals.org/cgi/content/short/104/1/179 http://dx.doi.org/10.1093/aob/mcp108 Copyright (C) 2009, Oxford University Press ORIGINAL ARTICLES TEXT 2009 fthighwire https://doi.org/10.1093/aob/mcp108 2015-02-28T19:54:07Z Background and Aims During the Mesozoic, the polar regions supported coniferous forests that experienced warm climates, a CO 2 -rich atmosphere and extreme seasonal variations in daylight. How the interaction between the last two factors might have influenced water use of these conifers was investigated. An experimental approach was used to test the following hypotheses: (1) the expected beneficial effects of elevated [CO 2 ] on water-use efficiency (WUE) are reduced or lost during the 24-h light of the high-latitude summer; and (2) elevated [CO 2 ] reduces plant water use over the growing season. Methods Measurements of leaf and whole-plant gas exchange, and leaf-stable carbon isotope composition were made on one evergreen ( Sequoia sempervirens ) and two deciduous ( Metasequoia glyptostroboides and Taxodium distichum ) ‘living fossil’ coniferous species after 3 years' growth in controlled-environment simulated Cretaceous Arctic (69°N) conditions at either ambient (400 µmol mol−1) or elevated (800 µmol mol−1) [CO 2 ]. Key Results Stimulation of whole-plant WUE ( WUE P ) by CO 2 enrichment was maintained over the growing season for the three studied species but this pattern was not reflected in patterns of WUE inferred from leaf-scale gas exchange measurements (i WUE L ) and δ13C of foliage (t WUE L ). This response was driven largely by increased rates of carbon uptake, because there was no overall CO 2 effect on daily whole-plant transpiration or whole-plant water loss integrated over the study period. Seasonal patterns of t WUE L differed from those measured for i WUE L . The results suggest caution against over simplistic interpretations of WUE P based on leaf isotopic composition. Conclusions The data suggest that the efficiency of whole-tree water use may be improved by CO 2 enrichment in a simulated high-latitude environment, but that transpiration is relatively insensitive to atmospheric CO 2 in the living fossil species investigated. Text Arctic HighWire Press (Stanford University) Arctic Annals of Botany 104 1 179 188 |
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HighWire Press (Stanford University) |
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ORIGINAL ARTICLES |
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ORIGINAL ARTICLES Llorens, Laura Osborne, Colin P. Beerling, David J. Water-use responses of 'living fossil' conifers to CO2 enrichment in a simulated Cretaceous polar environment |
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ORIGINAL ARTICLES |
description |
Background and Aims During the Mesozoic, the polar regions supported coniferous forests that experienced warm climates, a CO 2 -rich atmosphere and extreme seasonal variations in daylight. How the interaction between the last two factors might have influenced water use of these conifers was investigated. An experimental approach was used to test the following hypotheses: (1) the expected beneficial effects of elevated [CO 2 ] on water-use efficiency (WUE) are reduced or lost during the 24-h light of the high-latitude summer; and (2) elevated [CO 2 ] reduces plant water use over the growing season. Methods Measurements of leaf and whole-plant gas exchange, and leaf-stable carbon isotope composition were made on one evergreen ( Sequoia sempervirens ) and two deciduous ( Metasequoia glyptostroboides and Taxodium distichum ) ‘living fossil’ coniferous species after 3 years' growth in controlled-environment simulated Cretaceous Arctic (69°N) conditions at either ambient (400 µmol mol−1) or elevated (800 µmol mol−1) [CO 2 ]. Key Results Stimulation of whole-plant WUE ( WUE P ) by CO 2 enrichment was maintained over the growing season for the three studied species but this pattern was not reflected in patterns of WUE inferred from leaf-scale gas exchange measurements (i WUE L ) and δ13C of foliage (t WUE L ). This response was driven largely by increased rates of carbon uptake, because there was no overall CO 2 effect on daily whole-plant transpiration or whole-plant water loss integrated over the study period. Seasonal patterns of t WUE L differed from those measured for i WUE L . The results suggest caution against over simplistic interpretations of WUE P based on leaf isotopic composition. Conclusions The data suggest that the efficiency of whole-tree water use may be improved by CO 2 enrichment in a simulated high-latitude environment, but that transpiration is relatively insensitive to atmospheric CO 2 in the living fossil species investigated. |
format |
Text |
author |
Llorens, Laura Osborne, Colin P. Beerling, David J. |
author_facet |
Llorens, Laura Osborne, Colin P. Beerling, David J. |
author_sort |
Llorens, Laura |
title |
Water-use responses of 'living fossil' conifers to CO2 enrichment in a simulated Cretaceous polar environment |
title_short |
Water-use responses of 'living fossil' conifers to CO2 enrichment in a simulated Cretaceous polar environment |
title_full |
Water-use responses of 'living fossil' conifers to CO2 enrichment in a simulated Cretaceous polar environment |
title_fullStr |
Water-use responses of 'living fossil' conifers to CO2 enrichment in a simulated Cretaceous polar environment |
title_full_unstemmed |
Water-use responses of 'living fossil' conifers to CO2 enrichment in a simulated Cretaceous polar environment |
title_sort |
water-use responses of 'living fossil' conifers to co2 enrichment in a simulated cretaceous polar environment |
publisher |
Oxford University Press |
publishDate |
2009 |
url |
http://aob.oxfordjournals.org/cgi/content/short/104/1/179 https://doi.org/10.1093/aob/mcp108 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
http://aob.oxfordjournals.org/cgi/content/short/104/1/179 http://dx.doi.org/10.1093/aob/mcp108 |
op_rights |
Copyright (C) 2009, Oxford University Press |
op_doi |
https://doi.org/10.1093/aob/mcp108 |
container_title |
Annals of Botany |
container_volume |
104 |
container_issue |
1 |
container_start_page |
179 |
op_container_end_page |
188 |
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1766346317693452288 |