Modeling 13 C discrimination in tree rings
Annual variations from 1877 to 1995 in tree-ring alpha-cellulose C-13/C-12 isotopic ratios for four subarctic Pinus sylvestris trees were determined, and, in conjunction with a recent record of atmospheric (CO 2 )-C-13/(CO 2 )-C-12 ratios, the historical pattern of photosynthetic isotope discriminat...
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ftpubman:oai:pure.mpg.de:item_1690753 2023-08-27T04:12:16+02:00 Modeling 13 C discrimination in tree rings Berninger, F. Sonninen, E. Aalto, T. Lloyd, J. 2000 application/octet-stream http://hdl.handle.net/11858/00-001M-0000-000E-CC48-8 http://hdl.handle.net/11858/00-001M-0000-000E-CC47-A unknown info:eu-repo/semantics/altIdentifier/doi/10.1029/1999GB900064 http://hdl.handle.net/11858/00-001M-0000-000E-CC48-8 http://hdl.handle.net/11858/00-001M-0000-000E-CC47-A Global Biogeochemical Cycles info:eu-repo/semantics/article 2000 ftpubman https://doi.org/10.1029/1999GB900064 2023-08-02T01:03:17Z Annual variations from 1877 to 1995 in tree-ring alpha-cellulose C-13/C-12 isotopic ratios for four subarctic Pinus sylvestris trees were determined, and, in conjunction with a recent record of atmospheric (CO 2 )-C-13/(CO 2 )-C-12 ratios, the historical pattern of photosynthetic isotope discrimination, Delta(13)C, was evaluated. Year-to-year variability in Delta(13)C has been as much as 1.5 parts per thousand with the period 1900-1920 showing an extended period of unusually high photosynthetic discriminations. The summers during these years were, on average, unusually cold. Since 1920 a long term trend of increasing Delta(13)C of similar to 0.016 parts per thousand yr(-1) is inferred. We compared measured Delta(13)C with those predicted on the basis of the theoretical relationship between Delta(13)C and the ratio of substomatal to ambient CO 2 concentration, C-i/C-a using mechanistic equations for chloroplast biochemistry coupled with a stomatal conductance model. Two variations of a nonlinear optimal-regulation stomatal conductance model were compared. Although both models were based on the assumption that stomata serve to minimize the average transpiration rate for a given average rate of CO 2 assimilation, one version of the model incorporated reductions in stomatal conductance in response to recent increases in atmospheric CO 2 concentrations and the other did not. The CO 2 sensitive stomatal model failed to describe the long-term increase in C-13 discrimination, especially after 1950. The insensitive model gave good agreement, suggesting that an observed increase in subarctic Pinus sylvestris Delta(13)C since 1920 is attributable to recent increases in atmospheric CO 2 concentrations with subsequent increases in the ratio of substomatal to ambient CO 2 concentrations. The model was also capable of accounting for high frequency (year-to-year) variations in Delta(13)C, these differences being attributable to year-to-year fluctuations in the average leaf-to-air vapor pressure difference affecting stomatal ... Article in Journal/Newspaper Subarctic Max Planck Society: MPG.PuRe Global Biogeochemical Cycles 14 1 213 223 |
institution |
Open Polar |
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Max Planck Society: MPG.PuRe |
op_collection_id |
ftpubman |
language |
unknown |
description |
Annual variations from 1877 to 1995 in tree-ring alpha-cellulose C-13/C-12 isotopic ratios for four subarctic Pinus sylvestris trees were determined, and, in conjunction with a recent record of atmospheric (CO 2 )-C-13/(CO 2 )-C-12 ratios, the historical pattern of photosynthetic isotope discrimination, Delta(13)C, was evaluated. Year-to-year variability in Delta(13)C has been as much as 1.5 parts per thousand with the period 1900-1920 showing an extended period of unusually high photosynthetic discriminations. The summers during these years were, on average, unusually cold. Since 1920 a long term trend of increasing Delta(13)C of similar to 0.016 parts per thousand yr(-1) is inferred. We compared measured Delta(13)C with those predicted on the basis of the theoretical relationship between Delta(13)C and the ratio of substomatal to ambient CO 2 concentration, C-i/C-a using mechanistic equations for chloroplast biochemistry coupled with a stomatal conductance model. Two variations of a nonlinear optimal-regulation stomatal conductance model were compared. Although both models were based on the assumption that stomata serve to minimize the average transpiration rate for a given average rate of CO 2 assimilation, one version of the model incorporated reductions in stomatal conductance in response to recent increases in atmospheric CO 2 concentrations and the other did not. The CO 2 sensitive stomatal model failed to describe the long-term increase in C-13 discrimination, especially after 1950. The insensitive model gave good agreement, suggesting that an observed increase in subarctic Pinus sylvestris Delta(13)C since 1920 is attributable to recent increases in atmospheric CO 2 concentrations with subsequent increases in the ratio of substomatal to ambient CO 2 concentrations. The model was also capable of accounting for high frequency (year-to-year) variations in Delta(13)C, these differences being attributable to year-to-year fluctuations in the average leaf-to-air vapor pressure difference affecting stomatal ... |
format |
Article in Journal/Newspaper |
author |
Berninger, F. Sonninen, E. Aalto, T. Lloyd, J. |
spellingShingle |
Berninger, F. Sonninen, E. Aalto, T. Lloyd, J. Modeling 13 C discrimination in tree rings |
author_facet |
Berninger, F. Sonninen, E. Aalto, T. Lloyd, J. |
author_sort |
Berninger, F. |
title |
Modeling 13 C discrimination in tree rings |
title_short |
Modeling 13 C discrimination in tree rings |
title_full |
Modeling 13 C discrimination in tree rings |
title_fullStr |
Modeling 13 C discrimination in tree rings |
title_full_unstemmed |
Modeling 13 C discrimination in tree rings |
title_sort |
modeling 13 c discrimination in tree rings |
publishDate |
2000 |
url |
http://hdl.handle.net/11858/00-001M-0000-000E-CC48-8 http://hdl.handle.net/11858/00-001M-0000-000E-CC47-A |
genre |
Subarctic |
genre_facet |
Subarctic |
op_source |
Global Biogeochemical Cycles |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/1999GB900064 http://hdl.handle.net/11858/00-001M-0000-000E-CC48-8 http://hdl.handle.net/11858/00-001M-0000-000E-CC47-A |
op_doi |
https://doi.org/10.1029/1999GB900064 |
container_title |
Global Biogeochemical Cycles |
container_volume |
14 |
container_issue |
1 |
container_start_page |
213 |
op_container_end_page |
223 |
_version_ |
1775356227992158208 |