Stomatal index responses of Agrostis canina to CO2 and sulphur dioxide: implications for palaeo-[CO2] using the stomatal proxy.
New Phytol
; 188(3): 845-55, 2010 Nov.
Article
en En
| MEDLINE
| ID: mdl-20704659
ABSTRACT
⢠Stomatal index values of fossil plants are widely used in reconstructing palaeo-[CO(2)]. This depends upon the assumption that the stomatal index is determined by the atmospheric concentration of CO(2) ([CO(2)]). This study investigates whether fumigation with, and resistance to, sulphur dioxide (SO(2)) induces a reduction in the stomatal index that may affect stomatal reconstructions of palaeo-[CO(2)] coinciding with episodes of global-scale volcanism. ⢠Agrostis canina from Mefite di Ansanto, Italy, grow in atmospheres of elevated-[CO(2)], SO(2) and hydrogen sulphide (H(2)S). Mefite A. canina were compared with a control population in a 'common-garden' experiment and a controlled-environment study under elevated-[CO(2)] and SO(2) fumigation. ⢠In A. canina, resistance to toxic volcanic gases is not associated with reduced stomatal index, and fumigation with SO(2) does not cause a decrease in stomatal initiation. The two populations of A. canina analyzed in this study exhibit different stomatal index-[CO(2)] 'responses', with control plants showing a reduction in stomatal index and Mefite plants showing no response. ⢠Stomatal reconstructions of palaeo-[CO(2)] during past episodes of global-scale volcanism probably reflect atmospheric [CO(2)] and not [SO(2)]. The lack of a reduction in the stomatal index in response to elevated [CO(2)] in the Mefite plants, suggests that resistance to toxic gases and/or long-term growth at high [CO(2)] reduces, or negates, sensitivity of the stomatal index-[CO(2)] relationship, or that stomatal index-[CO(2)] in the Mefite plants is attuned to [CO(2)] fluctuations at much higher concentrations.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Dióxido de Azufre
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Dióxido de Carbono
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Erupciones Volcánicas
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Agrostis
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Sulfuro de Hidrógeno
País/Región como asunto:
Europa
Idioma:
En
Revista:
New Phytol
Asunto de la revista:
BOTANICA
Año:
2010
Tipo del documento:
Article
País de afiliación:
Irlanda