Impact of mesophyll diffusion on estimated global land CO2 fertilization.
Proc Natl Acad Sci U S A
; 111(44): 15774-9, 2014 Nov 04.
Article
en En
| MEDLINE
| ID: mdl-25313079
ABSTRACT
In C3 plants, CO2 concentrations drop considerably along mesophyll diffusion pathways from substomatal cavities to chloroplasts where CO2 assimilation occurs. Global carbon cycle models have not explicitly represented this internal drawdown and therefore overestimate CO2 available for carboxylation and underestimate photosynthetic responsiveness to atmospheric CO2. An explicit consideration of mesophyll diffusion increases the modeled cumulative CO2 fertilization effect (CFE) for global gross primary production (GPP) from 915 to 1,057 PgC for the period of 1901-2010. This increase represents a 16% correction, which is large enough to explain the persistent overestimation of growth rates of historical atmospheric CO2 by Earth system models. Without this correction, the CFE for global GPP is underestimated by 0.05 PgC/y/ppm. This finding implies that the contemporary terrestrial biosphere is more CO2 limited than previously thought.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plantas
/
Atmósfera
/
Dióxido de Carbono
/
Cloroplastos
/
Modelos Teóricos
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2014
Tipo del documento:
Article