La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Ecosystem CO2 starvation and terrestrial silicate weathering: mechanisms and global-scale quantification during the late Miocene
Auteurs :	David J. Beerling, Auteur ; Lyla L. Taylor, Auteur ; Catherine D. C. Bradshaw, Auteur ; Daniel J. Lunt, Auteur ; Paul J. Valdes, Auteur ; Steven A. Banwart, Auteur ; Mark Pagani, Auteur ; Jonathan R. Leake, Auteur
Type de document :	Article
Dans :	Journal of Ecology (100(1) JAN 2012)
Article en page(s) :	31-41
Langues:	Anglais
Résumé :	1. The relative constancy of the lower limit on Earths atmospheric CO2 concentration ([CO2]a) during major tectonic episodes over the final 24 million years (Ma) of the Cenozoic is surprising because they are expected to draw-down [CO2]a by enhancing chemical weathering and carbonate deposition on the seafloor. That [CO2]a did not drop to extremely low values suggests the existence of feedback mechanisms that slow silicate weathering as [CO2]a declines. One proposed mechanism is a negative feedback mediated through CO2 starvation of land plants in active orogenic regions compromising the efficiency of the primary carboxylating enzyme in C3 plants (Rubisco) and diminishing productivity and terrestrial weathering.

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