CIFRes

Carbon Isotope Fractionation during RESpiration: Mechanisms and environmental drivers

Contact
Roland A. Werner

Project Members
Rolf Siegwolf (PSI)
Marco Lehmann

Timeplan
2011-2013

Context

Global warming will change precipitation patterns leading to an increase of frequency and magnitude of drought events. This deficit water supply will effect carbon uptake (photosynthesis) and carbon loss (respiration) by plants in terrestrial ecosystems. Measurement of net ecosystem exchange of CO₂ by eddy-covariance techniques does not allow to address assimilation and respiration fluxes separately. Partitioning and quantification of the two opposite carbon dioxide fluxes at the ecosystem scale by the use of stable isotopes is complicated (among others) by the reported variability of δ¹³C of respired CO₂ (CO_2Res). In this SNF-funded project, we will examine the metabolic system behind the carbon isotope fractionation during respiration.

Objectives

Within CIFRes, we plan to:

• identify the impacts of environmental drivers on the carbon isotopic signature of CO_2Res.

• determine the mechanisms and processes influencing the carbon isotopic signature of CO_2Res.

• obtain insight into the processes behind isotope fractionation during respiration, thereby possibly allowing to distinguish between the impact of isotope effects on respirative enzymes and the use of different substrates to gain CO_2Res.

Publications