Ecological relevance of carbon isotope fractionation during dark respiration

• Applicant: Professorin Dr. Christiane Werner
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: from 2009 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 157216006

A functional understanding of biosphere/atmosphere CO2 exchange is important regarding global climate change. Investigation of ecosystem assimilatory and respiratory fluxes and associated carbon pools has thus, become a major goal in ecosystem research world-wide. Stable carbon isotope ratios δ13C provide a powerful diagnostic tool to identify the underiying mechanisms driving ecosystem respiratory processes. A thorough understanding of isotopic fractionation during dark respiration in plants has been achieved on the physiological scale, however much iess is known about its impact at larger scales. It has become evident that the extent of this fractionation varies substantially among different functional plant groups but experimental proof on the mechanisms is still lacking. This project aims to close the gap between recent advances on,mechanisms of fractionation during dark respiration and its ecological significance by combining metabolic, whole-plant and ecosystem approaches. This study will focus on the analysis of short-term variations of respiratory δ13Cres in selected functional groups considering diurnal dynamics of metabolite pools in leaves, shoots and roots. Possible implications of diurnal dynamics in δ13Cres at larger scales will be assessed by evaluating the processes at the leat whole-plant and the ecosystem scale using a component mass balance approach in a natural Mediterranean ecosystem. Understanding the processes behind the dynamics of δ13C of ecosystem respiration has significant implications for the evaluation of ecosystem response to global change.

• DFG Programme: Research Grants