Theme 2
Program 3030

Plants in a low CO2 world: proxy development for the Pleistocene plant record and reconstructed feedbacks on the carbon cycle
Program coordinator(s): Dr. W. M. Kurschner
Theme(s): 2
Funding date: 11-dec-09

Changes in atmospheric CO2 directly affect plants because it is a substrate for photosynthesis. While many experiments have documented the growth response of higher plants to elevated CO2, these results are only of limited use for the interpretation of plant growth conditions in the Pleistocene when low CO2 levels (<200 ppmv) prevailed for more than 90% of the time. Terrestrial palaeoclimate reconstructions based on botanical proxies do not account for the physiological effect of low CO2. Likewise the feedbacks on the terrestrial C-cycle are poorly understood. In the present research program we propose a unique combination of growth and decomposition experiments and phylogenetic plant-mediated carbon cycling trait reconstructions with typical elements of the glacial flora at a series of subambient CO2 concentrations. The growth experiments and phylogenetic reconstructions are carried out in order to (1) better understand the acclimation of plants to CO2 starvation and (2) validate botanical and organic geochemical proxies to environmental conditions that persisted during the Pleistocene; (3) quantify the feedback between variations in atmospheric CO2 during the Pleistocene and C cycling traits of plants.

This program contains the following projects:
3031: Validation of botanical and organic geochemical proxies in a low CO2 world
3032: Carbon cycling traits of plants in a low CO2 world: feedback on soils and the atmosphere