Atmospheric CO2 concentration has fluctuated tremendously over geological time, from as high as 3000 ppm in the lower Devonian to as low as 180 ppm during the Pleistocene. Thus, the current high concentrations are not extremes and can be found in the distant past (25 Ma) as well. This means the earth system has experienced both very high and low CO2 conditions, with very different impacts on fluxes of carbon between land and atmosphere. Through carbon assimilation and respiration as well as afterlife effects via litter decomposition, vegetation plays a pivotal role in modifying these fluxes. As CO2 has an essential function in a number of ecophysiological processes, there exists a strong feedback between the terrestrial biosphere and atmospheric CO2 and climate.
This session aims to bridge the various disciplines working on effects of CO2 fluctuations on the terrestrial earth system. We encourage scientists investigating CO2 interactions with biogeochemical or ecological processes to contribute to our session. We are interested in research on multiple scales: from field experiments to modeling approaches, from local to global scale and from decadal to millennial scale. Also conceptual and methodological contributions are welcome. By bringing together scientists of multiple disciplines we want to highlight recent advances in the field and provide perspectives on future research on variation in CO2 effects on biogeochemical fluxes and ecosystem functioning.