Accurate predictions of soil respiration rates are crucial to the predictive modelling of regional and global ecosystem carbon budgets. The challenge arises, in part, because CO2 efflux comprises a range of sources that are difficult to separate using conventional methods. The sources include autotrophic contributions from roots and rhizosphere, as well as heterotrophic decomposition of soil organic matter of different ages and ‘qualities’ referring to the bonding structure of complex soil organic matter molecules. Over the past decade, there have been many advances in studying soil carbon dynamics, including improved methods in direct soil CO2 efflux measurements and C turnover in soils using isotopic tracers, as well as approaches to identify heterotrophic soil communities and their seasonal dynamics. In this session, we invite contributions that examine measurements and/or models of either total or partitioned flux of CO2 from soils. In particular, we encourage studies that investigate relationships between ecosystem productivity and autotrophic activity, microbial dynamics, C turnover in soils, and respiration across space and time, especially those studies that employ novel methodologies that advance the mechanistic understanding of respiration. Submissions that attempt a synthesis across a range of spatial and temporal scales are particularly encouraged, while studies aimed at process understanding at a particular scale are equally welcomed.

Confirmed keynote speakers: Alf Ekblad (Örebro University, Sweden) and Michael Bahn (Univ. Innsbruck, Austria)