Microorganisms living in soil are usually well adapted to environmental fluctuations, but are challenged by unfavourable conditions related to the food supply combined to variations in temperature, soil moisture, electron acceptor availability, predators, viruses, and mechanical forces. Despite being well-adapted, we do not know how microbial metabolism and community composition will be affected by changes in these conditions. In fact, climate scenarios predict not only continued global warming but also strong changes in temperature and precipitation. At the same time, we have seen major shifts in land use with an increase in large-scale agricultural practices and urbanization. Both climate and land-use change alter the metabolism of soil organisms and soil biodiversity from the micro-scale (bacteria, fungi, archea, protozoa, virus) to the macro-scale (soil animals, earthworms, arthropods, nematodes, etc.). This can have significant ramifications for soil functions including soils’ ability to store organic carbon, support agriculture and conserve biodiversity.
This session collects experimental and modelling studies to understand microbial life, propagation, communication, growth, functioning, adaptations, maintenance metabolism, death, and necromass stabilisation in soil. Plant-microbe interactions and soil biota contribution to carbon sequestrations and crop production are also considered. In this broad context, this session also presents contributions on carbon use efficiency (CUE=ratio of biomass production over carbon substrate consumption) as an indicator or microbial metabolism. These include CUE estimation in soil using advanced methods – isotope labelling, kinetic studies, isothermal calorimetry, and approaches disclosing the effect of microbial community composition and activity on CUE – and modelling studies. A major common challenge in all these areas of soil ecology is how to scale observations and model concepts from organism and communities to soil profiles, ecosystems and finally to scales relevant to management and policy, all the way to the global scale. We thus welcome innovative and interdisciplinary studies that are pushing the field of soil ecology from the understanding of ecological and biogeochemical processes in soils to addressing global sustainability issues.