Microbial modulators and mechanisms of soil carbon storage

This chapter aims to provide a mechanistic understanding of the role microbes play in soil carbon (C) storage and propose pathways to include this data to modify existing ecological models. We found that the structure and function of soil microbial communities are controlled by complex interactions of biotic and abiotic site factors, while structural variations in soil microbial communities modulate transformation and/or turnover of soil C. We also demonstrated that inclusion of different microbial groups provides better predictions for different enzymatic activities involved in C degradation. Soil bacteria differ in their survival strategies and ability to influence the terrestrial C pool. We found that the effects of soil management practices of soil C turnover are modulated by the soil aggregate sizesand their associated microbial communities. The control of soil microbial communities on soil C turnover is much more pronounced in smaller sized aggregates. Altogether we demonstrate that soil microbial communities modulate soil C turnover from regional to global scale. Based on our findings, we propose that incorporation of microbial taxonomical and functional information in Earthecosystem models will reduce uncertainty in model structure as these will represent temporal stability and adaptive responses of microbial communities and their interactions with the environment, which are critical considerations as we face environmental variations and rates of change.