Towards a predictive understanding of belowground process responses to climate change: have we moved any closer?

Abstract

Summary 1. Belowground processes, including root production and exudation, microbial activity and community dynamics, and biogeochemical cycling interact to help regulate climate change. Feedbacks associated with these processes, such as warming-enhanced decomposition rates, give rise to major uncertainties in predictions of future climate. 2. Uncertainties associated with these processes are more likely to be reduced if two key challenges can be met: increasing interdisciplinarity among researchers, and measuring belowground ecosystem structure and function at relevant spatial and temporal scales. For instance, recognizing the relationship between belowground primary production and soil respiration enhances modelling of global-scale C cycle temperature responses. At the opposite end of the spectrum, applying genomic techniques at the scale of microns improves mechanistic understanding of root‐microbe interactions. 3. Progress has been made in understanding interactions of belowground processes with climate change, although challenges remain. We highlight some of these advances and provide directions for key research needs in this Special Feature of Functional Ecology, which results from a symposium that was convened at the Soil Science Society of America National Meeting in November, 2006.