Understanding Ecological Forces Governing Assembly and Function of Microbial Communities


A complex, dynamic, and interactive set of ecological forces governs the assembly of a microbial community in any given environment. The composition and structure of the resulting community in turn controls functional biological processes performed at the site, influencing biogeochemical cycling of nutrients, transport of contaminants, and interactions with other organisms. As such, understanding the rules that govern assembly and successional change of microbial communities in different types of environments is critical to predicting changes in ecosystem-scale processes under changing environmental conditions. In a new study by Lawrence Berkeley National Laboratory’s ENIGMA Science Focus Area, researchers examined mechanisms driving microbial community assembly and succession in an experimentally manipulated groundwater ecosystem. The team tested a set of theoretical models to compare the relative importance of stochastic (i.e., random) and deterministic processes in shaping community structure after an environmental change (in this case, the addition of nutrients). Community assembly and succession were found to be driven by a dynamic, time-dependent interaction of stochastic and deterministic processes, with stochastic forces dominating. By identifying the mechanisms controlling microbial community assembly and succession, this study makes an important contribution to the mechanistic understanding essential for a predictive microbial ecology of natural and managed ecosystems.


Zhou, J., Y. Deng, P. Zhang, K. Xue, Y. Liang, J. D. Van Nostrand, Y. Yang, Z. He, L. Wu, D. A. Stahl, T. C. Hazen, J. M. Tiedje, and A. P. Arkin. 2014. “Stochasticity, Succession, and Environmental Perturbations in a Fluidic Ecosystem,” Proceedings of the National Academy of Sciences (USA), DOI: 10.1073/pnas.1324044111.