Title. Microbial ecosystem development: is it predictable and how does it respond to perturbations?.

Summary. Advances in DNA sequencing technology are revealing the vast diversity and complexity of microbial communities in the natural environment, but many of the fundamental principles governing how these communities assemble and function remain unclear. We are trying to decipher some of these principles using a laboratory microcosm system consisting of self-sustaining nutrient-cycling microbial communities made from pond sediment and water, together with mathematical models. I will first describe an investigation of the reproducibility of community development in these microcosms, and then discuss how these nutrient-cycling communities respond to environmental perturbations.