Towards the general mechanistic prediction of community dynamics

1. "What controls the distribution and abundance of organisms"? This question, at the heart of the dynamics of ecological communities, would have been familiar to the earliest ecologists. Having lain effectively abandoned for many years, community dynamics today is a vibrant research topic of great conceptual interest with practical import for conservation, ecological management, ecosystem services and the responses of ecological communities to climate change.2. We describe how modern coexistence theory can be used to predict community dynamics through the use of demography. We explore the challenges that limit the deployment of this demographic framework, and the tools from phylogenetic and functional ecology that have been used to surmount them.3. Finding existing tools not altogether sufficient, we propose the use of "hard" functional traits and physiological tolerances of environmental conditions and low resource availability to extend the demographic framework so that the dynamics of a broader range of ecological communities can be accurately predicted.4. We illustrate these new approaches with two case studies. Given the urgent need to accurately forecast the dynamics of ecological communities, we hope that many ecologists will adopt these tools.