Disturbances that range in magnitude from mild to extreme are important forces structuring plant communities and their ecosystem processes. Nitrogen inputs, fire frequency, and grazing are just some examples of disturbances that alter plant diversity. While some ecosystem processes, such as biomass production, may be enhanced due to disturbance, long-term negative consequences, such as decreased stability, reduced invasion resistance, and resistance to management changes, remain. These disturbances are likely to also impact the microbial communities associated with plants. The microbial communities living on the plant surfaces, inside their tissues, or in the surrounding soil, have important effects on plant fitness and can even impact plant-community level dynamics. Disturbances that would otherwise be relatively mild for plant communities might be amplified by the indirect effects of radical changes in the associated microbes, similar to the invasion of pathogens due to antibiotic disturbances of the gut microbiota. This session seeks to address the questions of: (1) How are plant-associated microbial communities affected by disturbances, many of which may be extreme from their point of view? And (2) What are the consequences of changes in microbial communities for individual plant fitness and plant communities? We are just starting to uncover the effects of microbial disturbances on plant fitness and very little is known about their impact on plant communities as a whole. The impact of disturbances on plant fitness and communities has important implications for food production, habitat structure, conservation, and other services. By identifying the indirect effects of disturbances on plant communities, as mediated through microbial communities, we may be able to highlight paths forward for ameliorating these impacts. In addition, the relatively fast dynamics of microbial communities and their susceptibility to relatively mild disturbances make them ideal study systems for understanding the mechanisms behind community responses to extreme events. This session will knit together a diverse array of systems to explore community dynamics of microbes and their consequences.