Forest ecosystems are dynamic, continually changing in response to disturbances. The outcome is largely dependent on the nature of the disturbance and may be beneficial to the forest, such as through gap phase replacement. However, the loss of an entire genus in response to a pest or pathogen (i.e. Dutch elm disease, chestnut blight and hemlock wooly adelgid) may alter the trajectory of forest succession. Since the early 1990s, emerald ash borer (EAB; Agrilus planipennis), an exotic insect pest from Asia, has been spreading throughout eastern forests, leaving behind a wake of dead ash (Fraxinus spp.) trees. Unlike many past pests or pathogens that primarily attack one species, EAB causes mortality in healthy trees of all North American ash species, which are important components of ecosystems ranging from upland hardwood forests to riparian forest corridors to swamp forests. The loss of tens of millions of ash trees has resulted in a cascade of effects on plants, animals, soil, and water. Some effects, such as those on plant growth, are directly related to tree death and resulting canopy gaps; other effects are indirect, including changes in leaf litter composition and the presence of litter-dwelling beetles. The purpose of this session is to bring together researchers from a variety of disciplines in order to present a broad picture of how forests have changed, and are continuing to change, in response to widespread EAB-induced tree mortality. This symposium aims to start a dialogue among researchers from different fields to understand when and how EAB disturbance may lead to fundamental changes in these ecosystems. Research featured in this symposium represents innovative approaches to the study of forest ecosystem disturbance and will include multi-year studies on the impacts of EAB on native and invasive plants, animals, carbon cycling, and soil chemistry. Following the session will be a panel discussion on which kinds of ash ecosystems we expect to have the most extreme long-term changes and what taxa may be most critically impacted.