A7

While many studies have addressed changes in community composition in response to environmental change (e.g. Harpole et al. 2016), few studies have looked at the reversibility of the community after the environmental change has been reverted. Aquatic microcosms provide tractable systems for such experiments, as they allow to replicate communities in large numbers and to experimentally manipulate the communities themselves as well as their environments (Cadotte et al. 2005). In this subproject, we address some of the main R3 questions using microcosm communities consisting of multiple unicellular algae to test their responses to different environmental changes, their reversibility after the environmental variable has returned to its previous state, and how this is affected by a changing baseline (e.g. invasion by another species).