Impact of climate warming on phenological asynchrony of plankton dynamics across Europe

Climate warming alters the seasonal timing of biological events. This raises concerns that species-specific responses to warming may de-synchronize co-evolved consumer-resource phenologies, resulting in trophic mismatch and altered ecosystem dynamics. Here we explore effects of warming on the temporal coherence of two key phenological events in lakes across Europe: The onset of the phytoplankton spring bloom and the spring/summer maximum of the grazer Daphnia. Simulation of 1,891,744 lake years revealed that, under the current climate, the phenological delay between the two events varies greatly (20-190 days) across lake types and geographic locations. Warming moves both phenological events forward in time and can predictably lengthen or shorten the delay between them by up to 60 days. Our findings expose large extant variation in phenological synchrony of planktonic organisms, provide quantitative predictions of its dependence on physical lake properties and geographic location, and highlight research needs concerning its ecological consequences.