Increasing synchrony of annual river‐flood peaks and growing season in Europe

y In a changing climate, time sensitive ecological interactions such as pollination and predation are vulnerable to temporal mismatch with direct consequences for ecosystem functioning. It is not known if synchrony and asynchrony of ecological and physical processes such as flood disturbance and plant phenology may similarly be affected by climate change. Here, by spatially merging temperature and flood peak data, we show for the first time that in Central and Eastern Europe, annual river flood peaks increasingly occur within the thermal growing season. This is due to the combined effect of earlier spring onsets and later flood peaks. Such increased physical-phenological synchrony may especially impact river biogeomorphology and riparian floodplain ecosystem functioning through uprooting of seedlings and increased hydraulic roughness during major flood events.