Abstract
<jats:p> Ecological communities can exhibit transient amplification after disturbance even if asymptotically stable, yet how environmental change reshapes these short-term responses in real food webs remains unclear. We combined four decades of monthly plankton observations from nine Swiss lakes with a food-web model to quantify effects of warming and oligotrophication on two transient properties: reactivity (instantaneous sensitivity to small disturbances) and the time to peak response ( <jats:italic>t</jats:italic> <jats:sub>max</jats:sub> ). Across lakes, community states lie in an asymptotically stable yet reactive regime. Warmer conditions consistently increased reactivity and lengthened <jats:italic>t</jats:italic> <jats:sub>max</jats:sub> ; after accounting for oligotrophication, a 1 °C rise in mean temperature corresponded to ~ 10 higher reactivity on average. Linking month-to-month variation in transient metrics to guild biomass showed that reactivity covaried strongly with consumer biomass, especially large herbivores, whereas <jats:italic>t</jats:italic> <jats:sub>max</jats:sub> was most associated with predator biomass, a pattern consistent with metabolic-scaling predictions from thermal ecology. The central warming-reactivity association was preserved when we made the bioenergetic parameters themselves temperature-dependent through Boltzmann-Arrhenius scaling. Warming therefore systematically boosted transient sensitivity in these lake food webs via shifts in consumer and predator biomass. </jats:p>