Warming alters density dependence, energetic fluxes, and population size in a model algae

► We examine the effect of temperature on density dependence in the algae Chlamydomonas reinhardtii. ► Density suppressed metabolic rates, but more severely in the cold treatment. ► Warm populations developed larger cells and grew to a higher density. ► Our results suggest a temperature-dependent life history that alters population dynamics.