Whether species interactions are static or change over time has wide-reaching ecological and evolutionary consequences. However, species interaction networks are typically constructed from temporally aggregated interaction data, thereby implicitly assuming that interactions are fixed. This approach has advanced our understanding of communities, but it obscures the timescale at which interactions form (or dissolve) and the drivers and consequences of such dynamics. We address this knowledge gap by quantifying the within-season turnover of plant–pollinator interactions from weekly censuses across 3 years in a subalpine ecosystem. Week-to-week turnover of interactions (1) was high, (2) followed a consistent seasonal progression in all years of study and (3) was dominated by interaction rewiring (the reassembly of interactions among species). Simulation models revealed that species’ phenologies and relative abundances constrained both total interaction turnover and rewiring. Our findings reveal the diversity of species interactions that may be missed when the temporal dynamics of networks are ignored.

CaraDonna_Interaction_Turnover_All_Years_RMBLData from Table S4. Beta-diversity (turnover) values for each week-to-week transition for all turnover metrics (including Bray-Curtis interaction turnover) for each year of study. All notation is included in the main text of the manuscript.CaraDonna_Interaction_Turnover_simulation_models_and_observed_All_Years_RMBLData generated from probability-based simulation models to explore potential ecological factors that may constrain within-season interaction turnover. Details of simulation models and subsequent analyses are provided in the main text of the manuscript.