Day‐Night Dynamics in the Organisation of Ant–Plant Interaction Networks in a Brazilian Amazon Rainforest

Interactions between ants and plants bearing extrafloral nectaries (EFN‐bearing plants) represent a classic plant defence strategy that involves a high diversity of species in tropical forests. Several studies have investigated the structuring processes of these ant–plant interactions across spatial and temporal scales. However, surprisingly little is known about how these interactions vary throughout the day. In this study, we investigated daily variations in ant–plant interactions mediated by extrafloral nectaries in a Brazilian tropical forest, using a complex network approach and beta‐diversity analysis of interactions. We sampled these ant–plant interactions in nine 150 × 10 m plots over three periods of the day (morning, afternoon and night). We organised the data from each period into quantitative matrices and combined data from two and three periods to investigate possible increases in network descriptors. We calculated the total beta diversity of interactions, as well as its additive components (species turnover and interaction rewiring), across different pairs of periods. We found that network specialisation and nestedness remained constant throughout the day. However, at night, the networks exhibited reductions in network size, the number of interactions and diversity of interactions. Networks combining data from three periods showed pronounced increases in network size and the number of interactions compared with two‐ and single‐period networks, suggesting temporal niche partitioning associated with extrafloral nectaries. Compositional changes were also detected through the beta diversity of interactions. Greater species turnover and interaction rewiring occurred between the nocturnal period and both diurnal periods. Our results underscore the critical role of the daily temporal scale in structuring these mutualistic networks and reveal how distinct ant foraging strategies partition the resource in time, cautioning against ecological interpretations derived solely from diurnal sampling.