Coevolution and temporal dynamics of species interactions shape species coexistence

Evolutionary and ecological forces shape species coexistence, but how different ecological mechanisms drive coevolutionary dynamics remains poorly understood. Focusing on mutualistic communities, we explore how morphological and phenological trait matching can shape the coevolution of species traits, influence the evolutionary trajectories at the community level, and determine community stability. Using in silico experiments, we first show that because phenological traits can decouple interactions in time, their coevolutionary dynamics led to the emergence of interaction motifs promoting facilitation over competition. In contrast, coevolution driven by morphological traits led to poorly structured networks with higher connectance. As a consequence, phenological coevolution increased the ecological stability of the community, relative to those coevolved based on morphology, and dampened the diversity-stability trade-off observed in morphologically coevolved communities. Next, by using 17 empirical pollination networks, we show that phenological motifs promoting facilitation were abundant in natural communities, and that as predicted by the theoretical models, the phenological structure in species interactions was a major determinant of the structural stability of these empirical communities. These results show that modelling explicitly the basic mechanisms determining species interactions is crucial to understand how species coevolve, and the ecological properties emerging at the community level, such as community structure and stability.