Seasonal structure of interactions enhances multidimensional stability of mutualistic networks

Community ecologists have made great advances in understanding how natural communities can be both diverse and stable by studying communities as interaction networks. However, focus has been on interaction networks aggregated over time, neglecting the consequences of the seasonal organization of interactions (hereafter 'seasonal structure') for community stability. Here, we extended previous theoretical findings on the topic in two ways: (i) by integrating empirical seasonal structure of 11 plant-hummingbird communities into dynamic models, and (ii) by tackling multiple facets of network stability together. We show that, in a competition context, seasonal structure enhances community stability by allowing diverse and resilient communities while preserving their robustness to species extinctions. The positive effects of empirical seasonal structure on network stability vanished when using randomized seasonal structures, suggesting that eco-evolutionary dynamics produce stabilizing seasonal structures. We also show that the effects of seasonal structure on community stability are mainly mediated by changes in network structure and productivity, suggesting that the seasonal structure of a community is an important and yet neglected aspect in the diversity-stability and diversity-productivity debates.

Automated summary

Community ecologists have made significant progress in understanding the relationship between diversity and stability in natural communities by studying interaction networks. However, they have generally neglected the effects of seasonal organization of interactions on community stability. This study extends previous theoretical findings by incorporating empirical seasonal structures into dynamic models and examining multiple facets of network stability. The results demonstrate that the seasonal structure enhances community stability by allowing for diverse and resilient communities while preserving robustness to species extinctions. The effects of seasonal structure on stability are mediated by changes in network structure and productivity, emphasizing the importance of considering seasonal structure in the diversity-stability and diversity-productivity debates.