Temporal synchrony between floral volatile organic compounds and pollinator turnover in dynamic plant-pollinator networks

Abstract

Floral volatile organic compounds (VOCs) are critical for mediating plant-pollinator interactions at the community level. Both plant-pollinator interactions and floral VOC emissions vary over time, resulting in dynamic changes in plant-pollinator and plant-VOC networks that affect community stability. However, the relationship between variation in floral VOCs and pollinator communities at the community level, and whether the two network types exhibit congruent temporal patterns, remain unclear. We conducted a year-long, community-level investigation, constructing temporal plant-pollinator and plant-VOC networks. We examined the relationship between the structures of plant-pollinator and plant-VOC networks and interactions between specific VOC classes and pollinator groups within distinct network modules. Key network metrics were positively correlated across plant-pollinator and plant-VOC networks, indicating congruent dynamics. Monthly shifts in pollinator composition were tightly coupled with changes in floral VOC profiles, indicating that a broader chemical signaling breadth may serve as potential driver of plant generalization by facilitating interactions with a wider range of pollinators. Modular organization of both networks was highly dynamic, with plant species displaying considerable flexibility in changing their pollinators, emitted floral VOCs, affiliations among network modules. However, associations between certain VOC classes and specific pollinator groups were highly context-dependent, varying in both strength and direction across months, which highlights the challenge in definitively linking particular VOCs to pollinator taxa. This study for the first time presents simultaneous dataset of floral VOCs and their associated pollinators for multiple plant species at community level, which is inspiring for elucidating the broader ecological roles of floral VOCs across landscape scales.