Plant breeding systems influence the seasonal dynamics of plant-pollinator networks in a subtropical forest.

Abstract

Temporal dynamics of plant-pollinator interactions inform the mechanisms of community assembly and stability. However, most studies on the dynamics of pollination networks do not consider plant reproductive traits thus offering poor understanding of the mechanism of how networks maintain stable structure under seasonal changes in flower community. We studied seasonal dynamics of pollination networks in a subtropical monsoon forest in China with a clear rainy season (April-September) and dry season (October-March) over 2 consecutive years. We constructed dioecy-ignored networks (combining visitations to dioecious male and female plants by ignoring the difference between dioecious and hermaphroditic plants) and dioecy-considered networks (excluding those visitations that only occurred either on dioecious male or female plants) for eight sampling sessions for each season. Although flower richness and flower abundance were higher in the rainy season than in the dry season, no pronounced seasonal difference was found in network specialization, nestedness and modularity for both networks. There were only significant differences in plant communityrobustness and pollinator specialization between seasons for dioecy-considered networks but not for dioecy-ignored networks. Furthermore, we found the flower abundance of dioecious and hermaphrodite plants mostly showed trade-off variation between rainy and dry seasons. Our results suggest various plant reproductive traits affect the temporal dynamics of pollination networks, which should be considered for conservation of plant-pollinator interactions in forest communities.