Proximity to honeybee hives drives floral visitor composition and specialization in an arid ecosystem

Abstract

Agricultural intensification driven by high demand for food and honey production has encouraged the use of managed pollinators, which may affect wild species. When introduced at high densities, honeybees can increase competition for floral resources with wild pollinators and alter their visits to flowers, ultimately affecting both pollinators and wild plants. We experimentally investigated how the introduction of managed honeybee hives, an invasive species, influences the structure of plant-pollinator networks in an arid ecosystem in Villavicencio Nature Reserve, Argentina. To this end, we built two types of networks in paired sites near (200 m) and far (1000 m) from managed hives: one based on censuses of flower visits and the other based on pollen samples from nests of solitary wood-nesting bees. The proximity to man-aged honeybee hives influenced the composition and specialization of plant-pollinator interactions. Implications for insect conservation: our results contribute to the understanding of the ecological consequences of managing an invasive bee species on the structure of plant-pollinator networks, and demonstrate that even a small number of hives installed for a short period of the year can alter the wild pollinator community and their flower visitation patterns in an arid ecosystem. Given the significance of nature reserves in conserving biodiversity, we strongly recommend caution when considering the introduction of managed honeybee hives into protected areas.