SUPPORTING INFORMATION 5.12

1. The Qinling Mountains are rich in vegetation and diverse in pollinating insects. In the past few decades, both the population and diversity of bees in the Qinling Mountains and surrounding areas are decreasing dramaticallydue to the effects of Apis mellifera, with cascading impacts on community structure and ecosystem stability in the region.2. In order to improve the protection of native bees in the natural and agricultural landscape of the Qinling Mountains and its surrounding areas, we investigated 33 sampling sites in 3 habitats (forest, forest-agriculture ecotones and farmland).3. We used a generalized linear mixing model, t-test and other data analysis methods to explore the impact mechanisms of Apis mellifera on local pollinator bee diversity, abundance, and the pollination network in different habitats in these region areas.4. The results show that ① Apis mellifera has a significant negative effect on the abundance and richness of wild bees, while the Apis cerana abundance is also affected by beekeeping conditions; ② There arealso significant negative effectsof Apis melliferaon the community structure of pollinatorbees in the Qinling Mountains and its surrounding areas: the ShannonWiener diversity index, Pielou evenness index and Margalef richness index of bee communities at sites with Apis mellifera influence were significantly lower than those at sites without Apis mellifera influence.③the driver of this effect is the competition between Apis melliferaand native bees for floral resources: Apis melliferatend to visit flowering plants with large nectar sources that make up a large proportion of the local community, and maintain a central role in the pollinator bee-plant pollination network, competitively replacing native pollinator bee access to floral resources, which ultimately resulted in a decrease in the local bee-plant interaction, resulting in a decrease in the complexity and stability of the bee-plant interaction network and the overall ecological structure.