Abstract:

Background & Aim: In recent years, the global rise in demand for pollination services of insect-pollinated crops has led to a surge in the use of managed alien pollinators. This extensive proliferation significantly impacts mutualistic relationship between native plants and pollinators, posing serious threats to local biodiversity and ecosystem stability.

Progresses: This article reviews the impacts of alien pollinators on native plants, native pollinators and pollination networks. (1) Morphological and behavioral differences between alien and native pollinators often render the former inefficient or ineffective pollinators for native plants, negatively affecting plant reproductive success. However, in pollination-limited environments, alien pollinators may supplement pollination effectively. The specific flower-visiting preferences of alien pollinators and their impact on the flower-visiting behavior of native pollinators alter pollen flow, gene flow, and consequently, the genetic structure of plant populations. In addition, alien pollinators also exert new selective pressures on floral traits, driving adaptive evolution in plant populations. (2) Alien pollinators may outcompete or prey on native pollinators, disrupt their reproductive process, or spread of pathogens, thereby threatening the diversity and abundance of native pollinators species. (3) As generalist species, alien pollinators integrate rapidly into the pollination networks, forming numerous new connections with native plants. This often increases the generalization and nestedness of the entire pollination network, profoundly affecting its stability.

Prospects: In China, research on alien pollinators has mainly focused on their agricultural pollinations. In the future, we should: (1) Investigate the mechanisms trough which alien pollinators impact native flowering plants, pollinators, and the structure and function of pollination network. (2) Expand research level across species, communities and ecosystems. (3) Broaden the geographical and temporal scales of research, incorporating advanced technologies and methodologies, while accounting for global warming and agricultural intensification.

Suggestions: Given the continuous expansion of alien pollinator distribution in China, measures are urgently needed to protect native plant and pollinator diversity, and to maintain ecosystem authenticity and stability. (1) Strategic planning is necessary for the introduction and management of alien pollinators. (2) Establish native pollinator nature reserves, with priority species and conservation area. (3) Additionally, the promotion and conservation of native pollinators are essential to provide sustainable pollination services for crops, and to avoid ecological damage caused by the introduction of alien pollinators.

Key words: alien pollinators, native plants, native pollinators, pollination network