Integrating biogeographic approach into classical biological control: Assessing the climate matching and ecological niche overlap of two natural enemies against common ragweed in China

Plant invasion is considered a high priority threat to biodiversity, ecosystems, the environment, and human health worldwide. Classical biological control (biocontrol) is a generally safer and more environmentally benign measure than chemical controls in managing invasive alien plants (IAPs). However, the impacts of climate change and the importance of climate matching in ensuring the efficiency of biocontrol candidates in controlling IAPs are likely to be underestimated. Here, based on the ensemble model and n-dimensional hypervolumes concepts, we estimated the overlapping areas between Ambrosia artemisiifolia and its two most effective natural enemies (Ophraella communa and Epiblema strenuana) under climate change in China. Moreover, we compared their ecological niches, further assessing the impact of climate change on the efficiency of two natural enemies in controlling A. artemisiifolia in China. We found that the potentially suitable areas of the two natural enemies and A. artemisiifolia were primarily influenced by temperature and human influence index variables. Under near current climate, the overlapping area between O. communa and A. artemisiifolia was the largest, followed by E. strenuana and A. artemisiifolia, and both two natural enemies and A. artemisiifolia. The ecological niche between A. artemisiifolia and O. communa was most similar (0.64), followed by A. artemisiifolia and E. strenuana (0.55). The separate control (the niche separation areas of the two natural enemies against A. artemisiifolia) and joint-control (the niche overlap areas of the two natural enemies against A. artemisiifolia) efficiencies of the two natural enemies against A. artemisiifolia will both increase in future climates (the 2030s and 2050s) in northern and northeastern China. Our findings demonstrate a new approach to assess control efficiency and screen potential release areas of two natural enemies against A. artemisiifolia in China without the need for actual field release or experimentation. Moreover, our findings provide important clues for ensuring the classical biocontrol of IAPs worldwide.

Automated summary

Plant invasion poses a significant threat to biodiversity, ecosystems, the environment, and human health. Classical biological control is a safer and more environmentally friendly method than chemical controls for managing invasive alien plants. However, the impact of climate change and the importance of climate matching in biocontrol efficiency are often underestimated. This study explores the overlapping areas and ecological niches between Ambrosia artemisiifolia (a common invasive plant) and its two natural enemies under climate change in China. The study reveals that temperature and human influence variables significantly influence the potential habitats of the natural enemies and the invasive plant. Moreover, the control efficiency of the natural enemies against A. artemisiifolia is expected to increase in future climates. The findings provide a new approach for evaluating control efficiency and identifying potential release areas for natural enemies without the need for field release or experimentation. Furthermore, the study has important implications for the classical biocontrol of invasive alien plants worldwide.