Response of the invasive plant Ailanthus altissima (Mill.) Swingle and its two important natural enemies (Eucryptorrhynchus scrobiculatus (Motschulsky) and E. brandti (Harold)) to climate change

Abstract

• Predicted potential suitable areas for three species on CMIP6. • Distribution shifts of the three species were analyzed. • The most important climatic variables for each species were assessed. • The overlapping ecological niches of the three species were evaluated. Invasive species Tree-of-heaven ( Ailanthus altissima (Mill.) Swingle) caused serious damage on ecosystem, economy, and public health in the United States and Europe. Two weevils ( Eucryptorrhynchus scrobiculatus (Motschulsky) and E. brandti (Harold)) are considered to be potential enemies for biological control. In this study, we integrated potential distribution, bioclimatic suitability shifts and niche overlap to assess the global invasion risk of A. altissima under climate change and the possibility of E. scrobiculatus and E. brandti as potential natural enemies. Suitable area of A. altissima will be expanded under SSP 585. The future climate conditions do not seem to be suitable for the growth of E. scrobiculatus , but are conducive to E. brandti . We found that the suitable area of A. altissima would spread to the south and north, while two weevils spread mainly to the central and northern parts in the United States. The mean temperature of the coldest quarter (BIO11, 43.3%) was the most important bioclimatic variable in the forecasts for A. altissima and E. brandti . The wettest quarter’s mean temperature (BIO8, 35.7%) had the strongest influence on predictions for E. scrobiculatus . Our findings can provide a theoretical basis for preventing A. altissima from continuing to invade other areas. At the same time, it explained one reason why E. scrobiculatus and E. brandti could not effectively control A. altissima , and evaluated its feasibility as a potential natural enemy under future climatic conditions.