Identifying Drivers Affecting the Spatial Distribution of Suitable Habitat for the Pine Wood Nematode (Bursaphelenchus xylophilus) in China: Insights From Ensemble Model and Geographical Detector

Biological invasions have become an important threat to global ecological security and forest health, and exploring the environmental driving mechanisms of invasive species is important for prevention and control. Bursaphelenchus xylophilus (Steiner and Buhrer, 1934), as a highly destructive invasive species, has its distribution and spread driven by a combination of various environmental factors. The study systematically evaluated the habitat suitability and key driving factors of B. xylophilus in the current period by applying an ensemble model and an optimized parameter-based geographical detector. The results indicate that bioclimatic, vegetation indices, topographical features, and human activities are key environmental factors influencing the distribution of B. xylophilus, with highly suitable areas primarily located in southern, northern, and northeastern China. Meanwhile, the synergistic interaction between slope and population density (PD) significantly enhanced the suitability of B. xylophilus distribution, while the interaction between normalized difference vegetation index (NDVI) and global human influence index (GHII) exhibited a nonlinear weakening effect. Additionally, the habitat suitability of B. xylophilus increased with the expansion of isothermality, mean temperature of the wettest quarter, precipitation of the driest month, global human footprint, GHII, and PD, while it gradually decreased with the increase of UV-B seasonality and NDVI. This study thoroughly explored the mechanisms by which various environmental factors influence the habitat suitability of B. xylophilus, revealing the complexity of regional driving factors. The findings not only provide theoretical support for predicting the ecological suitability of B. xylophilus but also offer scientific evidence for comprehensively analyzing the key factors affecting its distribution.