Vertical Zonal Distribution Patterns of Entomopathogenic Fungi in the Changbai Mountain

Entomopathogenic fungi (EPF) are critical drivers of ecosystem processes such as pest regulation and material cycling. However, their distribution patterns and the drivers influencing them along the elevational gradients remain unclear. This study investigated the diversity and distribution of EPF along a 300-2550 m altitudinal gradient on Changbai Mountain, focusing on their responses to vegetation belts and soil properties. A total of 21 genera and 35 EPF species were identified, with species diversity significantly declining with altitude (Shannon index, p < 0.05). High-altitude communities (1200-2550 m) showed similar structures across coniferous forests, Erman's birch forests, and alpine tundra, whereas low-altitude communities (300-1050 m) in broad-leaved and mixed forests were compositionally similar. Narrow-range species dominated, with many EPF being restricted to specific vegetation belts. Broad-leaved forests supported the highest EPF diversity, with families such as Cordycipitaceae showing strong preferences for these habitats. Soil properties (e.g., nitrogen, sulfur, phosphorus, moisture content, and pH) and shrub diversity were key drivers of EPF distribution. For instance, the abundance of Metarhizium, Cordyceps, Beauveria, and Polycephalomyces was positively correlated with nitrogen and phosphorus but negatively correlated with sulfur. Shrub diversity positively influenced EPF diversity in broad-leaved forests but negatively in coniferous forests. These findings highlight the interplay between altitude, vegetation, and soil conditions in shaping EPF communities, emphasizing the importance of preserving fungal diversity in alpine ecosystems to maintain ecological balance and support biological control strategies.