Soil fungal and bacterial ITS sequence on La Réunion Island
Non-native plant invasion have become a major problem worldwide, however, its impact on soil microbial communities and how changes in plant community functional traits under invasion influence microbial composition remain understudied. In addition, the response of soil microbial communities to non-native plant invasion during vegetation succession is also unknown. To address these gaps, we collected soil samples and recorded plant functional trait and species abundance along plant invasion gradients in lava flow vegetation and lowland rainforest (representing early and late successional stages) on La Réunion Island. We evaluated functional trait variation in plant communities under invasion by using the community weighted mean (CWM) of functional traits and trait differences between non-native and native plants within plant community. Our results showed that higher non-native plant abundance had lower soil fungal network complexity and stronger correlation between plant and bacterial communities, but it had no effect on soil fungal and bacterial diversity or abundance, regardless of successional stage. While the interaction between non-native plant abundance and successional stage shifted bacterial community composition, fungal community composition was shifted by successional stage alone. Trait differences between non-native and native plants and the CWM of plant functional traits were identified as key variables explaining soil fungal and bacterial community composition, under plant invasion, respectively. Our study demonstrates that non-native plant invasion, characterized by non-native plant abundance, had limited influence on soil microbial communities. Instead, the functional trait of plant community and trait differences between native and non-native plants could be better variables for capturing shift in soil microbial community composition.