Distinct temporal trajectories of bacterial and fungal networks during agricultural rewilding

Tropical land-use change from native forests to oil palm plantations has created widespread biodiversity loss, soil degradation, and disruption of microbial communities. As rewilding initiatives emerge to restore ecosystem function in post-agricultural landscapes, understanding microbial community assembly, diversity dynamics, and interaction networks is essential for informing effective restoration strategies. However, the pace and predictability of microbial reorganization following intensive monoculture remain poorly understood, particularly in tropical systems. We examined microbial reassembly across a five-year tropical rewilding chronosequence in a former oil palm plantation, using full-length 16S and ITS amplicon sequencing, ecological network modeling, and soil chemistry analyses. Bacterial and fungal alpha diversity increased over time, though with domain-specific trajectories. Generalized dissimilarity models revealed that soil phosphorus and carbon were dominant environmental filters shaping community turnover. Co-occurrence networks showed increasing complexity over time, with bacterial networks becoming progressively more interconnected, while fungal networks exhibited earlier but less sustained restructuring. These patterns suggest that microbial community coalescence during rewilding is asynchronous, structured, and shaped by deterministic environmental filtering and legacy effects of past land use. Our results provide evidence that tropical rewilding can rapidly reorganize soil microbial communities, enhancing diversity, connectivity, and compositional structure within just a few years. Full recovery is likely to require longer time frames, these early trajectories highlight the potential for rewilding to promote functional microbial reassembly in degraded tropical systems. By identifying taxonomic and network-based indicators of microbial reorganization, this study advances our understanding of community assembly theory and offers guidance for restoration practices in post-agricultural landscapes.