Evidence item

Bacterial temporal turnover was significantly greater in forest gaps than in closed-canopy soils and was accompanied by greater seasonal divergence in community composition. Null-model analyses showed an increase in the relative contribution of deterministic processes to the assembly of both bacterial and fungal communities within gaps. Although niche breadth expanded in both kingdoms, niche organization diverged: fungal communities showed greater niche overlap and a higher proportion of generalists, whereas bacterial communities showed reduced niche overlap. Co-occurrence networks in gap soils were more densely connected but contained fewer keystone taxa and showed a topologically simplified architecture. Correspondingly, predicted functional potential was associated primarily with keystone-taxon structure in closed-canopy soils but with both keystone-taxon and whole-community structure in gap soils.