Matchmaking: a meta‐analysis of plant growth‐promoting microbial partnerships driving tree seedling performance in the Atlantic Forest biome

Abstract Introduction The Brazilian Atlantic Forest (BAF) is a biodiversity hotspot, and inoculating native seedlings with plant growth‐promoting microorganisms (PGPMs) may enhance seedling vigor for forest restoration. Objectives We performed a meta‐analysis to evaluate the effects of PGPMs on BAF seedlings and identify strategies to optimize restoration outcomes. Methods We synthesized data from 60 studies reporting biomass and nutrient content in seedlings inoculated with arbuscular mycorrhizal fungi (AMF), plant growth‐promoting bacteria (PGPB), nitrogen‐fixing bacteria (NFB), or AMF + NFB. Responses were compared across successional stages (pioneer, early, late secondary), functional groups (N 2 ‐fixing vs. non‐N 2 ‐fixing), and experimental conditions (fertilization, inoculum complexity, and substrate sterility). Results AMF inoculation produced the strongest benefits, particularly for pioneer and early secondary species. Pioneers also showed enhanced growth and N content with NFB, while both AMF and PGPB increased P content. Overall, PGPM inoculation was most effective in non‐N‐fixing species and early successional species, using single strains under sterile conditions, combined with P fertilization. Conclusions Matching PGPM inoculants with the successional stage of target species can improve nursery practices and enhance restoration success.