<span class="word">Taxonomic <span class="word">Divergence <span class="word">and <span class="word">Functional <span class="word">Redundancy <span class="word">in <span class="word">Eucalyptus <span class="word">Rhizosphere <span class="word">Microbiomes <span class="word">Across <span class="word">Contrasting <span class="word">Brazilian <span class="word">Regions

Soil microbiomes play a central role in nutrient cycling and ecosystem stability in forestry ecosystems. We performed a high-resolution amplicon-based analysis of rhizosphere soils from eucalyptus plantations in two ecologically distinct Brazilian regions. Following ASV inference and phylogenetic reconstruction, we observed pronounced taxonomic divergence: Eldorado do Sul (ES) showed higher richness (1,221 vs. 755 ASVs) and phylogenetic diversity, whereas Três Lagoas (TL) exhibited greater evenness. Beta diversity revealed strong compositional dissimilarity (Jaccard = 0.915; Bray–Curtis = 0.843), largely driven by site-specific rare taxa, with only 8.1% of ASVs forming a shared core microbiome. Despite this turnover, PICRUSt2-based functional prediction indicated substantial conservation of dominant metabolic pathways. Core MetaCyc pathways were highly similar across sites and centered on central carbon metabolism, amino acid biosynthesis, and energy production, while weighted UniFrac distances were low (0.067), indicating phylogenetic similarity among abundant taxa. Region-specific metabolic enrichments were detected: ES showed greater predicted potential for chitin degradation, purine turnover, and nitrifier denitrification, whereas TL was enriched in alternative TCA variants, glyoxylate pathways, menaquinol biosynthesis, and aromatic compound degradation. These findings demonstrate the coexistence of pronounced taxonomic turnover with a relatively conserved predicted functional framework across contrasting eucalyptus systems.