Species Distribution Modeling Reveals Future Climate Refugia and Important Areas for Rocky Plants in Brazil's Iron...

Climate change is expected to substantially alter the distribution of rupestrian plant species in the Iron Quadrangle (IQ), southeastern Brazil, with important implications for conservation planning. In this study, we assessed how future climate scenarios may affect the distribution of eight rupestrian angiosperms, Aiouea tetragona (Lauraceae), Dyckia consimilis, D. rariflora, Hoplocryptanthus ferrarius, H. schwackeanus, Paepalanthus amoenus, P. magalhaesii (Eriocaulaceae), and Vriesea minarum (Bromeliaceae), and identified priority areas for conservation. Occurrence records were compiled from online herbaria and datasets provided by Vale S.A., followed by spatial thinning to reduce sampling bias. Ensemble ecological niche models were fitted using ENMTML based on current climatic suitability derived from WorldClim v2.1 bioclimatic variables. Future projections incorporated three CMIP6 general circulation models under SSP1-2.6 and SSP5-8.5 scenarios for 2050 and 2090. We further quantified the overlap between climatically suitable areas and protected areas, identifying candidate climatic refugia and potential ecological corridors. All species achieved acceptable to excellent predictive performance (AUC > 0.75; TSS > 0.5). Projections indicated widespread contractions in climatically suitable areas, particularly for xeromorphic taxa such as A. tetragona, D. rariflora, H. ferrarius, and P. magalhaesii, which approached near-zero suitability by 2090 under SSP5-8.5. In contrast, D. consimilis and H. schwackeanus showed comparatively stable suitability patterns, while P. amoenus and V. minarum exhibited transient gains under intermediate scenarios. Persistent suitability hotspots were concentrated along the Gandarela-Caraça axis, including areas such as Serra do Gandarela and the RPPN Horto Alegria, indicating climatically stable zones that may function as future refugia for edaphically specialized rocky-field species. Our results indicate that climate mitigation alone will likely be insufficient to safeguard rupestrian flora in the Iron Quadrangle. Proactive conservation strategies will be necessary, including strengthening ecological connectivity, establishing seed banks and germplasm collections, and planning assisted translocations. Additionally, we provide an interactive tool designed to translate model outputs into management-oriented products that can support decision-making and prioritize conservation interventions in key landscapes such as the Gandarela-Caraça corridor.