Impact of climate change on the potential distribution of Macaúba (Acrocomia aculeata, Acrocomia totai, Acrocomia intumescens) in Brazil

Understanding how climate change may alter species distributions is important for conservation planning and for the sustainable expansion of bioenergy crops. Macaúba palms (Acrocomia aculeata, A. totai, and A. intumescens) represent promising non-edible oilseed resources in Brazil, yet their future environmental suitability remains insufficiently quantified. Here, we developed a standardized ensemble modelling framework that integrates biologically informed calibration areas, spatial block cross-validation, and multi-stage covariate selection to evaluate climate-driven shifts in the potential distribution of the three species. A key methodological feature of this study is the generation of bioclimatic layers aligned with temporally explicit 20-year historical windows that match occurrence records, reducing temporal mismatch between climate and biodiversity data. Models were built using climatic, edaphic, and elevation predictors, and future projections incorporated six CMIP6 global models under three SSPs (SSP2-4.5, SSP3-7.0, SSP5-8.5) for mid- and late-century scenarios. All species achieved high predictive performance but differed sharply in their environmental responses. Acrocomia aculeata exhibited broad climatic and edaphic tolerance, resulting in moderate range contractions. Acrocomia totai showed greater sensitivity to water deficit and soil structure, yielding intermediate projected losses. Acrocomia intumescens, with narrow climatic–edaphic requirements, emerged as the most vulnerable, with declines exceeding 50% under high-emission scenarios. Together, these findings reveal a gradient of ecological breadth within Acrocomia, ranging from generalist to specialist species, with direct implications for conservation, agricultural zoning, and climate adaptation strategies. The results demonstrate the value of synchronizing historical climate windows with occurrence dates to sharpen the detection of climate-driven range shifts and enhance the temporal coherence of species distribution models. Although climate change is likely to affect bioenergy crops to some extent, our results show that its effects on A. aculeata are comparatively limited. This supports its role as one of the most promising species for bioenergy production in Brazil.