Potential distribution of the cashew tree (Anacardium occidentale) in the Caatinga under CMIP6 climate projections from EC-Earth3-Veg and MIROC6

Abstract

Introduction Cashew ( Anacardium occidentale ) is one of the most economically and socially important perennial crops in the Brazilian semiarid region, supporting rural livelihoods while also representing a native species adapted to tropical drylands. Understanding how climate change may alter the environmental suitability of native species is critical for conservation planning and sustainable land use in dryland ecosystems. Methods Here, we modeled the current and future potential distribution of Anacardium occidentale (cashew tree) across the Caatinga biome using MaxEnt (v.3.4.4) and bioclimatic predictors derived from two CMIP6 Earth System Models (EC-Earth3-Veg and MIROC6) under the SSP2-4.5 and SSP5-8.5 emission scenarios for the baseline period and future projections (2050 and 2070). Occurrence records were compiled from GBIF, SpeciesLink, and Embrapa databases and refined through ecological filtering and pedoclimatic zoning. Results The current model showed high predictive performance (AUC ≈ 0.88), with approximately 25% of the biome classified as highly suitable (≥ 0.5), mainly concentrated in the northern Caatinga. Suitability patterns were primarily driven by precipitation seasonality, annual rainfall, elevation (altitude), and vegetation cover, indicating strong dependence on water availability and habitat structure. Future projections revealed substantial contractions of suitable areas, particularly under SSP5-8.5, with losses ranging from 68% (EC-Earth3-Veg) to 76% (MIROC6). Both climate models consistently indicated that increasing temperatures and reduced seasonal precipitation will intensify aridification, leading to a spatial retreat of the species niche toward coastal and sub-humid zones—areas that correspond to the historical origin and current climatic refugia of the species. Discussion These results demonstrate the high vulnerability of Anacardium occidentale to ongoing climate change and highlight the importance of conserving coastal and sub-humid microrefugia, as well as implementing climate-adaptive management strategies to support rural livelihoods and extractive systems dependent on cashew production in the Brazilian semi-arid region.

The authors' abstract, as published at the source. Frontiers in Earth Science, 2026 · DOI ↗