Abstract
<title>Abstract</title> <p> Climate change may reshape biodiversity vulnerability in regions already affected by severe environmental degradation, yet the spatial overlap between future climatically suitable areas and post‑disaster landscapes remains poorly understood. In the Rio Doce watershed, southeastern Brazil, the Samarco dam collapse released mining tailings across riparian ecosystems, altering vegetation, soils, and environmental quality in areas important for pollinator conservation. Here, we modeled climate suitable area for 48 native bee species and assessed changes in predicted richness, community composition, species‑level responses, and overlap with the tailings‑affected zone under baseline and future climate scenarios. Predicted richness remained concentrated in the western, southwestern, and far eastern portions of the watershed, whereas northern and central sectors showed greater reductions under the high‑emission scenario. Temporal changes in community composition were driven primarily by richness differences rather than species replacement, indicating that future communities may become impoverished subsets of current ones. Species responses were highly asymmetric, with contractions exceeding expansions: <italic>Euglossa crassipunctata</italic> is projected to lose about 82% of its suitable area, while <italic>Melipona bicolor</italic> and <italic>Euglossa analis</italic> may lose over half. Overlap with the tailings‑affected zone remained low for most species but increased for climatically vulnerable ones. Notably, 22% of the remaining suitable area for <italic>E. crassipunctata</italic> under the high‑emission scenario overlapped with the tailings footprint. These findings suggest that climate change selectively reduces suitability for native bees in a watershed threatened by post‑disaster degradation and provide a spatial framework to support monitoring, restoration, and pollinator conservation under interacting environmental pressures. </p>