Modelling the fate of a plant-hummingbird interaction in the Campos Rupestres under climate change

Plant-pollinator interactions can shape species distributions and are vital for ecosystem functioning. However, their vulnerability to climate change remains poorly understood. In this study, we investigated the mutualistic relationship between the bromeliad Sincoraea albopicta and its hummingbird pollinator Augastes lumachella, both narrowly endemic in Campos Rupestres, Brazil. Using ecological niche modeling (ENM), we assessed the current and future distributions under climate change scenarios and compared the performance of climatic, topographic, and combined environmental datasets. Field observations confirmed that A. lumachella is the exclusive pollinator of S. albopicta. ENMs showed strong model performance for climatic and combined datasets, whereas topographic variables alone yielded unreliable predictions. Projections indicated severe range contractions for S. albopicta, with extinction predicted under high emission scenarios by 2100, whereas A. lumachella exhibited greater resilience. Only 16.9-21.9% of the hummingbird range overlapped with the bromeliad habitat, whereas almost 100% of the suitability areas of S. albopicta overlapped with A. lumachella, emphasizing asymmetric dependence. Currently, only 8-20% of suitable areas fall within protected zones, with anticipated future declines. We identified 1,638-3,551 km² priority conservation areas to safeguard this interaction. Our findings underscore the fragility of specialized plant-pollinator networks and the urgent need for conservation strategies that account for mutualistic dependencies in the face of climate change.