Ensemble Modeling Reveals Threats to Pollination Services From Asynchronous Range Shifts Between Camellia oleifera and Its Specialized Wild Bee Pollinators.

Camellia oleifera is a self-incompatible woody oil crop endemic to China that relies solely on insect pollination for seed production. Its flowering period, from late October to late December, coincides with seasonally low temperatures that suppress pollinator activity. Two oligolectic bee species, Colletes gigas and Andrena camellia, are Camellia oleifera's dominant and most efficient pollinators. This study employed ensemble species distribution models (SSDMs) to identify the potential distributions of C. oleifera and these two key pollinators under current and future climate scenarios. We integrated field survey data with open biodiversity database records to simulate suitable habitats and quantify their spatiotemporal overlap. Results indicate that: (1) The distribution of C. oleifera is primarily regulated by mean annual temperature, whereas precipitation of the driest quarter is the key constraint for both pollinator species. (2) Under current climatic conditions, a substantial overlap of 203.38 × 104 km2 was observed, accounting for 77.47% of the plant's suitable area and 95.47% of the pollinators' suitable area. (3) Under future scenarios, the total suitable area for both bee species is projected to increase by 21.82%, with the shared area expanding by 14.45% to 232.76 × 104 km2. (4) The geometric centroids of suitable habitats for all three species are projected to shift northwestward, indicating a general migration toward higher latitude. These findings enhance our understanding of plant-pollinator interaction under climate change and provide actionable insights for the spatial planning of C. oleifera cultivation and the conserving of its key wild pollinators.