Climate change reduces pollination services and sunflower yields across Europe and Northern Africa

Abstract

Sunflower (Helianthus annuus) productivity is highly dependent on pollinators, yet the effects of climate on pollination services and crop yield remain poorly understood. In this study, we investigate how temperature gradients influence flower-visiting communities, pollination services, and sunflower productivity across Europe and Northern Africa. We conducted standardized two-year (2022 and 2023) pollination exclusion experiments across 36 sunflower fields spanning a broad climatic gradient, from temperate regions in Slovenia to arid conditions in Algeria. We found that sunflower production (seed set, seed number, and oil content) relied heavily on insect pollination. However, this benefit declined with rising temperatures, likely due to the observed decreases in wild pollinator diversity at high temperatures. Integrating these results with climate change projections suggests that southern Europe and northern Africa may soon face severe losses of pollination-mediated sunflower yield. Climate-driven reductions in pollination services pose a major risk to sunflower production in warm regions. These findings highlight the urgent need for pollinator conservation measures and the promotion of climate-resilient agricultural strategies to safeguard pollination services and ensure sustainable sunflower production under a warming climate.