Accelerating global change and biodiversity loss threaten crop pollination, a key ecosystem service vital for food security and largely dependent on wild pollinators. Increasing climatic variability may reduce pollination stability, but diverse pollinator communities with complementary thermal niches could buffer these effects. This SHOWCASE study, authored by partners Agroscope and ETH Zurich, examines whether agri-environmental schemes (AES) meadows around sweet cherry orchards enhance wild bee diversity, climatic response diversity and pollination resilience, with particular attention to the role of cold-tolerant species such as bumblebees.
Sweet cherry orchards in the Swiss northern plateau were used to study how extensively managed AES meadows influence wild bee communities, their thermal niches and pollination services. Bees visiting cherry flowers were sampled during bloom in 15 orchards, fruit set was measured as an indicator of pollination, and thermal niches were calculated using temperature data, complemented by bee observations from apple orchards in the same region. Statistical models were then used to assess how the proportion of AES meadows relates to wild bee diversity and abundance, thermal niche complementarity and breadth, thermal resilience and fruit set, while comparing the roles of wild and managed pollinators.
Results showed that cherry orchards surrounded by higher amounts of extensively managed AES meadows had wild bee communities with greater thermal complementarity and thermal resilience, largely driven by higher overall bee diversity and the presence of bumblebees with broad, cool-temperature niches, while managed bees did not significantly enhance resilience. Wild pollinators were particularly important for sustaining flower visitation under variable and cool conditions, highlighting the role of AES measures in supporting resilient pollination services under climate variability. However, no effects of enhanced thermal community niches on cherry yield were detected, likely because exceptionally unfavourable weather conditions during the study year masked pollination effects.
Read the full study here.