Response of honeybee colony size to flower strips in agricultural landscapes depends on areal proportion, spatial distribution and plant composition

We investigated the effects of the areal proportion, spatial distribution and plant composition (quality) of flower strips in agricultural landscapes on the size of honeybee colonies using individual-based models (BEESCOUT, BEEHAVE). For this purpose, we developed 25 landscape scenarios for an intensively used landscape (3 × 3 km) in Havelland (Brandenburg, Germany). In the scenarios, we varied areal proportion (0.22–1.04%), distribution (clustered vs. even) and quality (high vs. low pollen and nectar supply) of flower strips. Then, we simulated the response of honeybee colony size to the landscape scenarios over twelve years with 100 repetitions per scenario. Colony size increased with increasing areal proportion and more even distribution of flower strips. However, this was only true for flower strips of high quality, whereas low-quality flower strips did not benefit the honeybee colonies. Our approach can help to pinpoint optimal quality, areal proportion and distribution of additional food sources for honeybees provided by flower strips in agricultural landscapes.