Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1002/eap.2216
Licence creative commons licence
Title (Primary) Honey bee colony performance affected by crop diversity and farmland structure: a modeling framework
Author Horn, J.; Becher, M.A.; Johst, K.; Kennedy, P.J.; Osborne, J.L.; Radchuk, V.; Grimm, V.
Journal Ecological Applications
Year 2021
Department OESA
Volume 31
Issue 1
Page From e02216
Language englisch
Topic T5 Future Landscapes
Keywords Apis mellifera, colony viability, cropping system, decline, forage availability, forage gaps, honey bees, modeling, BEEHAVE, landscape generator, crop diversity
Abstract Forage availability has been suggested as one driver of the observed decline in honey bees. However, little is known about the effects of its spatiotemporal variation on colony success. We present a modeling framework for assessing honey bee colony viability in cropping systems. Based on two real farmland structures, we developed a landscape generator to design cropping systems varying in crop species identity, diversity, and relative abundance. The landscape scenarios generated were evaluated using the existing honey bee colony model BEEHAVE, which links foraging to in‐hive dynamics. We thereby explored how different cropping systems determine spatiotemporal forage availability and, in turn, honey bee colony viability (e.g., time to extinction, TTE) and resilience (indicated by, e.g. brood mortality). To assess overall colony viability, we developed metrics, PH and PP, which quantified how much nectar and pollen provided by a cropping system per year was converted into a colony’s adult worker population. Both crop species identity and diversity determined the temporal continuity in nectar and pollen supply and thus colony viability. Overall farmland structure and relative crop abundance were less important, but details mattered. For monocultures and for four‐crop species systems composed of cereals, oilseed rape, maize and sunflower, PH and PP were below the viability threshold. Such cropping systems showed frequent, badly timed, and prolonged forage gaps leading to detrimental cascading effects on life stages and in‐hive work force, which critically reduced colony resilience. Four‐crop systems composed of rye‐grass‐dandelion pasture, trefoil‐grass pasture, sunflower and phacelia ensured continuous nectar and pollen supply resulting in TTE > 5 years, and PH (269.5 kg) and PP (108 kg) being above viability thresholds for five years. Overall, trefoil‐grass pasture, oilseed rape, buckwheat and phacelia improved the temporal continuity in forage supply and colony’s viability. Our results are hypothetical as they are obtained from simplified landscape settings, but they nevertheless match empirical observations, in particular the viability threshold. Our framework can be used to assess the effects of cropping systems on honey bee viability and to develop land‐use strategies that help maintain pollination services by avoiding prolonged and badly timed forage gaps.
Persistent UFZ Identifier
Horn, J., Becher, M.A., Johst, K., Kennedy, P.J., Osborne, J.L., Radchuk, V., Grimm, V. (2021):
Honey bee colony performance affected by crop diversity and farmland structure: a modeling framework
Ecol. Appl. 31 (1), e02216