Ashes in the air: the effects of volcanic ash emissions on plant–pollinator relationships and possible consequences for apiculture

Abstract

Pollinator foraging performance could be altered by volcanic ash contaminated flowers, pollen, and nectar. We used the honeybee (Apis mellifera) as a model organism to understand the effects that volcanic ash could have on apiculture and establish some of the mechanisms through which it could affect plant–pollinator interactions. Three mechanisms were investigated: (1) interference with resource location, (2) interference with resource consumption, and (3) disturbing digestive processes. Results indicate that plant–pollinator relationships could be altered by volcanic ash. On the one hand, honeybees seem to recognize flowers covered in ashes only after an adaptation period (i.e., learning). On the other hand, there is no avoidance mechanism to prevent ingestion of contaminated food that ultimately reduces survival. Apiculture could be negatively affected due to this natural disturbance and plant–pollinating relationships could be especially vulnerable to ash emissions due to the high exposure of pollen and nectar bearing structures susceptible to contamination. Additionally, nectar feeders gut morphology (i.e., convoluted, thin with no resistance to abrasion) enables ash particles in contaminated food to obstruct and lacerate the gut increasing mortality risk.