Authors: Stan Chabert, James H. Cane, Bernard E. Vaissière, Rachel E. Mallinger
Journal: Functional Ecology, 40, February 2026 (Commentary)
Abstract
It is widely documented that many crops depend on animal, primarily insect, pollination, but the degree to which pollinators limit yield in comparison with other factors is poorly understood. Recent studies conclude that pollinator visitation rates limit yields of many crops, based on positive correlations between these two variables. However, these studies typically suffer from incomplete data on two key variables that affect both pollinator recruitment and yield: flower density per area, and yield potential per flower, both driven by maternal resource availability.
The authors review the literature on animal-pollinated crops and show that yields can be positively associated with flower density, and that pollinator density can also be positively correlated with flower density. The third positive association often observed between pollinator density and yield may therefore result from these two underlying correlations, without a causal relationship. Likewise, the positive associations observed between maternal resources per flower and yield potential, and between maternal resources per flower and pollinator density per flower, can both explain the correlation between yield per flower and pollinator density per flower.
Using data reanalysed from the literature, the commentary shows that, without incorporating flower density and yield potential per flower, measuring yields and gradients of pollinator density per area alone can overestimate the degree to which pollinator visitation rates directly limit yield. This carries practical implications for assessing pollination deficits and designing pollinator-oriented interventions, a central question for HelEx and for future sunflower pollination research.
Open Access: Yes • Peer-reviewed: Yes • DOI: 10.1111/1365-2435.70269