Concepts of pollinator performance: is a simple approach necessary to achieve a standardized terminology?

Abstract

Quantifying the importance of pollinators for reproductive success of plants is a central question in reproductive biology. However, the literature contains a profusion of terms and sometimes conflicting definitions. This inconsistency is a barrier to broad comparisons and conceptual advances in different fields. In recent decades, some widely disseminated studies have proposed recommendations to foster greater standardization. Nevertheless, the literature continues with little uniformity, and terms such as “efficacy,” “efficiency,” and “effectiveness” of pollinators are still used inconsistently. Previous studies concerning conceptual and terminological uniformity provided a series of particular terms related to specific metrics and/or strict definitions for these widely used terms. I here propose comprehensive verbal definitions for the terms that have historically been used by most specialists. Pollinator performance in achieving reproductive success is defined here as its effectiveness, which is, broadly, given by the product of two components: pollinator efficacy and intensity of visitation. In some approaches, a third component – pollinator efficiency – is important for estimates of its effectiveness. The definitions suggested here apply to different variables, parameters, and procedures for study, and may refer to either individuals or populations of a pollinator species, or to functional groups of pollinators. This terminology can be applied widely, as it is not constrained by the scope, approach or scale of a study. A basic terminology with simple definitions may facilitate consistent use of these terms by specialists, particularly among younger investigators, thus surmounting the first barrier to future proposals for conceptual and methodological unification at larger scales.