Assessing the predation function via quantitative and qualitative interaction components

Abstract

Interactions among organisms can be defined by two main features: a quantitative component (i.e. frequency of occurrence) and a qualitative component (i.e. success of the interaction). Measuring properly these two components at the community level, can provide a good estimate of the ecosystem functions mediated by biotic interactions. Although this approach has been frequently applied to evaluate the eco-evolutionary consequences of mutualistic relationships, it has never been extended to the predation function and the associated pest control ecosystem service. Here, we introduce a simple measure that accounts for the quantitative and the qualitative components of predation interactions, and facilitates a precise characterization of this ecosystem function at the community level, while accounting for variations at species and individual levels. This measure arises as a fine indicator of predation pressure, and provides great opportunities to better understand how different components of predation and pest control potential vary across environmental gradients.