About the talk

Facilitation, an interaction where one species benefits another, is recognized as a key process supporting local species persistence. However, the tendency of beneficiary species to compete with their benefactors as they mature has reinforced the notion that facilitation plays a minor role in long-term community structuring compared to competition. We argue that facilitation can consistently enhance diversity when it occurs reciprocally between interacting species. Drawing from a global dataset of 96 plant-community recruitment networks, encompassing 2403 non-transient populations across 23 countries, we observed that c. 90% facilitation events were reciprocated, primarily mediated by intermediary species that transmit benefits through indirect facilitation loops, ultimately returning these benefits to the original benefactors. Our analyses revealed stronger positive effects within longer facilitation loops coupled with fewer negative interactions within the loops, which are essential conditions for benefactors to receive increased returns and, consequently, for the long-term persistence of indirect reciprocal facilitations. These two conditions also synergistically foster species coexistence, leading to a positive empirical relationship between indirect reciprocity and species richness that is substantiated by numerical simulations. Our findings underscore the pivotal role of indirect reciprocal facilitation in maintaining biodiversity, challenging the prevailing notion of competition as the dominant force governing species coexistence.

About the speaker

My scientific career revolves around three research lines pertaining to (1) the ecological and evolutionary mechanisms that jointly shape species assemblages at the community and macroecological scales, (2) the development, improvement, and assessment of phylogenetic methods, and (3) the links between biodiversity and human well-being. While these lines represent clearly differentiated research interests, phylogenetics is a cross-cutting background for all of them. Considering that plants are my true passion in science, my profile is defined as a Phylogenetic Plant Ecologist.