Studying individual variation in the role of plants within their populations

A niche approximation to frugivory network studies

In this work we study the variation in individual plants roles (interaction-wise) within their populations. We gathered data on the frugivory interactions of more than 1000 individual plants from 29 species to examine how mutualisms between species build up from interactions happening at the individual plant level.

At a network general level, the structure of individual-based frugivory networks was very similar to that of networks at the species level.

We then zoomed into each individual plant to characterise their interaction profile: how do individual plants differ in their interactions with frugivores? How specialised/generalised are individual plants compared to rest of the population? How similar are individual-based frugivory networks?

We built upon Young et al. 2021 Bayesian framework to infer pairwise interactions in individual-based networks accounting for sampling effort and the inherent stochasticity of field data. Using Bayesian posteriors of each pairwise interaction, analyses of individual specialisation based on niche theory showed that individual plants had, on average, quite generalised interaction profiles compared to the rest of the population. But there was large variation among regions and population. So, rather than each plant interacting with a distinct set of frugivores, most plants shared a similar set of frugivores in each population. In fact, in all populations, a few (1-3) frugivores contributed most of the interactions with individual plants

We also found similar individual interaction profiles across populations, regardless of bioregion or species. For example, in most populations there’s one or few ‘keystone’ plants that accumulate a high percentage of interactions, playing a central role.

Based on Paco Rodriguez Bluesky post

Common blackbird (Turdus merula) feeding on wild rose fruits (Rosa spp) in the north of the Iberian peninsula - Photo author: Jesús Lavedán