Analysis of a hyper-diverse seed dispersal network: modularity and underlying mechanisms

Abstract

Mutualistic interactions involving pollination and ant-plant mutualistic networks typically feature tightly linked species grouped in modules. However, such modularity is infrequent in seed dispersal networks, presumably because research on those networks predominantly includes a single taxonomic animal group (e.g. birds). Herein, for the first time, we examine the pattern of interaction in a network that includes multiple taxonomic groups of seed dispersers, and the mechanisms underlying modularity. We found that the network was nested and modular, with five distinguishable modules. Our examination of the mechanisms underlying such modularity showed that plant and animal trait values were associated with specific modules but phylogenetic effect was limited. Thus, the pattern of interaction in this network is only partially explained by shared evolutionary history. We conclude that the observed modularity emerged by a combination of phylogenetic history and trait convergence of phylogenetically unrelated species, shaped by interactions with particular types of dispersal agents.

Inferring species roles in metacommunity structure from species co-occurrence networks

“…The structure of the co-occurrence network herein analysed, suggests a distribution of roles where only a few species are responsible for the metacommunity level connectivity. This pattern of role distribution [39] has also been described in a wide variety of biological networks including spatial [36,54], mutualistic [33,40,55], food web [35], genetic [34] and metabolic ones [39], supporting the commonality of this network structure. However, few studies have underscored the importance of biological attributes as determinants of species roles (but see [35,55]).…”

Biodiversity, Species Interactions and Ecological Networks in a Fragmented World

“…Memmott, 1999) and plant-frugivore/seed disperser networks (e.g. Donatti et al, 2011;Schleuning et al, 2011a), with less familiar forms including plant-ant networks and host-symbiont interactions (e.g. gut microbiomes; Purdy et al, 2010).…”

Sampling completeness in seed dispersal networks: When enough is enough

“…Heleno, Olesen, Nogales, Vargas, & Traveset 2013;Carlo & Yang 2011;Donatti et al 2011;Mello et al 2011). The dispersal of seeds away from the mother plant is a key process, allowing plants to avoid competition, find suitable conditions for germination, and expand their distribution range (Traveset, Heleno, & Nogales 2014).…”