Seed dispersal and seed predation networks highlight important dual roles for plants and terrestrial vertebrates in a tropical forest

The dispersal and predation of seeds by animals are important, and inextricably linked, drivers of plant species diversity and ecosystem stability. Within tropical forests, these interactions involve diverse vertebrate communities with the same species often contributing to both processes. Yet, multi‐level interactions are rarely examined at community‐scales, limiting our ability to identify the most important species driving plant recruitment – a crucial aspect of demographic dynamics. Here, we build a multi‐layered network of vertebrate seed dispersal and seed predation interactions from a tropical forest in Thailand, to identify important interactors and assess the plant and animal traits that influence species' roles. The dataset encompassed interactions between 36 plant and 25 ground‐foraging vertebrate species observed in camera‐traps ( > 1000 camera‐trap days). Over half the plant and animal species were involved in both dispersal and predation, with the dispersal network involving more species than the predation network. Four of six animal species that were major interactors had dual roles and two were seed predators, indicating that analyses of networks in isolation would incompletely reflect their importance in plant recruitment. Abundance was positively associated with species' roles (degree, species strength) for plants and animals in the seed dispersal network but not the predation network; none of the size traits (fruit/seed size; body mass) nor seed hardness were related to species' roles. Plant multi‐layer versatility, a measure of relative importance within and between interaction types, was not correlated with any measured traits, suggesting that more complex trait associations define versatility. In conclusion, the most important species for influencing patterns of plant recruitment are more accurately identified by measuring roles across multiple levels, because of the dual involvement of plant and animal species in both seed dispersal and predation. However, a broader range of traits that might determine these roles needs to be studied.