Frugivory and seed dispersal in a hyperdiverse plant clade and its role as a keystone resource for the Neotropical fauna

Abstract

Background and aims Much of our understanding of the ecology and evolution of seed dispersal in the Neotropics is founded on studies involving the animal-dispersed, hyper-diverse plant clade Miconia (Melastomataceae). Nonetheless, no formal attempt has been made to establish its relevance as a model system or indeed provide evidence of the role of frugivores as Miconia seed dispersers. Methods We built three Miconia databases (fruit phenology/diaspore traits, fruit–frugivore interactions, and effects on seed germination after gut passage) to determine how Miconia fruiting phenology and fruit traits for >350 species interact with and shape patterns of frugivore selection. In addition, we conducted a meta-analysis evaluating the effects of animal gut passage/seed handling on Miconia germination. Key Results Miconia produce numerous small berries that enclose numerous tiny seeds within water-sugar-rich pulps. In addition, coexisting species provide sequential, yearlong availability of fruits within communities, with many species producing fruits in periods of resource scarcity. From 2,396 pairwise interactions, we identified 646 animal frugivore species in five classes, 22 orders and 60 families, including birds, mammals, reptiles, fish and ants that consume Miconia fruits. Endozoochory is the main dispersal mechanism, but gut passage effects on germination were specific to animal clades; birds, monkeys and ants reduced seed germination percentages, while opossums increased it. Conclusions The sequential fruiting phenologies and wide taxonomic and functional diversity of animal vectors associated with Miconia fruits underscore the likely keystone role that this plant clade plays in the Neotropics. By producing fruits morphologically and chemically accessible to a variety of animals, Miconia species ensure short and long distance seed dispersal and constitute reliable resources that sustain entire frugivore assemblages.

The evolutionary ecology of bird–ant interactions: a pervasive but under-studied connection

“…The potential to interact commensally or compete with ants has a strong phylogenetic structure and was held by the ancestors of birds. The fact that several extant phylogenetic distant reptilian taxa had been reported to have commensal [ 71 ] and competitive [ 72 ] interactions with ants might suggest that even the reptilian ancestor of birds already had that proneness to interact with ants. However, although the birds ‘ancestor engaged in commensalism and competition with ants, many avian families currently do not, which suggests either that some bird families may have loss that capacity while radiating because selection led then to exploit niches where they do not coincide with ants, or that these families were less studied.…”

Cactus height increases the modularity of a plant–frugivore network in the Caatinga dry forest

“…Our findings imply that the vertical stratification of interactions is caused by differences in the locomotory and foraging behavior of different types of frugivores. While prior studies have shown how fruit nutritional (Pizo et al, 2021) or morphological traits such as seed size (Messeder et al, 2020) are important drivers of community‐wide interaction patterns, in Cactaceae it is also the distance of fruits to the ground that structure the use by different frugivore taxa. Our study reinforces the idea that cacti are keystone species in semiarid regions given their high fruit production and extended availability across both dry and wet seasons.…”

Phenological responses to climate change based on a hundred years of herbarium collections of tropical Melastomataceae

“…Moreover, entire communities could be reshaped following shifts in plant reproductive phenology, for example where coflowering patterns within the community are altered [55]. Particularly in the case of Miconia species, their fruits and seeds are usually dispersed by a bunch of frugivorous [56], and temporal alterations in the production of fruits and seeds may also impact animals that depend on it for food [50], likely leading to trophic mismatches and cascading effects on communities [46], in spite of possible network resilience by rewiring.…”