Ecosystems

As a keystone clade, Miconia species support a huge variety of frugivores

Different species fruit sequentially, offering a year-round food resource.

The large and highly diverse Miconia clade has been key to our understanding of the ecology of frugivory and seed dispersal in the Neotropics. Miconia comprises over 1000 species that span the entirety of the Neotropic range and produce berries in a variety of shapes, sizes, and colours. The clade is considered a keystone plant resource (KPR) because its fruits are consumed by a wide variety of fauna, giving it a disproportionally large role in supporting frugivore communities. However, there has been no work done formally quantifying Miconia’s importance as a frugivore resource and systematically detailing its interactions with those species.

Some Miconia berries. Source: Messeder et al. 2020.

In a new article published in Annals of Botany, lead author João Vitor S. Messeder and colleagues evaluated more than 350 species of Miconia, noting fruit traits and phenology, as well as relationships with frugivores. The group also looked at the effect on seed germination of passing through the guts of or being handled by various animals.

The researchers found that Miconia provided food for 646 animal species across 60 different families, including birds, mammals, reptiles, fish, and ants, supporting their role as KPRs. Birds consumed the fruits in more than 70% of observations, with more than 460 bird species recorded. Part of the clade’s value to frugivore communities comes from the fact that multiple Miconia species living in the same community fruit sequentially – some through periods when food is otherwise scarce – providing a year-round food source for the animals.

“Our investigation shows that Miconia species commonly produce fruits during the dry season in several seasonal habitats, making them a reliable food source during periods of food scarcity,” write the authors. “Year-round fruit availability at the community-level entails a higher probability of interaction, for both resident and migratory species, and ensures seed dispersal services and helps to maintain biodiversity.”

The various types of animals consuming Miconia seeds had differing effects on seed viability after passing through their guts. Consumption by birds and monkeys, as well as handling by ants, reduced seed germination (relative to hand extraction of seeds by researchers), while being eaten by opossums increased it. Regardless, any consumption was better than not being eaten, since germination is light-dependent and does not occur unless seeds are removed from the fruit, a service frugivores offer the plants. Being consumed by a variety of animals provided Miconia with both short and long distance seed dispersal.

“[T]he recognition of Miconia as a keystone plant taxon for Neotropical frugivores is the first step towards applying this knowledge to better conservation and management practices,” write the authors.

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