Anthropogenic disturbances simplify frugivory interactions in Amazonia

Frugivory interactions are essential ecological processes for the
regeneration of tropical forests, ensuring ecosystem resilience following
disturbances. However, little is known about how frugivory interactions
are shaped by anthropogenic disturbances, especially in Amazonia – one of
the most biodiverse ecosystems on Earth. We investigate how selective
logging and forest fires impact both arboreal and terrestrial frugivory
interactions in Amazonian forests. We focus on four forest classes:
Undisturbed, Logged, Logged-and-17y-burned (burned 17 years before
sampling) and Logged-and-3y-burned (burned three years before sampling).
We recorded 4670 frugivory interactions at the community level, in a
sampling effort of 31 484 h. Undisturbed forests sustained a significantly
higher number of species and interactions when compared to
Logged-and-17y-burned forests. Selective logging and forest fires did not
alter significantly the structural properties of the frugivory networks,
which were highly modular, moderately specialised, poorly connected and
non-nested. Regarding community composition, we detected high β-diversity
of plant species, frugivore species, and their interactions between all
study areas, as well as within and between forest classes, mainly driven
by spatial turnover. Logged-and-17y-burned forests hosted the most unique
interaction composition compared to Undisturbed forests. Our study
provides novel evidence that anthropogenic disturbances, particularly
selective logging and forest fires, negatively affect frugivory
interactions in Amazonian forests. These effects may persist for years
after the initial disturbance events and could be exacerbated due to the
predicted increase in forest fires driven by climate change.