Data from: Frugivore diversity increases evenness in the seed rain on deforested tropical landscapes

The diversity of tropical forests is strongly shaped by mutualistic
interactions involving plants and frugivores that disperse their seeds.
However, it is little known how decreases in the diversity of frugivores
can affect seed dispersal patterns, plant community composition and
species' coexistence in tropical forest landscapes. Here, we
investigated the effects of bird frugivore diversity on seed dispersal of
rare plant species and on the magnitude of equalizing effects on the seed
rain in open areas within 12 fragmented landscapes in the Brazilian
Atlantic Forest. We monitored the production of bird-dispersed seeds and
bird abundance in forest fragments, and sampled the seed rain and the
activity of birds attracted to experimental tree nuclei established in
neighboring pastures. The activity of frugivores in tree nuclei was
positively correlated with the diversity of birds recorded in nearby
forest fragments, and the seed rain diversity increased with frugivore
activity. The proportion of seeds dispersed more frequently than expected
by chance in tree nuclei increased linearly with the species'
richness of birds. The richness and abundance of active frugivores in
deforested areas promoted a seed rain with evenness and diversity up to
five times greater than the seed pool available in forest fragments due to
the proportional increase in the dispersal of rare plant species and a
concomitant proportional decrease in the dispersal of dominant fruiting
plants. Furthermore, every additional bird species detected in a site was
associated with a 10% increase in the equalizing effect on dispersed
seeds’ relative abundance. Our results show that the aggregated behavior
of avian frugivore communities on deforested areas results in higher
species richness in the seed rain of plant communities and underscore the
urgency to reduce bird species' loss and the simplification of their
communities in tropical landscapes.