Data from: Are fragments fruitful? A comparison of plant–seed disperser communities between fragments and contiguous forest in north-east India

Plant–seed disperser interactions are critical for maintaining tropical
plant diversity. However, these interactions are altered by habitat
fragmentation, a pervasive threat to the tropics globally. We compared
vegetation structure, richness and composition of plant–seed disperser
interactions across two forest fragments (area: ~25 km2), and one
contiguous forest site in the last remaining lowland tropical forests in
north-east India. We compared network-level indices (nestedness,
generality, and vulnerability) and species-level indices (degree and
species strength) to identify key plant and bird groups across the three
sites. We found that the sites varied in habitat structure. The three
sites were more similar in the composition of avian seed dispersers than
plants. The low similarity in plant-seed disperser interactions between
the three sites was likely influenced by low similarity in fruiting
plants. The fragmented sites exhibited fewer pairwise interactions and
were characterized by a higher representation of small-seeded plant
species, climbers, and open-forest birds. Small-bodied birds (bulbuls and
barbets) played a central role in all the seed dispersal networks, while
large-bodied birds (hornbills) performed persistent interactions with
large-seeded plants at all sites. This is one of the first studies from
the Asian tropics to investigate the differences in the plant–avian seed
disperser communities between forest fragments and contiguous forest. Our
findings highlight the conservation value of fragments given their
potential to hold a distinct set of plant–seed disperser interactions
thereby maintaining functional diversity in tropical fragmented
landscapes.