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

Background

Seed dispersal plays an important role in maintaining ecosystem biodiversity. Disperser species with many plant interactions tend to be more abundant while species with fewer interaction tend to be rarer. Fruit accessibility is one plant factor that limits frugivore visits. Plant height is thought to affect fruit accessibility.

Goals and Methods

The authors conduct a field study on Santo Antônio in Lajes municipality of northeastern Brazil. They monitor vertebrate frugivory events in cactus species for 11 months using wildlife cameras. The authors analyze cacti characteristics with the species and frequency of frugivore visits to determine how cacti height affects frugivory rates.

Conclusions and Takeaways

Cacti height has a significant impact on frugivory interactions within the Brazilian Caatinga. Ground dwelling frugivores favor shorter cacti while flying frugivores are able to access taller cacti. The authors conclude that cacti are keystone species in semiarid regions given their high rate of fruit production throughout wet and dry periods.