Bird-plant interaction networks in native forests and eucalyptus plantations within a protected area

Abstract

Frugivory is a plant-animal mutualistic interaction carried out mostly by birds. It consists in the bird consumption of fruits with later dispersion of the plants' seeds, helping in the vegetation regeneration. Frugivory can be affected by the habitat fragmentation and introduction of exotic species, which may alter the species interaction by extinction or competitor introduction. This study aimed to compare the structure of the network of frugivorous interactions between birds and plants in native forest and eucalyptus plantation. Birds were captured by mist nets and had their feces collected. Later, the seeds were identified in laboratory. The records of fruit consumption by birds in the zoochoric plant species present in the study area were also conducted. The data collected was used to build a network of interactions and identify the most important network metrics, species, and ecological functional groups in the studied environments. The results showed that the species composition, the connectivity of the relationships, the importance of the species for the interaction networks and the number of subgroups within the networks were highly similar between the native forest and the eucalyptus plantation. This could be explained by the favorable conditions that the studied eucalyptus plantations presented, such as the lack of anthropogenic activities, well-developed understory, and the presence of native surrounding vegetation, allowing practically the same seed dispersal capacity in both types of environments.