Researchers from Azorean Biodiversity Group published a scientific paper in the highly recognized Journal PNAS

Investigators of the Azorean Biodiversity Group (CITA-A) published a scientific paper on the prestigious  Journal, PNAS - Proceedings of the National Academy of Sciences of the United States.

Robert Whittaker from the University of Oxford, integrated researchers  from Azorean Biodiversity Group (François Rigal, Paulo A. V. Borges, Sofia Terzopoulou, Pedro Cardoso, Kostas Triantis) and our collaborator  François Guilhaumon, analyzed functional trait data for spiders and beetles on the Azores to quantify the impact of exotic species on island diversity.

This study is novel because most island biogeography studies have focused on calculations of species richness and diversity, yet few have examined the diversity of species’ functional traits.

In this publication authors show that "Species trait diversity increases with island size in the Azores"

In this study of spiders and beetles in the Azores researchers  found that the diversity of the species’ functional traits – characteristics that determine how species interact with their environment – increased in proportion to island size and the number of species present on the island and that the introduction of exotic species significantly increased the overall array of functional types on each island.

Both groups of arthropods play important functional roles: beetles because they are numerous and operate at multiple feeding levels and spiders as top predators. The authors found that functional diversity of both groups increased in proportion to the number of species on the islands and that these trends did not plateau as island size increased.

Moreover, the patterns for exotic species mimicked those of endemic and other native species. As exotics now outnumber native species on these remote oceanic islands, the results also show that the exotics overlapped with and expanded the functional trait space (the overall array of functional types) originally occupied by native species.

The authors caution that their data indicate the islands remain vulnerable to colonization by additional exotic species and urge further research to explore the interactions between native and exotic species and implications for the persistence of island endemics.



Whittaker, R., Rigal, F., Borges, P.A.V., Cardoso, P., Terzopoulou, S., Casanoves, F., Pla, L., Guilhaumon, F., Ladle, R. & Triantis, K.A. (2014). Functional biogeography of oceanic islands and the scaling of functional diversity in the Azores. PNAS - Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1218036111 (IF2013: 9.809; Q1 Multidisciplinary Sciences)