Annals of Botany

Climate change refugia and species diversity in Eugenia

Predicted regions of historical stability in the Phylocallyx clade across the Quaternary
Predicted regions of historical stability in the Phylocallyx clade across the Quaternary, based on summed predicted occupancy of the clade across current (0 ka pre-industrial), mid-Holocene (6 ka BP), Last Glacial Maximum (LGM; 21 ka BP) and Last Interglacial (LIG; 130 ka BP) climatic scenarios. Areas in red are those where all species of the Phylocallyx clade are predicted to occur during all four time periods and represent postulated refugial areas for the Phylocallyx clade. Maps are for (a) South America, (b) central South America. Brazilian states are labelled as follows: Amazonas (AM), Bahia (BA), Ceará (CE), Distrito Federal (DF), Espírito Santo (ES), Goiás (GO), Maranhão (MA), Minas Gerais (MG), Mato Grosso (MT), Mato Grosso do Sul (MS), Pará (PA), Paraná (PR), Piauí (PI), Rio de Janeiro (RJ), Rio Grande do Norte (RN), Rio Grande do Sul (RS), Rondônia (RO), Santa Catariana (SC), São Paulo (SP), Tocantins (TO).

Eugenia is the most species-rich Neotropical genus. This ‘Research in Context’ article explores the extraordinary evolutionary success of Eugenia sect. Phyllocalyx using a phylogenetic framework, molecular dating, ancestral area reconstruction and ecological niche modelling.

Phylogenetic relationships reveal that Eugenia diversified most rapidly within the eastern tropical American forests, dispersing twice to the cerrado and once to the southern Amazon, and exhibiting different species composition from north-eastern and south-eastern Atlantic forests. De Oliveira Bünger et al. suggest that sites of climate stability provided a refugium in the biodiversity hotspot of the south-eastern Atlantic forest during the Quaternary, thereby contributing to elevated species diversity.