Assessing angiosperm phylodiversity patterns in Argentine phytogeographical provinces using presence-only data

Abstract Studying spatial patterns of biodiversity allows us to infer how different ecological and evolutionary processes have interacted, but also to understand its current distribution in order to preserve it. The Argentinian flora is rich and diverse due to the variety of environments that the country includes. It has traditionally been classified into different phytogeographical provinces, this being one of the most widely used bioregionalization schemes in Argentina. Since these provinces reflect both ecological and historical dimensions, we propose to analyse their patterns of angiosperm phylogenetic diversity using different measures of phylogenetic structure. The results show that phylogenetic diversity and divergence was generally lower in phytogeographical provinces with cold and dry climates (e.g. Puna, Monte, Patagonia, Altoandina). Conversely, in phytogeographical provinces with warm and humid subtropical climates (e.g. Paranaense, Yungas, Chaco), phylodiversity levels were higher. Although these results agree with the ‘tropical niche conservatism’ hypothesis, higher phylogenetic diversity was also found in the Subantarctica province, consistent here with the ‘Austral conservatism’ hypothesis. Differences were also found in the timescales over which divergence accumulates, distinguishing the Yungas from the Paranaense and Subantarctica provinces. This study aims to contribute to the knowledge of biodiversity patterns in the Argentine and Southern Cone flora.