The Andes through time and the evolution and distribution of Andean floras

The Andes are the world’s most
biodiverse mountain chain, encompassing a complex array of ecosystems from
tropical rainforests to alpine habitats. Here, we provide a synthesis of Andean
Tracheophyte plant diversity by estimating a list of all species with publicly
available records, which we integrate with a phylogenetic dataset of 14,501
Neotropical plant species in 194 clades. We find that (i) the Andean flora comprises
at least 28,691 georeferenced species documented to date, (ii) Northern Andean
mid-elevation cloud forests are the most species-rich Andean ecosystems, (iii)
the Andes are a key source and sink of Neotropical plant diversity, and (iv)
the Andes, Amazonia and other Neotropical biomes have had a considerable amount
of biotic interchange through time.