Format: ORAL

Tammy L Elliott1,2, Daniel Spalink3, Isabel Larridon4,5, Marcial Escudero6, Jan Hackel4, Russell L Barrett7, Santiago Martn-Bravo8, Jos Ignacio Mrquez-Corro4,8, Carolina Granados Mendoza9, Aluoneswi C Mashau10, Katya Romero Soler9, Daniel A Zhigila11, Caroline Oliveira Andrino12, Ana Carolina Galindo da Costa13, Maria S Vorontsova4, Karen L Wilson7, A Muthama Muasya2

1 Masaryk University, Brno, Czech Republic 2 University of Cape Town, Cape Town, South Africa 3 Texas A&M University, Texas, USA 4 Royal Botanic Gardens, Kew, UK 5 Ghent University, Gent, Belgium 6 Universidad de Sevilla, Seville, Spain 7 Australian Institute of Botanical Science, New South Wales, Australia 8 Universidad Pablo de Olavide, Seville, Spain 9 Universidad Nacional Autónoma de México, Mexico City, Mexico 10 South African National Biodiversity Institute, Pretoria, South Africa 11 Gombe State University, Gombe, Nigeria 12 Universidade de Brasília, Brasília, Brazil, 13 Instituto Tecnológico Vale Desenvolvimento Sustentável, Belém, Brazil

Poales, one of the most species-rich orders of plants, often characterise open habitats, enabled by unique suites of traits. We test the hypothesis that key life form traits (photosynthetic system, annual/perennial, insect/animal pollination, epiphyte/non-epiphyte, presence of silica) diverge in different lineages at distinct times and places, leading to spatiotemporal heterogeneity in the diversification of families and the assembly of open habitats. We sampled 42% of Poales species and obtained taxonomic and biogeographic data from the World Checklist of Vascular Plants database, which was combined with trait data scored by taxonomic experts. A dated phylogeny of Poales was constructed using phylogenomic and phylogenetic data. We integrated spatial phylogenetics with regionalization analyses, historical biogeography, ancestral state estimations and models of contingent evolution. Diversification in Poales and assembly of open and closed habitats results from dynamic evolutionary processes that vary across lineages, time, space and traits. Parallel patterns of habitat and trait transitions are evident in the species-rich Poaceae and Cyperaceae families, yet other smaller families display unique evolutionary trajectories. Our results suggest that flexibility in key traits, which is displayed in the most species-rich lineages of Poales, might be an important adaptation allowing transitions between open and closed habitats.