Format: ORAL

Olivier Maurin1, Artemis Anest2,3,4, Flix Forest1, Ian Turner5,6, Russell L. Barrett7, Robyn C. Cowan1, Lijia Wang8, Kyle W. Tomlinson2,9, Tristan Charles- Dominique4,10

1 Royal Botanic Gardens, Kew, Richmond, Surrey, UK 2 Center for Integrative Conservation, Yunnan Key Laboratory for Conservation of Tropical Rainforests and Asian Elephants, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Menglun, Yunnan, China 3 University of Chinese Academy of Sciences, Beijing, China4AMAP, Univ Montpellier, CIRAD, CNRS, INRAE, IRD, Montpellier, France 5 Singapore Botanic Gardens, National Parks Board, Singapore, Singapore 6 Singapore Botanical Liaison Officer, Royal Botanic Gardens, Kew, Richmond, Surrey, UK 7 National Herbarium of New South Wales, Australian Botanic Garden, Mount Annan, New South Wales, Australia 8 University of Michigan School of Public Health, Ann Arbor, Michigan, USA 9 Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Menglun, Yunnan, China 10 Centre National de la Recherche Scientifique (CNRS), Sorbonne University, Paris, France

Certain plant clades are distributed across every continent, occupying various contrasting biomes. Within these globally distributed clades, the ecologically dominant Combretaceae family shows intercontinental disjunctions. Fruit morphology in Combretaceae suggests various seed dispersal modes, potentially explaining the observed geographical patterns. To enhance our understanding of the mechanisms that have facilitated such distribution, this study explores the dispersal strategies of the Combretaceae family, the acquisition of new modes throughout their evolutionary history, and their impact on present and past plant biogeography. The study integrates data on natural distribution, biomes, and dispersal types into comparative phylogenetic analyses. Estimates of the ancestral distribution of Combretaceae suggest a Gondwanan origin for this family, with minimal transitions between different biomes. Our findings indicate that drift fruits, dispersing seeds by water, played a critical role in colonising new continental lands. Conversely, biome shifts appear unaffected by dispersal strategies. The study highlights a dispersal mode paradox, wherein specialised modes of seed dispersal can facilitate intercontinental dispersal but limit colonisation of new biomes and strengthen biome conservatism. Our study emphasises the implications for species preservation in changing environments and the importance of understanding the relationship between plant distribution and dispersal modes for effective conservation efforts.