The biogeography of tropical plants with megafaunal fruits
ID: 613 / 447
Proposed Symposium Title: The biogeography of tropical plants with megafaunal fruits
Renske E. Onstein1,2, Seheno Andriantsaralaza3, Onja Razafindratsima4, Andressa Cabral2, Anna Traveset5, Mauro Galetti6
Affiliations: 1 Naturalis Biodiversity Center, Leiden, the Netherlands 2 German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany 3 University of Antananarivo, Antananarivo, Madagascar 4 University of California Berkeley, Berkeley, USA 5 Instituto Mediterráneo de Estudios Avanzados (IMEDEA,CSIC-UIB), Mallorca, Spain 6 São Paulo State University (UNESP), Sao Paulo, Brazil
Plants with megafaunal fruits (>4 cm) have relied on dispersal by megafauna and other large-bodied vertebrates (> 40 kg) throughout their million-year evolutionary history. How megafruit plants have persisted in contemporary ecosystems after the Pleistocene extinction of most megafauna - especially in the Neotropics, Madagascar, and Australasia - remains an evolutionary enigma. By integrating global data on traits, seed dispersal interactions, phylogenies and geographical occurrences for >1500 megafruit plants, we show that many megafruit species (613 species, 40%) interact with contemporary dispersers, including humans, megafauna (e.g., elephants), secondary dispersers (e.g., rodents), or water, providing an explanation for their persistence. These megafruit species often have large geographical range sizes, strongly contrasting the 128 (up to 300) megafruit species that are currently threatened with extinction, suffer from small range sizes, and lack suitable co-occurring dispersers, primarily on (isolated) tropical islands in the Australasia, IndoMalay and Madagascar regions. Our results illustrate how the Pleistocene extinctions and ongoing defaunation limit seed dispersal of many tropical plant populations with megafaunal fruit, but humans may have replaced megafaunal dispersal functions for s subset of taxa.