Romero G. Q. auteur aut IRD Marino N. A. C. auteur aut IRD MacDonald A. A. M. auteur aut IRD Cereghino R. auteur aut IRD Trzcinski M. K. auteur aut IRD Mercado D. A. auteur aut IRD Leroy Céline auteur aut IRD Corbara B. auteur aut IRD Farjalla V. F. auteur aut IRD Barberis I. M. auteur aut IRD Dezerald O. auteur aut IRD Hammill E. auteur aut IRD Atwood T. B. auteur aut IRD Piccoli G. C. O. auteur aut IRD Bautista F. O. auteur aut IRD Carrias J. F. auteur aut IRD Leal J. S. auteur aut IRD Montero G. auteur aut IRD Antiqueira P. A. P. auteur aut IRD Freire R. auteur aut IRD Realpe E. auteur aut IRD Amundrud S. L. auteur aut IRD de Omena P. M. auteur aut IRD Campos A. B. A. auteur aut IRD Kratina P. auteur aut IRD O'Gorman E. J. auteur aut IRD Srivastava D. S. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Changes in global and regional precipitation regimes are among the most pervasive components of climate change. Intensification of rainfall cycles, ranging from frequent downpours to severe droughts, could cause widespread, but largely unknown, alterations to trophic structure and ecosystem function. We conducted multi-site coordinated experiments to show how variation in the quantity and evenness of rainfall modulates trophic structure in 210 natural freshwater microcosms (tank bromeliads) across Central and South America (18 degrees N to 29 degrees S). The biomass of smaller organisms (detritivores) was higher under more stable hydrological conditions. Conversely, the biomass of predators was highest when rainfall was uneven, resulting in top-heavy biomass pyramids. These results illustrate how extremes of precipitation, resulting in localized droughts or flooding, can erode the base of freshwater food webs, with negative implications for the stability of trophic dynamics. The amount and frequency of rainfall structures aquatic food webs. Here the authors show that in tropical tank bromeliads, lower trophic levels are more abundant in stable rainfall conditions, while biomass pyramids are inverted in conditions with periodic droughts. specialized AMERIQUE DU SUD AMERIQUE CENTRALE ARGENTINE CARDOSO ILE COLOMBIE COSTA RICA GUYANE FRANCAISE PORTO RICO BRESIL MACAE CARDOSO ILE 082 076 036 062 021 11 1 [8 p.] 2020 2041-1723 https://www.documentation.ird.fr/hor/fdi:010079373 10.1038/s41467-020-17036-4 2041-1723 [F B010079373] https://www.documentation.ird.fr/hor/fdi:010079373 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers20-08/010079373.pdf IRD - Base Horizon / Pleins textes 2020-09-17 2025-02-24 fdi:010079373 fre