title: Photoperiodic induction of synchronous flowering near the Equator.
abstract: In tropical rainforests, 30-65% of tree species grow at densities of less than one individual per hectare. At these low population densities, successful cross-pollination relies on synchronous flowering. In rainforests with low climatic seasonality, photoperiodic control is the only reliable mechanism for inducing synchronous flowering. This poses a problem because there is no variation in day length at the Equator. Here we propose a new mechanism of photoperiodic timekeeping based on the perception of variation in sunrise or sunset time, which explains and predicts the annually repeated, staggered, synchronous and bimodal flowering of many tree species in Amazonian rainforests near the Equator.
authors.affiliation: Biology Division, University of Kansas, Lawrence, Kansas 66045-7534, USA. borchert@ku.edu
authors.forename: Rolf
authors.initials: R
authors.lastname: Borchert
authors.forename: Susanne S
authors.initials: SS
authors.lastname: Renner
authors.forename: Zoraida
authors.initials: Z
authors.lastname: Calle
authors.forename: Diego
authors.initials: D
authors.lastname: Navarrete
authors.forename: Alan
authors.initials: A
authors.lastname: Tye
authors.forename: Laurent
authors.initials: L
authors.lastname: Gautier
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Spichiger
authors.forename: Patricio
authors.initials: P
authors.lastname: von Hildebrand
mesh_terms: D003105:Colombia; D003364:Costa Rica; D035264:Flowers / Q000502:physiology* / Q000528:radiation effects; D005843:Geography; D035322:Melastomataceae / Q000502:physiology / Q000528:radiation effects; D035924:Montanoa / Q000502:physiology / Q000528:radiation effects; D017440:Photoperiod; D012098:Reproduction / Q000502:physiology / Q000528:radiation effects; D012621:Seasons; D013472:Sunlight; D013997:Time Factors; D014197:Trees / Q000502:physiology / Q000528:radiation effects; D014329:Tropical Climate