Letter

Photoperiodic induction of synchronous flowering near the Equator

Received:
Accepted:
Published online:

Abstract

In tropical rainforests, 30–65% of tree species grow at densities of less than one individual per hectare1. 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 flowering2,3. 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.

  • Subscribe to Nature for full access:

    $199

    Subscribe

Additional access options:

Already a subscriber?  Log in  now or  Register  for online access.

References

  1. 1.

    et al. Tropical tree diversity: Results from a worldwide network of large plots. Biol. Skr. Dan. Vid. Selsk. (Copenhagen) (in the press)

  2. 2.

    & Photoperiodism in Plants (Academic, San Diego, 1997)

  3. 3.

    et al. Increasing day length induces spring flushing of tropical dry forest trees in the absence of rain. Trees – Struct. Funct. 16, 445–456 (2002)

  4. 4.

    & Induction of flowering in tropical trees by a 30-min reduction in photoperiod: evidence from field observations and herbarium specimens. Tree Physiol. 21, 201–212 (2001)

  5. 5.

    & Photoperiodic control of seasonal development in tropical stem-succulent trees. Tree Physiol. 21, 213–221 (2001)

  6. 6.

    , , & Environmental control of flowering periodicity in Costa Rican and Mexican tropical dry forests. Global Ecol. Biogeogr. 13, 409–425 (2004)

  7. 7.

    Environmental control of tropical tree phenology (2004)

  8. 8.

    Temporal variation in the reproductive phenology of Montanoa quadrangularis in the Andes of Colombia: declining photoperiod as a likely environmental trigger. Biotropica 34, 621–622 (2002)

  9. 9.

    National Maritime Museum. Timekeeping: the Equation of Time .

  10. 10.

    Periodic leaf-exchange and flowering of trees in Singapore (II). Gardens Bull. S.S 11, 119–175 (1940)

  11. 11.

    , , , & FKF1 is essential for photoperiodic-specific light signaling in Arabidopsis. Nature 426, 302–306 (2004)

  12. 12.

    et al. Photoreceptor regulation of CONSTANS protein in photoperiodic flowering. Science 303, 1003–1006 (2004)

  13. 13.

    Response of rice to small differences in length of day. Nature 183, 413–414 (1959)

  14. 14.

    A possible selective factor in the evolution of fruiting seasons in tropical forest. Oikos 15, 274–281 (1965)

  15. 15.

    Reproduction de la Strate Arborée d'une Forêt Ombrophile d'Amazonie Péruvienne M.S. thesis, Univ. Genève (1985)

  16. 16.

    & Ritmos de reproducción en el estrato arbóreo del Arboretum Jenaro Herrera (provincia de Requena, departamento de Loreto, Perú). Contribución al estudio de la flora y de la vegetación de la Amazonía peruana. X. Candollea 41, 193–207 (1986)

  17. 17.

    & Phenology of tree species in Bolivian dry forests. Biotropica 32, 276–286 (2000)

Download references

Author information

Affiliations

  1. Biology Division, University of Kansas, Lawrence, Kansas 66045-7534, USA

    • Rolf Borchert
  2. Department of Biology, Ludwig Maximilians University, 80638 Munich, Germany

    • Susanne S. Renner
  3. Center for Research on Sustainable Agriculture CIPAV, A. A. 20591, Cali, Colombia

    • Zoraida Calle
  4. Fundacion Puerto Rastrojo, A. A. 241438, Bogotá, Colombia

    • Diego Navarrete
    •  & Patricio von Hildebrand
  5. Botany Department, Charles Darwin Research Station, Galapagos, via AP 17-01-3891, Quito, Ecuador

    • Alan Tye
  6. Conservatoire et Jardin botaniques de la Ville de Genève, Case Postale 60, CH-1292 Chambésy/GE, Switzerland

    • Laurent Gautier
    •  & Rodolphe Spichiger

Authors

  1. Search for Rolf Borchert in:

  2. Search for Susanne S. Renner in:

  3. Search for Zoraida Calle in:

  4. Search for Diego Navarrete in:

  5. Search for Alan Tye in:

  6. Search for Laurent Gautier in:

  7. Search for Rodolphe Spichiger in:

  8. Search for Patricio von Hildebrand in:

Competing interests

The authors declare that they have no competing financial interests.

Corresponding author

Correspondence to Rolf Borchert.

Supplementary information

Word documents

  1. 1.

    Supplementary Discussion 1

    This describes the sun's motion and its effect on time keeping and explains the equation of time (Fig. 3). Websites and references to more detailed descriptions are provided.

  2. 2.

    Supplementary Discussion 2

    This describes the role of the Intertropical Convergence Zone in causing bimodal rainfall patterns at ~4 °N in northern South America and the resulting bimodal flowering periodicity of three drought-deciduous tree species (Figs. 4 and 5).

  3. 3.

    Supplementary Table

    This shows the changes in day length, sunrise and sunset time during 20-d periods around the spring and autumn equinoxes (compare Fig. 1d, f).

Excel files

  1. 1.

    Supplementary Data

    This provides in 6 worksheets flowering observations used for calculation of mean flowering time and standard deviations for Fig. 2a (0 to 5 0S) and 2c.

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.