News January 2024

After drought earlier or later leaf discolouration in autumn?

In order to better understand the potential impact of climate change on our forests, we studied how common dogwood, a common shrub species, responds to a period of water shortage followed by summer re-watering. Young plants from a local Flemish and a Spanish-Pyrenean origin were part of the trial.

We observed that autumn discolouration occurred earlier in plants that showed no to little leaf desiccation after the summer drought compared to those that had had no water deficit. Plants with severe to total leaf desiccation formed new shoots with leaves after the drought period. They showed later leaf discolouration in autumn. We observed no shift in the timing of autumn leaf discolouration in plants where about half of the leaves had withered due to water deficit.

These results suggest two different plant recovery strategies after drought, both activated in the same trial:

  • The earlier leaf discolouration is presumably an acclimatisation in which the plant arms itself against possible new droughts.
  • The delayed leaf discolouration allows plants to repair damaged tissues before winter sets in, with the risk of even stronger decline or even mortality in a new drought.

Which strategy took effect depended on the severity of drought stress. The two strategies levelled each other for the plants with intermediate drought symptoms.

We also observed a difference between the two provenances: the earlier leaf discolouration was activated earlier in the Pyrenean provenance. There was no difference in timing for the delayed leaf discolouration.

Kristine Vander Mijnsbrugge

Read more: Kristine Vander Mijnsbrugge, Jasper Vandepitte, Stefaan Moreels, Victor-Vasile Mihaila, Liselotte De Ligne, Eduardo Notivol, Joris Van Acker, Jan Van den Bulcke, Timing of autumnal leaf senescence in a common shrub species depends on the level of preceding summer drought symptoms, Environmental and Experimental Botany, Volume 216, 2023, 105539, ISSN 0098-8472,


  • {{validation.errorMessage}}