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24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

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What is Phenology?

Cône femelle de mélèze

Phenology is the study of the occurrence of periodic events, generally in the living world, in relation to the seasonal variations of climate.

A phenological event, also called phenological stage, is for example: flowering, colouring of leaves in autumn, arrival of migratory birds, reproductive period, emergence of the adult stages in insects, etc.

The occurrence of phenology events is closely related to the meteorological conditions, and in particular temperature, as well as day length.

Why is phenology important?

Stade adulte de la processionnaire du pin

Changes in the occurrence dates of phenology events directly affect the survival and reproduction of living organisms, influencing food chains, population dynamics and consequently ecosystems functioning.

For example, if a fruit tree blooms much earlier than usual while pollinating insects are not yet active, its flowers are not pollinated and there will be no production of fruit. Once active, insects will have to find another resource which will potentially affect their own phenology, survival and reproductive success.

Phenology is therefore a key variable in determining:

  • Climate-related risks in agro-ecosystems (e.g. frost damage and drought)
  • Agro-ecosystem productivity and populations’ survival
  • Distribution of species and cultivated crops
  • Levels of interaction among species (host/pathogen, plant/pollinator, prey/predator, etc.)