Phenology is the timing of annually recurrent biological events. These include the timing of spring blossoming, fruit development in summer and leaf colouration in autumn. In animals it can include the timing of migration, hibernation, hatching, and mating.
The timing of these phenological events is controlled by climate.
The longest phenological record derives from the Japanese cherry festival, dating back to the ninth century. The date of flowering, and hence the timing of the festival, has been affected over the centuries by changes in spring temperatures.
In the United Kingdom, the Marsham record comprises two centuries of phenological records captured by generations of the Marsham family, which scientists found captured advances in phenological events driven by changes in temperature and rainfall.
A paper written eight years ago in South Africa showed how apple and pear trees in the southwestern Cape were flowering earlier due to changes in temperature.
These changes in the timing of phenological events are important to monitor. Phenology is argued to be one of the most sensitive biological indicators of climate change. Phenological shifts are often detected long before irreversible ecosystem responses are apparent.
