Phenology

Plant phenology is especially important in that it records the points in time at which certain clearly identifiable growth stages occur in specific plants throughout the year on an annual basis. These so-called phenological phases include leaf unfolding, flowering, fruit ripening, leaf discolouration and leaf fall.

MeteoSwiss has been operating its phenological observation network since 1951, which now comprises around 160 stations throughout Switzerland. Some 26 different plant species are monitored in order to describe vegetation development. Moreover, there are two very long phenological measurement series in Switzerland: The timing of horse chestnut budbreakhas been recorded in Geneva since 1808, while cherry-tree blossom timing has been recorded in Liestal since 1894. Observation series that go back that far are very valuable. Since vegetation development is strongly dependent on temperature, plants are good indicators of climate warming.