Climate change has been affecting plants over the last century and caused

changes in life history features such as the flowering time. Herbarium specimens provide

a snapshot of the past environmental conditions during their collection. The collection

date in a herbarium specimen is a good proxy to determine the flowering period (phenology).

In this study, phenological data from subarctic plant specimens collected over

100 years were gathered by using one of the largest herbarium databases in the World.

The collection dates of 7146 herbarium specimens were analyzed and significant shifts

in the phenology of subarctic plants were detected. In this study, most of the analyzed

142 species in a subarctic biogeographic region tended to flower earlier in the 1950–2018

period compared to the 1900–1949 as a possible result of the climate change. Flowering

time shifted from 8 to 26 days in some species. Changes in flowering time may

alter species interactions, community composition, and species distribution in a region.

Therefore, results of this study may shed light on the possible shifts in phenology and

plant responses under the climate change.