Human skin isn't the only thing that can change color after facing the cold. Trees and shrubs change colors, too, taking on a special blue tinge after they are sampled and stained. That’s according to a new study in Frontiers in Plant Science, which found strange blue rings in samples of trees and shrubs from the northern treeline in Norway.
“Blue rings look like unfinished growth rings, and are associated with cold conditions during the growing season,” said Agata Buchwal, a study author and dendrochronologist at Adam Mickiewicz University in Poland, in a press release.
In fact, the study authors say that their findings testify to two cold seasons almost 150 and 125 years ago, perhaps caused by a pair of volcanic eruptions.
