Scientists from the University of Oxford and the University of Lapland found that low tundra shrubs, many of which are willow and alder species, have rapidly grown into small trees over the last 50 years.
The findings were made across Russia’s northwest Arctic coast, and could indicate what is in store across the rest of the Arctic tundra region.
The researchers say that the darker color of the expanding trees probably means the region will absorb even more heat from sunlight that previously would have been reflected back into space.
This, in turn, could cause the Arctic to heat up even more than the record warming the region has experienced under climate change.
The researchers also say that forests to the south could also expand northward into the tundra as the warming climate allows them to survive in formerly inhospitable environments.