Until Now
BiologyEnvironment

Redwood forests grow in the polar night

Fossil stumps on Axel Heiberg Island stand where they grew, in forests that lived through months of darkness.

When
Duration
5 million years
Known to
± 3 million years
Era
Eocene, Cenozoic

On Axel Heiberg Island in the Canadian Arctic, whole Eocene forests survive as unmineralised wood — stumps still rooted in their soil, leaf litter still recognisable as dawn redwood, and wood dry enough to burn. Growth rings show large annual increments, so the trees grew fast in the continuous summer light and shut down entirely for the dark half of the year. No modern forest works this way, because no modern climate combines high-latitude light regimes with the warmth to support large trees.

Just before

Just after