Cutting through tree-trunks

from bark to bark,

we’ll see lots of circles

in light-wood and dark.

Light-coloured bands

mostly grow summer-spring

while autumn to winter

grows thin, darker rings.

Tree-rings grow wide

when it’s wetter and hot,

but tend to grow narrow

whenever it’s not.

Decoding these bands

in an ancient tree

can tell us the climate

historically!

First published in Double Helix (Oct 2021)

Reproduced with permission of CSIRO

www.doublehelix.csiro.au

Decoding tree rings