Go West, young tree
The forests really are on the move
Did you know that forests can migrate? Look out the window — they’re going now, heading West.
Does that sound crazy? It’s not. Less than 200 years after the American settlers headed West, the trees are following in their millions. And we’re not certain why.
Mass forest migrations have happened before. The most recent ice ages led to vast glaciers, ice mountains, slowly grinding South from the North Pole, destroying everything in their path. People in what are now Europe and the USA moved South to keep ahead of the killing ice sheets, and animals followed. And so did the trees.
How? How does a forest move? Slowly, too slowly for us to notice with our high-speed jerky motion. But not exactly crawling either — a forest can move up to 30km (19 miles) over a decade. Let’s not get all Ent about this, there’s scientific proof about how the forests escaped the ice.
Individual trees have to stand still of course, but seeds, nuts, pollen and everything else were sent South with animals, birds and breeze. The trees left behind died, crushed and frozen by the ice mountains, but the forest itself recolonized somewhere warmer and safer. (Actually the story in Europe was darker and scarier than that, but that’s not a story for bedtime, children, but for another time.)
The reverse is happening now. As the climate warms and other factors come into play the trees are once more heading North, where it’s cooler. At least, that’s what scientists in America thought, until they looked at the latest data sets.
And the data showed that most of the trees aren’t heading North, they’re heading West.
We’re not sure why, but it seems likely that the evergreen trees are heading North for the cool, but the deciduous trees are going West because they’re chasing better rainfall rather than cold. (We’ll have to wait for more data from Europe to see if this is part of a wider migration.)
There’s plenty of debate and conflicting data as to exactly what is happening, but we’ll have to wait patiently, in tree-time, to find out exactly where the forests are going and why. But one thing is for sure — they’re going.
Graham Scott is the author of the children’s Treelogy series, with the Banished to the Forest and Defending the Forest now available through Amazon.co.uk or Amazon.com or the publisher Phillimore Book Publishers.