Prisoners Of Geography

This is Magnolia Sprengeri in blossom today in the Botanic Garden here in Cambridge.

Apart from the Magnolia there were some hellebores flowering. And the forsythia and plum and cherry were in bloom. Other than that there were no flowers out at all.

Many trees are in bud, with every kind of shape curled up or just spreading their wings, so to speak. There are leaves from needle-like curled leaves to ones as round as buttons. The Hop hornbeam leaves are packed in these little bundles.

And in this ‘almost ready’ scene there were magnolias splashing the scene with gorgeous colour.. And that raises a question. There is nothing to compete with them for the attention of birds and insects to pollinate them. So why make such big showy flowers? Almost any size flower would do when there is no competition.

Is there no competition because they are away from their natural habitat? Would there be competitors there in the country of origin? Where is their natural habitat? What is their country of origin?

Their natural habitat is across much of Asia and the Americas. But not Europe. The reason why there were none in Europe after the last Ice Age is an example of a brilliant story of climate and geography.

Magnolia trees have been found in fossils in Europe dating back nearly sixty million years. But during the the Ice Age the magnolias in Europe were destroyed. Why?

Picture this. The Earth is cooling and the Ice Age is approaching. The ice sheet spreads southward from the North Pole. The trees retreat because their desired habitat is where it is warm. Southwards they travel in Asia and the Americas. And they can do so because the mountain ranges run north-south.

But in Europe the ranges (the Jura, the Alps, the Dolomites, the Carpathians) run east-west, and they block the escape route for the trees. With nowhere to go, the tree species dies out. And it is not until they were reintroduced in modern times that magnolias found a home again in Britain.

More magnolias

On the walk home I came across another Magnolia in bloom in a garden in a narrow alley in Cambridge. How many more might I see if I were to go looking?

Attribution

The information about effects of the Ice Age in Europe versus Asia and the Americas is in the section on native and ‘foreign’ trees on page 10 of ‘An Introduction to Trees of the Cambridge University Botanic Garden‘ by Ann Johnston..

She also describes how Britain suffered more than Continental Europe ‘ when the English Channel was formed in terms of trees ‘travelling.

My opposition to the UK leaving the European Union was based on similar thoughts – of being cut off from the pollination that different views can bring to the table when there is a table around which the views can meet. Instead, the UK (England, really) chose to pull up the drawbridge on Continental Europe and feed on its own thoughts alone.