Help wanted in solving maple mystery

OLIVER RACKHAM is the acknowledged guru of woodland ecology and all things to do with trees.

His knowledge is immense. I was reading one of his books the other day and a sentence jumped out at me.

“Maple is supposed to be an introduction in Ireland, but on not very good grounds; its pollen and wood have been found in prehistoric contexts.”

This was news to me. There’s no doubt that the tree Rackham is referring to is Acer campestre, the field maple, sometimes known as the English maple. It’s an attractive, medium-sized tree that’s easy to recognise when it’s in leaf. The leaves are a classic maple or sycamore shape but very small, no bigger than a match box. In the south of England it’s common in mixed woodlands and mature hedgerows and the definitive Collins Tree Guide says it’s native in England and Wales, with the implication that it’s not in Scotland and Ireland.

Recently it has become quite popular as a street tree or for planting in parks and gardens. But field maples naturalised or growing wild in a woodland or hedgerow situation are very rare in Ireland. In a lifetime of tree-hunting I have only found them at two locations in the entire 32 counties.

Both these locations had originally been ‘demesne woods’, in other words they had surrounded a large country house (actually a castle in both cases). I assumed that a rich and powerful landowner with a liking for exotic trees had imported them from England or Wales at some time in the past and they had managed to become naturalised.

I like the notion that I might be wrong. Field maples are attractive trees and the idea we may be able to add them to our very small list of native species is appealing. But what is the evidence? Oliver Rackham is an academic botanist so the sentence I quoted had a footnote. “Information from Richard Bradshaw, citing M. O Connell for the pollen.” Unfortunately, I haven’t been able to track down this reference.

So I’m appealing for assistance from tree-lovers. Two things would help me to solve the mystery of whether or not field maple is a native Irish tree. First, any records of trees around the country that have the appearance of being self-sown and therefore either native or naturalised; second, any information on the Richard Bradshaw and M O’Connell mentioned in the footnote.

On the whole we have a good idea of which tree species are native to this country and which were introduced. This is mainly because we have so many bogs and peat is very good at preserving ancient tree pollen, and sometimes entire trees. But there are still a few question marks beside species that produce very little pollen – these are mostly insect-pollinated rather than wind-pollinated trees.

It was once thought that black poplar might be a rare native in the Shannon basin. This theory now seems to be out of favour. Beech is generally regarded as an introduction but there is one intriguing record of a prehistoric beech nut. The species may have established itself here briefly and then become extinct.

The biggest question surrounds Scots pine, which was once common all over these islands. But it died out in England and Wales thousands of years ago, leaving only a relict population in the Scottish highlands. It survived far longer in Ireland than in England or Wales but seems to disappear from the pollen record in the Middle Ages. It probably became extinct but it’s possible a few groves survived in remote areas.

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