In reply to druridge:
> Beech isnt native throughout the UK
I was talking about this with a friend recently.
It depends what you mean by native. And by beech, for that matter.
https://www.stir.ac.uk/news/2017/07/beech-trees-native-to-scotland-after-al...
Keep in mind, also, that different types of trees have come and gone as the ice has advanced and receded at different points during our current ice age; all trees were invaders at some point, and many have come and gone and come again.