Bache Hill and the Whimble 1
Image by thesweetcheat

That sounds very weird and pointless, and very sad about the trees too. No idea why someone would do that, you must be annoyed (probably not a strong enough word).

Still not sure why you think it might be druids though? I thought they were keen on tree groves and natural order, although I don't really have any idea what druids believe in.

ask a stupid question, it's not just to protect the barrow by stopping the tree growing into it (I can't quite work out how near it is), or to bring some sunlight to it, opening the canopy?

Cutting a cross into the stump would surely be to help it rot, I'm sure that's quite normal isn't it?

are they fir trees? I know in deciduous woods it's good to keep rotting wood piles for the benefit of Creatures, could that be the motivation?

sorry if this all sounds unlikely to you, it's only me making suggestions while not being able to visualise the scene so well.