Here's a mystery (to me, anyway.)

Still delving. Might be something to do with South East Water.

http://www.southeastwater.co.uk/media/6253/12139 SEW CAPEX Swinley Forest New version leaflet March 2015.pdf

Quote:
"Stag beetle
We discovered a colony of stag
beetles in a rotten old tree stump.
The adults, their larvae and the
entire stump have been moved to a
safe location.
We have also moved additional tree
stumps away from our construction
area and laid them on the forest
floor to create more safe havens for
stag beetles during our works."

If it is SE Water, I think they've made a mistake in lifting the trunks off the ground. They should have been sunk into the ground by 6 inches.

 

Why not contact them to see if it's them, and advise them if need be?

 

Ah, but it turns out that there other types of Stag Beetles besides the one type I know.

See here.

And these smaller ones don't need the trees stuck in the ground.

 

The answer is just in from the Crown Estates from someone who had contacted them to ask if the trunks were an Art Project. So they're not Oak but Sweet Chestnut. Who spotted that? Dunno where they get a Bat Roost from. :(




"From Crown Estate

"

Not an art project but an attempt to conserve the habitat of the sweet chestnut stems that were felled as part of the new south east water pipeline. The sweet chestnut trees sadly had to be felled as they were in the wayleave of the new pipe. The decaying timber is valuable for all kinds of invertebrates, bats and birds and will hopefully continue to rot down and provide an excellent habitat. the reason behind hanging it upright is that it will rot in a completely different way standing then it would do laying down. There will be a different fungal association and it should also help to provide a bat roost."

 

Just seen your last post @kindredspirit

Well found out