What are these - tree related

[Spare tyre]

Lots of these in a chopped down trees roots

Is it to kill the root off

Was on a foot path

[davhill]

Something to assist a tree surgeon in the climbing?

[randlemarcus]

Something to help the stump killer penetrate?

[curlie467]

Yep, ecoplug tree killer.

[Spare tyre]

Thankyou all