Tree Surgery Lesson

I'm part of a volunteer project to build a mountain bike park up in the woods just outside Pickering, and some weekends I bob up to help out with a bit of manual labour (not my forte, it has to be said). A few days previously we'd had a very tall, very old tree fall down in the high winds, and when I went up there was a forestry guy with a chainsaw chopping it up into manageable chunks so we could get it out of the way.

I was fascinated by the insides of the tree in question -- seemed perfectly healthy on the outside, but as shown here, was basically being held up by a thin outer shell and the bark. Within the dark ring it was rotten -- the wood was like a wafer biscuit, just crumbled in your hand. Hopefully it's the only tree like this...!!