I'm impressed. I hadn't realized wood fragments from the construction had been recovered.
I'm not sure that they have. I have 'the/my' list of tree ring 'event' dates and anytime I see a date that correlates, I write it on that list, mainly as a reference to myself. I don't remember the source of that date for the construction of Stonehenge. It may or may not be supported by tree ring data, I'll see if I can clarify that.
It looks like I've picked up that date from dendrochronologist Mike Baillie and he does not connect it to tree ring data either. I suspect he has just conveniently 'grabbed' it from someone else just like I did from him.