Rings in Time

I noticed a large pile of felled trees at Beecraigs country park. Drying out before being used for future.
I counted this one and it has 37 rings. I had to find out what the dark line was when it was 23 years old, possibly 2003. That was one of the hottest summers on record, so maybe that's the evidence.

The theme this week is geometric patterns. Might have to use this depending on whether I get any more chances. The circle is after all one of the ultimate geometric shapes.