Why do trees have rings signifying their age?

Question

Is it like a “this is when it was really cold” or some other variable that causes the change?

In: 2

Answer 1

I think you have the right idea.

Trees grow faster when it’s warm and wet and slower when it’s cold and dry, so the thicker the ring, the faster the tree was growing at that time.

When you look at the pattern of thick and thin lines, then you can get an idea of roughly how many seasons the tree has grown through which can give you an idea of how many years old it is.