Probably because this tree is tired of doing this year after year for 1000 years)Trees live a long time, some for thousands of years. Why does a tree live for 1,000 years, then die at 1,001? Why not just keep doing what it's doing? What's the mechanism of death?
I believe this is true. I read something similar which explained that the cells which our bodies are constructed from are never anymore than 10-15 years old at any given moment in time. Therefore, a 75 year old person, for example, can make the argument that they really aren't any older then 10-15 years. But as you mentioned, the copies that are created become worse over time, much like a full size video being shared millions of times on the internet and how each successive copy is inherently of lesser quality than the one it was copied from. The average person is exposed to countless toxins and threats. If you want to get really technical, there's free radical and damage theory...I like the question and the answers.
I’ve read that in humans all dna breaks down as cells are copied so many times over. The cells in my body have probably been copied millions of times over from the original. X ray radiation (sun) and just plain old background radiation can cause an imperfect copy of the dna in the cell causing mutations/failures. I’m assuming the tree cells experience the same.