The pines of the Arboretum Park in Seattle are suffering from pine needle fungus which kills the trees and appears to spread among them. 
 

For the past few years park management has been cutting them down as they brown out and die. Now I’m an engineer not a botanist but do find myself observing the stump rings of these cut down trees and what I find is they are all about 85 to 87 years old which matches a period of park development in the 1930’s. 
 

What I see is a clear delineation of growth ring width where they start out quite wide and continue that way for about 60 years then about 25 to 27 years ago there is a marked reduction in growth ring width, it is very easy to see. Every tree that has been cut down shows this, it varies by a couple years where trees higher on the hill show it about 27 years ago while trees toward the bottom of the hill show ir about 25 years ago. 
 

I haven’t found any info that says pine trees slow their growth after 40 years so I see that as an open question? Or am I looking at a change in climate? These are questions for experts to answer, but the change is consistent in its timing and grossly obvious.

RJH Seattle