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Question from Rick, Bountiful, UT (received 3/24/20) -

I have some very sickly pine trees. A brief description is as of this year when I began to notice issues, first was the needle loss in a couple of the large trees, 80 to 90% has or is in the process of shedding. Also a couple and now 4 other pines are showing brown/yellowing in the last month. I looked closely and found a spongy feel in the bark of one type of pine, some bore holes in another. USU Forestry was mentioned to me by an alumni that said to get your recommend, he gave me his diagnosis as well.

Again, Thanks!

Rick

Answer from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 3/25/20) -

Rick,

There are a few things going on here. The first photo on the right has a nearly dead blue spruce on the left, then a pine (probably an Austrian pine) right of middle, and another blue spruce on the right. That looks OK, though maybe growing fairly slowly. I can’t tell what is going on with the spruce but I would bet that it is either soil (and therefore root) disturbance, and/or water stress. And if it is water stress then bark beetles could be involved. It looks like it has been growing slowly for many years (maybe 10). It would be helpful to know how long ago the tree’s growth slowed down. This can be done by photographing fairly closeup the length of a good-sized branch from tip to trunk, overlapping the photos if you need to so I can see the point on the twig/branch where growth started from each year.

The other problem I see is a nearly dead bristlecone pine in the other two photos. I am guessing that it also is not getting enough water, though it also may have borers/bark beetles. There also is a very small spruce that has been shaded out by other trees.

So send me some more photos and I will see what I can do.