Hello,

 Your white pine (Pinus strobus) is going through a cycle that evergreens go through when they shed the interior needles.  New growth on an evergreen takes place at the tips of the branch. Although we think that needles of evergreens are permanent, the interior needles die and are shed leaving the new growth at the tip of the branch. This is a natural progression and does not mean that there is something wrong with the tree.  Read the attached article for more information.

 https://www.canr.msu.edu/news/why_are_my_evergreens_losing_their_needles

I hope this answers your question.

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