Master Gardener - Mature Doug Fir stump rot
I cut a mature Doug Fir some years ago whose roots are intertwined with a larger Doug Fir. They almost emerge from the same base. The stump is at ground level and is rotting. I am concerned the rot will affect the remaining tree. Can I do anything to stop the rot?
Typically wood decay organisms that focus on dead trees won't impact live trees unless there is a wound present. The key would be if there are grafted parts of the two trees. It might be prudent for you to try to clear away some of the decaying roots and see if it is impacting the other tree. My guess is that it isn't, but that is of course without seeing it, but I agree it could be possible though unlikely. The only caveat is that if there was laminated root rot, that can transfer to live trees. So it depends on why the first tree was cut, but the answer is "probably not"