3 year old Bigleaf maple has blackened and shrunken bark that has developed over approx 6 week period. Doesn't seem to have affected overall health of tree (yet), but appears to be almost entirely girdling stem. I'm on the BC coast in a dryish fir/hemlock zone.
Maybe this. http://plant-disease.ippc.orst.edu/ShowDisease.aspx?RecordID=708 Same site has pages on other maple diseases.
