Does this look like symptoms of Scweinitzii?

Asked September 3, 2019, 10:46 PM EDT

I observed a large (>36" dbh) Douglas-fir with very apparent butt swell and resin build up along the trunk. At the base I observed what I thought might be a conk, but upon braking it apart it appeared to be old resin build-up. The attached photos show what I believe to be the resin blocks. One was perched above the soil, but minimal excavation turned up more. It also appears that there was some bark decay just below the soil line (visible with hammer in a photo), which may be from soil being piled on the trunk or root decay. I also stepped in a giant pile of fresh resin that stuck to my foot like a squished soft ball. I'll likely do a further root crown excavation, but wanted to see if one of your experts could provide guidance on the information I have so far.

Multnomah County Oregon forestry

1 Response

It does look like old resin buildup. I don’t see clear signs to identify cause as to species if fungus. There are many causes of resinous. Diagnosis requires more complete inspection of whole tree situation. Schwienitzii conks are very distinct, velvet top or “cow flop” appearance, on ground or large root surface near base of tree.