I’ve had this photo a couple months; never got around to trying to find out why a fire-damaged pine tree was foaming one day.
“…what you were looking at is a common bacterial disease among deciduous trees called slime flux. Now, if that is not a disgustingly descriptive name I do not know what is. Another name is wetwood because of the water-soaked marks on the trunk of infected trees.
“There are several bacteria that are associated with this disease and no one single organism has been identified as the main culprit. As the bacteria grow inside the tree (usually in damaged areas of the wood), carbon dioxide gas is released as fermentation occurs.
“This release of gas increases the pressure in the tree and forces sap to the outside, resulting in wet areas on the trunk. This is called fluxing and results in large, dark regions on the trunk once the flux is exposed to air. These wet areas become breeding grounds for other microorganisms – as alcohols are produced in this mess, bubbles or foam form as well as foul smells.
“I am surprised you did not see many insects feeding on the “brew” because this alcohol mixture attracts many bees, beetles and other larval forms to the concoction. Fortunately, the insects do not do any harm and there has not been any indication that the insects can act as a vector for the disease and spread it to other healthy trees in the area.”
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