Remember xylem and phloem from elementary school science class? I do. Which one do you think is responsible for making the foam in this video? I was unsequestering some carbon yesterday as part of landscaping-by-elimination. The top end of this oak tree was in the fire. Looks like water was turning to steam inside the xylem and phloem, forcing unheated sap and steam out the cut end. Phloem has all the nutrients in it, so I'm guessing that's the source of the foam. And the xylem is probably just making the hissing clear liquid. This is based on plain reasoning because my google search on this was not satisfying. Any botanists out there to confirm this hypothesis? All this sap with foaming potential kind of illustrates how trees in the south just don't pay any attention to winter time.
Sorry it's so short. The fire flared up right after I started recording and made a loud noise that resulted in the iPhone microphone clipping. I can't stand that sound so I trimmed the video short. I should have deleted the fade in and out so you could at least look at it after it ended. There are no do-overs on Vimeo unfortunately.