Way back when I started out thats what sustained me, for nearly 3 years! Standing dead oak from gypsy moth kill.
Along those lines. The first year I had to collect firewood alone our tree lot didn’t have any dead oaks left to cut. Decided to go after the green living “leaners”. Working by myself I cut and stacked rounds in the woods under the canopy to collect later. As life would have it I didn’t have enough time that winter to bring them out of the woods. They stayed in the woods all that summer, collected them in the fall. Strangest thing I noticed how light they were when I went to get them. Now this was before I analyzed much of anything I was doing. No moisture meter, no thinking, just work. But I was awake enough to be surprised at how light they were. Can’t explain why but it was weird and not what I expected at all.
Short on firewood for my own use years ago, I turned to a standing dead oak. It had been dead for years to the point only the trunk was left. Much to my dismay, when I ran the rounds through the splitter, water came out each time. It was almost as if it were more wet than a live oak tree and the wood wasn’t usable until the following winter.