https://web.archive.org/web/20151204221 ... 181027.pdf
Use of Fire in Land Clearing
proper ignition techniques important requirements for successful management of controlled burns
Successful ignition starts a controlled fire at a time and place, and in such a way, that it spreads over the entire burn area and consumes or kills undesired vegetation. In addition, prompt and certain ignition reduces the probability of escape, makes the fire easier to control, and may reduce the over-all cost.
Ignition is not a serious problem if the burn area has been selected and prepared to approximate ideal characteristics with fine, dry fuels adjacent to the control line, up-slope into the burn area, and air movement into the burn. However as actual conditions deviate from these ideal characteristics, prompt and certain ignition becomes more difficult. In fact some of the controlled burns fail because brush can not, be made to burn under existing conditions. Certain ignition techniques may broaden the range of conditions under which ignition is possible...
It goes on to discuss such techniques as the use of weed killer weeks in advance to create fire lines and ways to overcome other difficulties. Regarding those particular trees, I didn't mention the discussion below the twitter post, I left it for people who are interested, but generally observations were while the type of fire we see in those trees can happen naturally, the circumstances needed to create the phenomenon are so rare, you'd maybe get at most one or two trees displaying that effect in a whole forrest fire. Here we see six trees in a group all burning from the inside out.
Their discussion suggested energy weapons or aluminium from chem-trailing causing the trees to burn from the inside. I think both are more fantastical than are necessary to explain the unlikely event. It would seem if it can happen in nature, it can also be mimicked on purpose by people. And if it can be mimicked, it can be used purposely. That's my reasoning, and while I haven't got a tree example, I have seen the "wick effect" demonstrated to explain spontaneous human combustion. Once you are able to start the burn, it will slowly consume the object without much surrounding damage.
Wick Effect: The Possible Explanation Behind Spontaneous Human Combustion
https://www.stillunfold.com/science/wic ... combustion
In a 1963 experiment conducted on the wick effect, the lecturer of forensic medicine at Leeds University, Dr. D J Gee, investigated the death of an old woman whose entire body had burnt (except for the right foot) and was found on the hearth. Apart from the soot-covered furniture and blistered paintwork, there wasn’t much damage.
Gee said that when the woman fell onto the hearth, the embers set fire to her hair after which the body was gradually consumed since the body burned its own fat like a candle.
As an experiment, some amount of human fat was taken and wrapped in cloth so as to simulate clothing. A bunsen burner flame was then applied to the candle. Because of the high water content of human fat, the flame had to be held on the candle for more than a minute before it would catch fire:
"One end of the candle was ignited by a Bunsen flame, the fat catching fire after about a minute. Although the Bunsen was removed at this point, combustion of the fat proceeded slowly along the length of the roll, with a smoky yellow flame and many productions of soot, the entire roll is consumed after about one hour."
This somewhat indicates the slow speed at which the wick effect will occur.