When hiking through a forested area which has been burned, I’ll sometimes see dead, burned trees still standing even though it has been years or decades since they have been burned. One thing unique about these trees is that they typically have a golden brown appearance, which looks to me like wood that has had oil applied to it. This got me wondering if the fire could have created some kind of preserving oil or resin in the pine wood itself. Since turpentine is made from pine sap, could the heat of the fire create turpentine or a similar substance in some of the trees which keeps them from decaying long after they have died?
Pine trees around here (P. sylvestris) often stay standing long after they are dead, even without any burnin’ goin’ on. Around 200 years, lest a storm knock them over. This due to the high pitch content and the resulting rot resistance of pine heartwood.
Another contributor to preservation of dead trees in situ is that rot comes largely from the action of living organisms. Fires that are hot enough to char the wood but not burn it, help to sterilise it of microorganisms, make the wood less yummy in future, and also kill surrounding ground where a lot of wood and humus feeding organisms would otherwise be lurking.
A hot fire kills a lot more than just trees and wildlife, its like a nuclear bomb has gone off for much of the ecosystem.
Sylvestris, Scots pine, Scotch pine, Baltic pine. It grows in the higher latitudes.
I think thats the clue, the ones that stay standing are not the plantation quick growers.
Sylvestris is known to live for 700 years, but its a slow grower… its not going to be used for plantations.
The slow grower is likely to survive a fire, and it is likely to resist rotting away after death.
Some wood has so much oil in it, that they used it as self lubricating material, like for an axle, where no lubrication can be kept or added. Such as for a clock, the idea that someone lubricating it would disturb the operation …
I don’t think the forest fire “sterilises” the wood, because the living tree is already sterile.
The rainforest would have the situation that a dead tree is broken up quickly by rot and other plants but in a rainforest even healthy trees are attacked by parasitic lifeforms… the vines, ferns, other trees… There can be slow growing, long living trees in rainforest, but they would have to be the ones that resist rot and attack, both before after death…
But it would basically cook/sterilize whatever was living in or on the tree; then do a number on at least the exterior layer of the tree wood, so that the wood is less tasty to new incoming tree predators…thus giving them nothing to chew on so no way to help dispose of the tree?
Quite simply timber is a long lasting substance. That’s why we use it as a construction material.
Moisture is the enemy of wood and a standing tree is going to remain relatively dry.
The tree is still standing for the same reason a fence post is still standing.
This is not entirely true. Logs used to be kept in a mill pond to prevent them splitting prior to milling.
I have some recent experience of this in that I am involved in a large scale rehabilitation/reconstruction of an 1876 windmill, with almost all parts made of wood.
The windshaft (the almost horizontal piece to which the sails attach) had several candidate trees, including one standing dead and one toppled and underwater.
Water is not the same thing as moisture.
Dampness combined with oxygen creates conditions ideal for organisms to attack wood.
Total immersion is a totally different thing, and indeed can actually create its own form of preservation particularly if the water is low in oxygen.
Logs immersed in a mill pond are not merely “moist”, plus they would only be in the mill pond for days or weeks not years.
It’s also true that once trees lose their leaves, they are much harder for strong winds to blow over. It’s the leaves that make them so top heavy, especially when wet.
We are about to put in a new deck, and after looking at pressure treated, cedar, and composite we have decided to use a heat treated lumber from a company called Thermory.
This goes beyond kiln-drying, they heat the material at a temperature below combustion for an extended period of time. This causes the wood to partially polymerize without changing the appearance, increasing the rot and bug resistance. I believe this is similar to the effect of a forest fire where the non-charcoalized wood is still preserved.
When I walk through an area which has had a fire relative recently, there are typically three kinds of standing, dead trunks I see: Deeply charred, white/grey, and golden brown. But it seems like it’s just these golden brown ones which last for decades. I’ve even been in areas where they are still standing even after 100+ years. The charred and grey ones are long gone, but the golden brown ones are still there and look amazingly good considering their age. I’m guessing that the heat of the fire on those trees was just in this sweet spot to cause a preservation effect in the wood the same way the heat treated technique does.
Here’s a redwood still “standing” 55 million years later:
Jus’ sayin’.
Ackshually, it was probably buried upright in a landslide, but who can say how durable a thing wood is?