Birch - my favourite tree!
When I was a kid my father told me to collect birch bark for tinder. And if it was wet, always look for birch as both kindling and fuel. Birch wood burns even if I have to burn green wood.
Birch (old norse bjǫrk - meaning: the pale or light-coloured tree). From the family Betulae. 20-30 % of the weight of the bark is Betuline, a burning Triterpene.
There is betuline in the zap as well. The betuline makes the bark white coloured and protects the tree from sun heating in the winter, thus preventing cell death from high and rapid temperature fluctuation. This is why the bark/paper is so smooth. And it makes the bark and wood burn even when it is soaking wet.
Chaga (birch fungus) grows on birch and converts betuline to betulinic acid which is concentrated in the tissue. Chaga is one of the really good tinders.
In my area quite far north we are completely dependent on this tree type. A lifesaver that gets smaller and smaller the more wind and frost it is in the area. But if trees can grow a place, we'll find birch there. And if we can find it we can get warmth from it.
Things are connected. I feel grateful, blessed and happy when I light a birch fire.