Earlier quoted context omitted.
Also, when these fires burn mature forests, they don't actually burn the huge trees, just the smaller brush. However, they are so hot that they kill the huge, mature trees. So a couple of years later, you have a huge amount of dead trees ready to burn again.
This description is painting with a wide brush across many different western tree species. A douglasfir forest that burns is going to behave much differently than a late-successional hemlock one.
[0] https://www.amazon.com/gp/product/1561583588/ref=ppx_yo_dt_b...