As for “how does the combustible material get there”?
I don’t know what process you would think was responsible but I’ll stick with what my Primary School teacher told me.
Grasses and trees grow when there are the required conditions such as rainfall, nutrients and acceptable growing conditions.
If the climate was buggered, trees and grasses wouldn’t bounce back after they have been devastated by fire and places like Greece and Australia would be having less fire in the summer months.
A healthy environment will always have periodical fires.
