Before fire suppression began, the smaller firs and cedars would have been killed by light surface fires while the older trees with thick bark would tend to survive.
(fire suppression; began; ) (the smaller firs and cedars; would have been killed; by light surface fires; T:while the older trees with thick bark would tend to survive; T:Before fire suppression began) (the older trees with thick bark; would tend; to survive) (the older trees with thick bark; to survive; )
fire suppression the smaller firs and cedars the older trees with thick bark the older trees with thick bark
began would have been killed would tend to survive
by light surface fires T:while the older trees with thick bark would tend to survive T:Before fire suppression began
to survive