The thick bark of outgrowth Douglas-fir and ponderosa pine also increases their likelihood of surviving a ground fire, and ground fires (which historically were frequent in many forest types) reduce fuel loads while leaving the overstory of older trees frequently scarred but still intact.
(The thick bark of outgrowth Douglas-fir and ponderosa pine; increases; their likelihood of surviving a ground fire) (older trees; scarred; T:frequently) (ground fires; historically were; frequent; L:in many forest types) (ground fires (which historically were frequent in many forest types; reduce; fuel loads; T:while leaving the overstory of older trees)
The thick bark of outgrowth Douglas-fir and ponderosa pine older trees ground fires ground fires (which historically were frequent in many forest types
increases scarred historically were reduce
their likelihood of surviving a ground fire
T:frequently
frequent L:in many forest types
fuel loads T:while leaving the overstory of older trees