Small Douglas-fir trees were readily killed by these frequent fires, but the ponderosa pine, with thinker bark and more fire-resistant buds, could sometime survive these fires.
(Small Douglas-fir trees; were readily killed; by these frequent fires) (the ponderosa pine, with thinker bark and more fire-resistant buds; could survive; these fires; T:sometime)
Small Douglas-fir trees the ponderosa pine, with thinker bark and more fire-resistant buds
were readily killed could survive
by these frequent fires
these fires T:sometime