Over time, generations of slender, lofty lodgepoles form an umbrella-like canopy that shades the forest floor below.

随着时间的推移，新一代的黑松变得又细又高，伞状的树枝遮蔽了下面的土地。

The fire uses these smaller trees as a step ladder to reach the higher canopy of old lodgepole pines.

火焰通过这些作为阶梯的小树蔓延到更高的黑松树冠。

After the fire, carbon-rich soils and an open sunlit landscape help lodgepole seeds germinate quickly and sprout in abundance.

大火过后，富含碳的土壤和充满的阳光地形有助于黑松种子快速发芽和茁壮成长。

But as the trees' pine cones mature to release their twirling seeds, this signals a problem for the lodgepoles' future.

当成熟的松果在枝头绽放出摇摇欲坠的种子，它们面临着潜在的问题。

Flames ravage the thick understory provided by species like douglas fir, a shade-tolerant tree that's able to thrive under the canopy of lodgepole pines.

火焰燃烧着底层茂密灌木，如花旗松，这是一种能在树荫下茁壮成长的树，它们长在黑松树的树荫下。