A Legacy of FireEnormous trunks reach for the sky, lacy limbs stretch to the sun, grooved bark is sanctuary to tiny creatures in the vast cathedral of Douglas-firs that dominate the forests on this side of the Olympic Peninsula. A tree that grows best on bare mineral soil with loads of sunlight, the Douglas-fir's survival depends on that most fearsome but respected of forces––fire. The eastern Olympics experience large scale natural fires every 300-400 years. Thick bark protects mature trees, so they can survive to produce seeds that repopulate burned areas. Flames burn away organic forest floor debris, giving Douglas-fir seeds access to the soil they need. Fire also kills understory plants that may intercept the young sapling's sunlight.
Along with death for some forest plants, fire brings life for the system as a whole. In a national park, preserving natural processes like fire is an important goal. Without it, the Douglas-firs would leave no heirs and be replaced by shade-tolerant hemlocks, not Douglas-firs. The forest structure would change; the cathedral pillars would crumble.