The summer of 2003 was the most significant fire season in the history of Glacier National Park. After a normal winter snowpack, precipitation was below average from April through June (66% of normal), but more importantly, July, August, and early September brought almost no precipitation. This came on the heels of the 5th year of drought in northwest Montana. Approximately 136,000 acres burned within the park boundary, which was more than during the previous benchmark fire-year of 1910.
Seldom does everything burn within a fire perimeter. Some areas may be untouched by flames, while adjacent sections burn at a low to moderate severity. These areas will rejuvenate quickly. Other areas are fully engulfed, but will in time provide a vibrant habitat. The result is a dynamic blend of mixed severity burned and unburned forest called the forest mosaic.
Most animals, plants and trees in the Park have evolved with fire. Fire causes rapid change in a forest, creating openings that allow light to reach the forest floor where sun-dependent plants grow. Downed logs and duff on the forest floor are burned to ash, releasing nutrients back into the soil. Many flowering plants such as fireweed and lupine flourish after a fire. Older Ponderosa pine, western larch, and Douglas fir trees have thick bark that insulates the inner living tissue from the heat of a fire. Larch trees have additional fire adaptations. In an intense fire they can lose all their needles to the heat, and then can grow new ones and even replace burned branches along the bole of the tree. These survivors provide seed for reforestation. Other species depend on fire for reproduction. Lodgepole pines drop millions of seeds after a fire and produce vast stands of even aged trees, which can perpetuate a fire cycle on an 80-120 year rotation called a fire regime. Ponderosa pine germinates best on a mineral seedbed, which is provided by fire on a landscape scale.
It is rare for mammals to get caught in a fire. Larger animals are able to move out of the way and most small animals, amphibians and reptiles avoid fire by seeking refuge; i.e., in tunnels in the ground, under large downed logs, or in damp areas. Grazers (such as elk, rodents and ground squirrels) and browsers (such as deer and moose) find new habitat and succulent vegetation where only unpalatable plants grew previously. As these populations flourish, so do predators and scavengers. Birds that nest in cavities take advantage of dead snags and other birds thrive on the increase in insects found in decaying trees. Fire is a major ingredient in the ecology of the Northern Rockies just like the snow, the wind, the rain, and other natural forces. Wildland fire is an essential component of this ecosystem and native plants and animals are well adapted to it.
The diverse stands of forest seen throughout the park are in different stages of regeneration and everyday move one step closer to a time when they will once again be blackened. Glacier National Park has been described as one of the most intact natural ecosystems in the lower 48 states. Fire has played a dominant role in creating the rich biological diversity. Without fire, Glacier Park’s character would be forever altered.