Fire is indispensable for healthy and productive forests

By Randy Moore
Special to The Sacramento Bee
Published: Friday, Jul. 4, 2014

William Wade Keye focused on the positive impacts of accelerating the pace and scale of forest restoration and pre-fire treatments in his op-ed, (“ Please don’t let our burned-out national forests become a ‘national ashtray, ” Viewpoints, June 4.)

I’d like to elaborate on some recent science about fires, in particular the rise and impact of extreme wildfires.

Our priorities with fire management will always be life, property and natural resources, in that order. However, fire is indispensable to the health and productivity of forests in the Sierra Nevada.

It rejuvenates terrestrial and aquatic systems by restructuring habitat and increasing the availability of light, water and nutrients. Recurring fires also reduce flammable brush and other fuels, and help grow large iconic trees, including sugar pines, yellow pines and California black oak.

Fire is so important in the Sierra Nevada that it can be seen as medicine for ailing forests. However, as with most medicines, too large a dose is harmful. Past fire exclusion and timber harvest practices have resulted in significant changes to the structure and composition of many western coniferous forests, and they are often much denser and less resilient to drought, insects, disease and wildfire.

Wildfires that are unusually large and resistant to control, like the Rim fire in the Stanislaus National Forest, have been described as “mega-fires.” They tend to burn large areas at high intensity, threatening communities and ecological values, and killing large swaths of trees, including old-growth trees that historically survive low-intensity fires.

The resulting patches of dead trees and severely burned soils are larger than those typically experienced in recent centuries. These patches may be so large that it takes long periods for coniferous seeds to return and re-establish the forest. During that time, shrubs may become dominant, and large fires may recur before young trees have grown large enough to survive.

Extreme fire behavior also significantly affects the capacity of forests to provide long-term carbon sequestration. Carbon is released into the atmosphere during fires, impeding the forest’s ability to sequester carbon, an important factor in mitigating the effects of climate change. Barring some management intervention, these wildfires are likely to become more common as the regional climate warms and fuels continue to build.

With so much at stake, the U.S. Forest Service and our many partners must focus on accelerating the pace and scale of our restoration efforts. Restoring the land to a more resilient state in the face of climate change and reducing large-scale disturbances such as mega-fires will help us ensure our forests provide clean air and water, timber products, wildlife habitat and recreation opportunities for generations.

Randy Moore is Pacific Southwest regional forester, U.S. Forest Service.