Massive fires in 2002 brought forest changes
Durango Herald, May 10, 2007
Allison Pease, Executive Director

Five years ago, a spark ignited the dry timbers of Missionary Ridge north of Durango. The spark grew into a storm, one that touched our communities across every imaginable level.

The 2002 fires were preceded by a severe regional winter drought. By June, snowpack in Southwest Colorado had dropped to 20 percent of normal, and some experts said that the moisture in live trees was less than that in dead ones.

In the five years since, I've returned to the trails of the San Juan Mountains. Each time, I've discovered a changing landscape. Dead trees laying across trails, others cut through by volunteers. In other places, trails had been reworked to accommodate drainages continually altered by runoff from rain racing down deeply cut, denuded ravines.

Wildfires craft an ever-changing scene, one of endless beauty, constant surprise and continual reminders of the role of fire in our lives. Wildfires are a part of the ongoing cycle of nature's health, a cycle to which resident plants and animals are well adapted.

Almost immediately after a fire, plant life explodes with regeneration. Fires release nitrogen and other nutrients from woody plants into the soil as mineral-rich ash, making these soils a haven for new plant growth. Farmers and ranchers know this well from their seasonal burning of fields.

Some plants survive with traits well-adapted to fires. The bark of mature ponderosa pines thickens with age, segmenting into plate-like panels. If the tree catches fire, these panels pop off allowing the tree to shed the burning bark. This makes ponderosa pines incredibly resistant to low-intensity fires. Cones of lodgepole pines remain closed for years until experiencing intense heat. Thus, making fire critical to the reproduction of these trees.

The effects to animals are longer since most rely on certain habitats. While fires often destroy habitats, regrowth introduces new ecological landscapes. In fact, ecosystems that have gone without fire for many years are often void of animals and birds that rely on low-lying shrubs and annual grasses.

In mountain forests, this is due to high, broad limbs of mature trees blocking sunlight, effectively reducing species diversity. The same is true of plains, where overcrowding by secondary species limits annual seed production necessary to birds and small mammals.

Fires reintroduce variety into these important ecosystems. Historically, fires burned in piñon-juniper forests every 10 to 30 years, in ponderosa forests every two to 10 years, and in the wet, cold reaches of high spruce-fir forests every 150 years. Across the plains, fires were even more frequent, fulfilling a role of balance in plant and animal diversity.

While fires are frightening, we can only hope that they don't touch us directly. That said, fire is a part of nature, vital to the health of our forests and plains.