in Big Bend National Park

Most of us grew up watching Smokey Bear commercials that stressed how destructive fires were to forests and wildlife. Thanks to recent research in fire ecology we are now realizing that many plant and animal species actually thrive when fires regularly burn through their habitat. We also know that in places like Big Bend National Park, fire is a normal part of a healthy natural environment. Based on that understanding, the National Park Service, like most land management agencies, has radically changed its policy on fire management and fire suppression.

Fire in the Chisos Mountains

Preliminary research in the Chisos Mountains conservatively indicates that lightning-caused fires burned through the high woodland forests about once every 70 years. Studies in other mountainous parts of the Southwest suggest that many areas experienced fires as often as every five years.

A regular cycle of fires in the Chisos consumed the buildup of dead wood and brush, killed off diseased and insect-ridden trees, and worked to thin the forest. One result of fire's impact on the ecosystem was the beautiful oak-pinyon forest of the higher reaches of the Chisos.

The oak and pinyon trees offered abundant food (acorns and pine nuts) for wildlife species such as black bears. Grasses that flourished in fire-maintained meadows and beneath open stands of trees provided highly nutritional food for white tail deer. The high density of deer enabled mountain lions to thrive in the mountains.

Impacts of Fire Suppression

The interrelationships between fire, plants, and animals in the Big Bend region began to drastically change in 1934. That year, a Civilian Conservation Corps (CCC) Camp was established in the Chisos Basin. The CCC crew leaders, like nearly everyone else in the country, believed that all fires were bad and had to be immediately suppressed.

The CCC boys did their assigned job well. They vigorously attacked each new fire and put most of them out before they burned more than a few acres. When Big Bend became a national park in 1944, crews of National Park Service firefighters continued the tradition begun by the CCC and courageously fought all fires that started in the park.

The successful suppression of most fires when they were still small had drastic long-term consequences that early park rangers failed to anticipate. Dead vegetation, which once would have burned up in regular, periodic fires, built up to extremely dangerous levels. Overstocked forests were far more susceptible to insects, diseases, and catastrophic fires.

Since dense canopies blocked sunlight from striking the forest floor, few herbs and shrubs survived in the understory. Lack of periodic fires reduced the vigor and quantity of meadow grasses available to deer. Due to slow decomposition, nutrients locked up in dead wood were recycled at a far slower pace than when fires burned through the forest. Due to fire suppression, Big Bend was becoming a very different ecosystem than what it had been prior to the CCC era.

In the early 1990s Big Bend experienced several of the largest fires ever known for the area. Six decades of fire suppression created excessively high fuel levels which made it much more dangerous and expensive to put out new fires.

Big Bend's Fire Management Plan

All these factors caused the National Park Service to review and rewrite Big Bend's Fire Management Plan. The park now manages fire as a critically important natural process that is allowed to resume its original role in crafting and influencing the plant and wildlife communities of the national park. The task is to manage the natural process of fire in ways that avoid negative impacts on resources and do not threaten human life and property.

Any fire started by accident or by natural causes such as lightning is designated a wildland fire. Big Bend averages ten unplanned fires during the prime fire season, March through July. Each wildland fire is intensively monitored by park staff members who decide on a daily basis whether the fire should be put out.

A prescribed fire is any fire intentionally ignited by management to meet specific objectives such as reduction of flammable materials around developed areas. Each of these fires has a written prescription, a detailed plan on the type of weather, staffing, and other conditions which must be met before the fire can be set. If conditions change and the fire is no longer within prescription, it will be immediately extinguished.

For example, strong winds are common in Big Bend. A prescribed fire is postponed or suppressed if high winds are forecast for the park region. The National Park Service is also concerned about smoke and how it impacts human health and air visibility. Winds sometimes shift direction after a prescribed fire is started. If those winds bring large amounts of smoke to areas of high human use, the fire is put out.

Big Bend's Fire Management Officer sets up a schedule for prescribed burns throughout the park. Such fires were ignited in the Chisos Basin in September 1997 and near the Panther Junction Visitor Center in April 1998. Both fires were about 70 acres in size and were ignited to reduce hazardous fuel loads. Visit those sites to view the reductions in flammable materials and regrowth of vegetation.

The cost of using a prescribed fire to reduce an overload of flammable material can be as low as $48/acre. Putting out a wildfire with excessive amounts of dead wood could easily top $800/acre. Thus, a well-planned program of prescribed burns could cost only 1/16th the price of traditional firefighting.

In some sections of the park we may apply prescribed fire as a tool to eliminate or reduce exotic species such as tamarisk and buffel grass and to encourage native species like mesquite trees and desert grasses. Fire-adapted native plants germinate or sprout immediately after a fire and may replace exotic vegetation. For example, the roots of mesquite are rarely killed in a fire. Even if the entire above-ground portion of the tree is consumed by flames the plant can sent new shoots up from the surviving roots.

Restoring Fire in Big Bend

We will always have fires in Big Bend. We have learned that our original policy of total fire suppression not only made drastic changes in the local ecosystem, it also led to a hazardous buildup of dead wood and brush.

The new policies and attitudes towards fire management will restore and reinvigorate Big Bend's plant and animal communities to more natural conditions. Proper fire management will also enable us to more easily contain future fires that threaten human life, property, and precious resources.