Fire Regime

Changing Perceptions of Fire
Not so long ago, fire was perceived as a harmful force to be eliminated at all costs. Yet, despite improvements in skills and equipment, fires cannot always be stopped, and scientists now know it is not always beneficial to stop them. Nearly every ecosystem depends on fire to maintain its health and existence. Fire speeds the process of decay and recycles valuable nutrients back into the soils. Insect pests and plant diseases are controlled. Fires limit the spread of certain plants while encouraging others to grow, and fires create a diversity of plant communities as burned areas recover at different rates. The variety of plants provide a more complex mix of food and cover for wildlife. This increased complexity in turn leads to a greater diversity of wildlife inhabiting the burned regions and a more stable and disaster-resistant ecosystem.

Today, fire management policies reflect both a commitment to public safety and the understanding that fire is a natural component of ecosystems. Park managers still suppress fires that threaten lives and property; now they also ignite prescribed fires to restore natural conditions to areas where fire has been unnaturally excluded.

Prescribed fire is one of the most important tools used to manage fire today. A scientific prescription for the fire, prepared in advance, describes its objectives, fuels, size, and the precise weather and other environmental conditions under which it will burn. If it moves outside the predetermined areas or conditions suddenly change, the fire may be suppressed.

The purpose of many prescribed fires is to reduce fuels. In areas where fires were routinely suppressed, fuels have built up, creating the potential for a much larger, hotter fire than would naturally occur. Prescribed fires reduce ground fuels without harming larger trees. Fires are also used to restore grasslands and habitat diversity.

Prescribed fires burning under optimum weather conditions are beneficial; wildfires caused by the carelessness of humans generally burn under the worst possible weather conditions and can destroy forests and endanger firefighters.

Relict Systems and Fire
The miracle of the Guadalupes lies in the relict mountaintop forests and riparian woodlands. Along with isolated pockets of vegetation around desert springs, they contain a unique diversity of plants and animals that require special conditions that they themselves help to sustain. The long-term trend in this area is toward further desertification and eventual elimination of such special habitats. Very hot fires like the Pine Fire of 1993 greatly accelerate the process, because perimeters of woodlands are instantly destroyed. As woodlands shrink, their capacity to perpetuate their own critical microclimates is impaired. Moist, shaded core areas essential to new growth are diminished. It has been theorized that only with the onset of a major climate change towards cooler, moister conditions will the woodlands reverse their decline and flourish as they did following the last ice age.

Fire and the Future
We know little about the history and impact of natural fires in the Guadalupe Mountains and even less about the past role of humans as agents of fire here. We can only assume that the present ecosystems are those best suited to this time and place. It is a fact, however, that in the absence of fire, fuels proliferate. As the quantity of fuel increases, the stage is set for fires that are ever more destructive.

Obviously, lightning and irresponsible people will continue to cause fires. We must insure that both natural and human-caused wildfires do not burn with catastrophic intensity; such infernos could destroy relict natural zones that are integral to the Guadalupe ecosystem. Prescribed burns carried out during optimal weather conditions can reduce hazardous fuel accumulations and insure that parklands are returned to a state of equilibrium where neither lightning nor human-caused fires can seriously affect the stability of highly significant communities of life. When this goal is achieved, most fires can be monitored and allowed to burn.

Prescribed Burns at Guadalupe Mountains National Park
The Park has implemented an ambitious prescribed fire plan in an effort to reduce accumulations of fuel and restore vegetation types that have been altered by human activities. Several prescribed burns were carried out during the months of March and April, 1997. Spring burning is advantageous for a number of reasons. The breezy weather carries fire through sparse grassland fuels. In wooded areas, spring fires take place before trees leaf out and birds begin to nest. Fire crews are available to manage prescribed burns in the spring, before the busy summer wildfire season starts.

Prescribed Burns in McKittrick Canyon
McKittrick Canyon is of special concern to park managers. The area is important to biologists because it shelters the largest relict woodland in the park, and is home to many rare plants and animals. It is also the park's most popular hiking area, and is well-known for its striking fall colors display. If the woodland vegetation in McKittrick Canyon were to be destroyed in a hot, catastrophic fire, one of the park's most scenic and scientifically valuable areas would be lost.

We know little about fire frequency and its effects in McKittrick Canyon, but descriptions and paintings from the 1930s show us that the vegetation has changed since that time. Then as now, the woodland canopy consisted of maple, walnut, ash, and the large chinkapin oak. What has changed is the density of the undergrowth; the open, grassy ground cover of sixty years ago has been invaded by a dense tangle of wavy-leaf oak and other shrubby, highly flammable plants. It is this flourishing undergrowth that under extremely dry weather conditions could burn hot enough to engulf and kill the canopy trees.

Park managers began to tackle this problem during the spring of 1997, by burning eighty acres along the canyon floor. The burns went smoothly, and the area greened up nicely in the months following the fire. Selected plots in the canyon will be monitored to study the long term effects of prescribed fires on the vegetation.

Prescribed Burns In The Highcountry
Most recently, prescribed fires have been ignited in the high plateau area known as The Bowl. This area was greatly effected by a wildfire in 1990, which killed many large trees. The "skeletons" of these trees have blown over, creating meadows covered with dead logs. Many other parts of The Bowl have not burned in decades, and contain pockets of dense, highly flammable undergrowth. In dry seasons, these small, spindly trees dry out much more quickly than the forest above them; a fire burning in this kind of heavy undergrowth can grow large enough to jump into the crowns of the forest overhead, setting the stage for a catastrophic fire. The objective of the three recent prescribed fires in The Bowl was to reduce both types of fuel accumulations.

The park's most recent prescribed fire burned 550 acres on Frijole Ridge on November 19 through 22 of 1999. Fall and winter fires burn with less intensity than summer fires; cooler temperatures and longer nights make them easier to manage. Although strong winds on November 21 caused the fire to burn 60 acres outside of the prescribed area, the fire stayed on the ground, burning in grass, shrubs, and dead wood, and did not kill large trees.

Fire management will continue to be a "hot" issue in the park with additional prescribed fires planned for The Bowl as well as other areas in the park.