Prescribed fire means not only controlled burns used to meet management objectives, but also includes natural fires ignited by lightning that fall within a "prescription" that are allowed to burn as an ecosystem process. A prescription is a set of conditions that considers the safety of the public and fire staff, weather, and probability of meeting the burn objectives. Natural ignitions are sometimes called "fire-use fires" or Wildland Fire Use For Resource Benefit.
Some parks have areas designated as "Natural Fire Zone" in which natural ignitions are closely monitored but allowed to burn as a natural process without intervention. In some mountainous western parks many lightning-caused fires have been allowed to burn and die naturally each year.In most parks, management ignited prescribed fires are used to manage vegetation instead of lightning-caused fires. Prescribed burns have been ignited to reduce hazardous fuel loads near developed areas, manage landscapes, restore natural woodlands and for research purposes. Before any prescribed or wildland fire use fires are permitted, the park must complete a Fire Management Plan and burn plans. Each planned fire must meet all the conditions identified in a no go checklist before ignition.
In order to restore fire to its natural role in the ecosystem Zion National Park has been conducting a series of prescribed burns in recent years. These planned burns are intended to achieve specific resource management goals and to decrease the risks from wildfire. The burns will only occur if the forecasted weather conditions are favorable and adequate firefighter personnel are available. The public will be notified, as much in advance as possible, when the specific burns will occur. As always, firefighter and public safety are the number one priority when conducting any fire management operation.
The goal of the prescribed fire program in Zion is to use management-ignited prescribed fire, where appropriate, for the restoration of fire-dependent ecosystems and species-specific resource management goals. Prescribed fire projects are to be conducted in a manner consistent with land and resource management plans, public health considerations, and approved prescribed fire plans. The policy of using fire as a tool will help decrease risks to life, property, and resources; prescribed fires will help perpetuate the natural resource values for which Zion National Park was established.
The lack of natural fire in Zion (due mainly to past suppression and other land use practices) has contributed to high fuel loadings, changes in tree stand structure, and reduction in extent of grasslands. Prescribed fire is a treatment to reverse changes brought on by fire exclusion. It should reduce fuel loadings, increase success of remaining Ponderosa pine forests to withstand natural fires, reduce extent of brush lands, rejuvenate aspen stands, thin dense conifer stands, and decrease the risks of catastrophic wildfires.
These prescribed fires are conducted under the guidance of Zion 's Fire Management Plan, and are part of several burns anticipated in the next few years. The park works very closely with other state and federal land management agencies in the planning and management of these fires.
At times, visitors to Zion may be temporarily impacted by smoke from these fires. Smoke on park roadways may be a hazard and scenic visibility may be reduced in certain areas. Visitors may also be impacted by temporary trail closures in the vicinity of the fire. Actions are taken to reduce these smoke impacts, such as the timing of the burn, burning only under favorable weather and fuel conditions. While park officials understand these temporary impacts, it is believed that the long-term benefits of restoring the health of the ecosystem and reducing the risk of future catastrophic wildfires is vital to maintaining the integrity of Zion National Park .