Prescribed Burns

Sustain healthy ecosystems safely

By Tyler Mitchell
Photos: Hurnon-Clinton metroparks

Today, organizations prescribe fires to maintain certain ecosystems—and much like your doctor who prescribes medicine for certain reasons and tells you how to take them—prescribed fire is used to achieve certain goals with a specific set of guidelines for each prescription.

The Huron-Clinton Metroparks in southeast Michigan maintain 25,000 acres of public park land across five counties. The Metroparks Natural Resources Department manages undeveloped land in all 13 Metroparks. The goal is to restore significant elements of natural diversity while balancing ecological stewardship with compatible recreational uses. By carefully utilizing prescribed burns, the Metroparks are able to maintain healthy ecosystems in many of the natural environments that otherwise would shift to non-native or homogenous makeup. The prescribed fire program began in 2002 and currently burns about 250 acres annually. Burn units are generally on a three- to five-year rotation, and staff burn roughly 12 units a year.

Planning For Prescribed Fire
Without the periodic disturbances generated by fire, plant communities begin to shift to areas more densely populated by woody species. Fire-dependent plant species are sharply reduced or lost altogether, and the community loses overall diversity. Increased tree density results in shading out of plants that once thrived in open habitats. These shifts also alter fuels present in the habitat—changing subsequent fire behavior and potentially elevating risk or severity of future fires in these areas. For these and a variety of other reasons, land managers have struggled with large habitats where fire has been suppressed, and have looked to prescribed fire as a tool to restore natural processes and begin to reverse impairments caused by this interruption.

Before planning a prescribed fire, managers should assess the need in each environment as well as goals and outcomes for each prescribed fire. For the Metroparks, a prescribed fire is proposed for one or more of the following reasons:

• Ecological restoration
• Fuel reduction and safety
• Invasive-species management
• Wildlife-habitat restoration.

When assessing the use of prescribed fire in a habitat, managers should consider the capacity of their organization or their contractor to safely and effectively achieve the goals of the fire. Complexities such as varied topography, close proximity of sensitive areas such as schools, hospitals, and houses, fluctuating weather, ease of access for emergency services, and capacity of a burn crew and local authorities to respond to an emergency situation should all be considered.

Once prescribed fire has been identified as the appropriate tool, a land manager develops a burn prescription. This prescription is a document that establishes the goals of the burn and lays out the plan for the day of the burn from beginning to end. It describes the weather conditions required for the burn to be successful and plans several contingencies for shifts in weather or unexpected fire behavior. It also lays out the makeup of the team performing the burn, their qualifications and experience, equipment to be used in the burn, required water capacity of the tanks on-site, and closest source of water available. The prescription identifies the local authorities and municipalities responsible for responding to a potential emergency, such as fire that escapes from the designated habitat and encroaches onto public or private property.

The land manager, or contractor performing the prescribed fire, needs to reach out to local fire authorities and the public in adjacent areas to secure permission and make notice of an upcoming fire. Concerns over potential fire escape, smoke drift, interruption of air traffic, and impacts on air quality in adjacent sensitive areas all need to be addressed with the appropriate authorities prior to the day of the burn. These concerns might be enumerated in the burn prescription, or coordinated outside of it. It is important to identify stakeholders and to begin building relationships with neighbors and other stakeholders and authorities far in advance of any planned fires. There is no substitute for experience when conducting a prescribed fire, but due diligence, communication, and transparency go a long way to ease the tensions neighbors and municipalities will inevitably have whenever there are plans to put fire on the ground. This is particularly true if an organization is conducting a prescribed fire for the first time.

Day Of The Prescribed Fire
The prescription has been written, proper notifications have been given, and the day arrives. The weather has been checked and rechecked, and it has been verified that it matches the required weather from the written prescription. Now, the excitement can safely begin.

Generally, each prescribed fire has a “burn boss” who leads, organizes, and oversees the fire from planning to execution, through mop-up and evaluation. Once the weather conditions are suitable, the burn boss coordinates with local fire departments and staff members that the conditions are right and the burn is a “go.” Once on-site, the crew prepares the borders of the burn unit by defining “burn breaks,” areas where the fire is intended to go out. This is achieved by removing vegetation, blowing away leaves, scraping down to mineral soil with rakes, or otherwise ensuring there is no fuel for the fire in the area. These breaks are often reinforced by “wet lining,” that is, by soaking the area with water prior to ignition.

A burn crew utilizes a specialized device known as a “drip torch,” which often contains a mixture of diesel fuel and regular gasoline with a specialized wick that allows a crew member to carry a flame while walking along the border of the unit and igniting the fire.

Wind is perhaps the largest factor in determining the speed a fire carries across a burn unit. In order to secure all of the burn breaks in a unit, crews ignite on the downwind side, allowing the fire to carry into the wind, where it will burn for a short distance before dying out naturally. This process is known as “back burning” and is generally considered more ecologically friendly, so as the fire progresses slowly, wildlife can get out of the way.

Once the exterior of the unit is secured with burn breaks, a crew may choose to light a “head fire,” which will move from the upwind side, quickly consuming the remaining fuel. This may be necessary if conditions are slightly more humid, or if fuels are more sparse, in order to achieve a good burn. The crew will then begin “mop-up,” which involves putting out any fuels still burning in the interior of the unit and ensuring the perimeter is secure. A crew may stay on-site for several hours after a burn to ensure no fuels are reignited, which can be fairly common as weather changes over the course of the day.

Once a fire regime is reintroduced to a habitat, it is imperative to dedicate resources to that unit and build on successes. One common pitfall of prescribed-fire programs is spreading resources too thin across too many units.

Developing A Prescribed Fire Program
A popular and simple path to developing an internal prescribed-fire program is to seek out a well-established and experienced contractor to aid in the fire’s development and execution. This will aid in easing any concerns of an organization's leadership, as well as those of the public. Even a well-established program is unable to burn each habitat it would like each year, but prioritization and habitat goals should guide decisions year after year. Depending on the region, weather is generally a limiting factor in prescribed fires. There are a small number of viable “burn days” each spring and fall. Because of this, contractors are not in direct competition with internal programs and are able to collaborate to achieve program goals.

The cost of acquiring the tools, equipment, and expertise needed to perform a successful burn can vary depending on the “burn units” an organization is planning to manage. The more complex and remote the site is, the higher threat it presents to adjacent urban areas, and the larger the unit, the higher the cost and level of expertise is needed. For organizations beginning a prescribed-fire program, it is ideal to start with a relatively small, well-defined, low-fuel unit, with easy access to available water and emergency services. This establishes the efficacy of the program and reveals limitations or complications in a lower risk, more stable environment. For instance, an organization might choose to test equipment and capacity by performing a small prescribed burn in the bio-swales of a parking-lot median. Without nearby structures, small units surrounded by concrete provide a low-risk entry point. This approach can used to identify weak points in the program and build the confidence of staff members.

It may also be possible to partner with other organizations. If there are any in your local service region that are coordinating prescribed fires, reach out to them. Ask how they started or even if they’d be willing to partner and assist in management efforts for a mutually beneficial outcome. The Metroparks entered into a MOU (Memorandum of Understanding) with the city of Detroit Parks and Recreation Department in 2019 to assist with land-management projects, including a prescribed fire in a recently restored prairie.

Depending on the region, a number of resources can assist in staff development. The most effective programs are built upon the foundations of the National Wildfire Coordinating Group (NWCG). This group offers standardized, online training courses that prepare staff members for field training. States may or may not require certain qualifications for staff that will perform prescribed fires. It is best to check with your state’s wildland-fire coordinator, a position often housed within a state’s forestry department. That person can assist in identifying qualification levels required or recommended by the state. At the Metroparks, all staff members performing prescribed fires are certified by the NWCG as Firefighter Type 2 crew members.

Regardless of the approach you take to establish a program, it’s most important to remember the planning stages and establish long-term goals of habitat maintenance. A successful prescribed-fire program is focused around goals of proper stewardship and the maintenance of diverse ecosystems for future existence.

Tyler Mitchell is the Chief of Natural Resources and Regulatory Compliance for the Huron-Clinton Metroparks in Michigan. Reach him at tyler.mitchell@metroparks.com.