Prescribed fire burning during a drought

News
Jul 12, 2013
by WLJ

Landowners often are unable to carry out their fire program due to periodic droughts. Drought does present several challenges to using prescribed fire such as: lack of fuels, dangerous conditions, and burn bans. However, even during droughts, conditions safe to burn are often present. Further, droughts present some opportunities to meet certain objectives such as reduction of overstory fuels and creating a patchy burn.

One of the primary limiting factors of a drought relative to fire is the lack of fine fuels. Lack of precipitation can lead to a reduction in grass growth in grasslands and leaf production in hardwood forests. These fine fuels are needed to carry fires.

Therefore, fires many be patchy in nature or not carry across the burn unit at all.

Another issue is that droughts are often accompanied by high temperatures and wind speeds which make conducting prescribed fire unsafe. Even when conditions may be safe, burn bans may remain in place for long periods of time during droughts due to perceived risk by policy makers.

Droughts can place stress on plants and animals and, therefore, many landowners are concerned about carrying out a fire that may negatively impact these already stressed plants and animals. The lack of rain following a fire is also a concern as grass and other plants may not respond and allow for extended periods of lack of cover, forage, and erosion potential.

The concerns listed above can also be viewed as opportunities. For instance, patchy burns are sometimes the desired outcome. This is especially true for wildlife management. If only 50 percent of the burn unit is consumed by fire, this may be exactly what the prescription called for. If the manager is attempting to remove overstory forest cover, burning during dry conditions when trees are stressed may be the perfect time to accomplish the objective (assuming you can safely carry out the fire).

When planning a prescribed fire or understanding the results of a wildfire, it is important to define the desired fire effects. Fire effects are defined as: The physical, biological, and ecological impacts of fire on the environment. We categorize effects in to groups, first order and second order.

First order effects are related to the burn itself (effects of combustion) while second order effects are usually seen later and relate to the stress caused by the fire interacting with the environment. Examples of some fire effects might be reduction of undesirable species, increase in species diversity, reduction in canopy cover or number of trees, and increases in cattle weight gains.

Fire affects living things differently and researchers have been working to understand fire effects. You can access this information through a website that provides summaries of fire effects by species, regions, and even ecosystems.

The Fire Effects Information System is a clearinghouse of summarized easyto-use fire effects information. There are links to regional summaries as well as species specific information. They cover fire effects on a wide range of flora (including a special section on invasive species), fauna, soils and air. The species descriptions include basic biology, distributions, as well as information on how the species will respond to fire. Citations are also available resources. There is even a tutorial to get you started! The website is easy to use and researchers work to update species summaries as often as possible; find it at www.feis-crs.org/beta/.

When it comes to prescribed fires and your management goals, always ensure that the fire is carried out under safe conditions that you have a reasonable chance of containing the fire. While burning during extreme conditions may yield desirable outcomes, safety is the first priority. Ensure there is adequate personnel and equipment for the conditions and that the burns are legal at all times.

As weather is always an unknown, it is advisable to hedge and only burn portions of the landscape during droughts. This will ensure that some cover, forage, etc., will remain until favorable weather returns.

Soil erosion is often a concern after a fire during drought as there is little ground cover. Much of this concern is unfounded as root biomass has tremendous soil stability potential. However, on steep slopes and in certain soil textures, extra considerations may be warranted.

A final consideration is that fire frequency is the most important consideration regarding fire effects.

Thus, you should do everything possible to maintain the appropriate fire frequency to meet your objectives.

This will often mean burning under conditions that are not perfect. At times when fire is not possible, remember that you will need to burn those units as soon as conditions allow in order to stay as close to the appropriate fire return interval as feasible. — Extension Service

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