The Effects of Fire Video Now Available

Do you wonder how fire impacts the native plant communities around you? The new video titled “The Effects of Fire” VT-1139, produced by Oklahoma State University Agricultural Communications Services and Natural Resource Ecology and Management extension faculty, will help answer many of your questions.

The first chapter of the video covers the historical importance of fire prior to European man’s westward settlement. The video is then separated into three chapters including grasslands, shrublands and forests. Within each chapter the impacts and response of key plant species to fire within each plant community are examined. For example, in the forest section, impacts of fire on shortleaf pine (Pinus echinata) and Post Oak (Quercus stellata) are shown through a series of clips with 4-year, 3-year, 2-year and annual burning. This not only shows the impact on the trees, but also how the fire affects the understory herbaceous plant community. Throughout the video the effects of fire frequency or how often an area is burned has on the vegetative plant community and structure is shown to the viewer. The video addresses how season of burn also impacts each of the plant communities. Also highlighted within the video are interviews with fire ecologists and specialists describing the importance of fire to these native plant communities. If you are interested in livestock production, wildlife or just the enjoy the land this video will provide an increased awareness of the importance of fire. “The Effects of Fire” video is an important tool for anyone who currently uses fire to manage the land or is thinking about applying fire on their property. The video is closed captioned and has Spanish sub-titles. As an added feature of the video there are 20 pdf fire publications included on the video that cover a range of topics including prescribed burn associations, conducting prescribed fires and fire prescriptions,  and many more. The Effects of Fire video is available for purchase online at:

If you would like to watch two chapters of the video as it was presented on OSU’s Sunup TV in January of 2012 visit the following link:

FEIS (Fire Effects Information System) is easy to use

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 effects 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 easy to 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 tutuorial to get you started!  The website is easy to use and researchers work to update species summaries as often as possible.

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When is the Best Time of Year to Conduct Prescribed Burns?

One of the main questions many land owners and fire managers often ask about prescribed burning is when is the best time of year to burn? This will vary depending upon specific land management goals. Timing will also depend upon when the burn can be accomplished safely and under favorable weather conditions. When planning prescribed burns it is important for fire managers to know and understand how many days are actually available during a specific season or over the entire year. Knowing this will allow fire managers to plan for and execute a predetermined number of burns during a given year. It can also aid in determining in which season or seasons it may be best to conduct their burns.

Limited Number of Burn Days

Most fire managers have several prescribed fires to conduct during a specific burn season, and if an adequate number of days are not available, some burns will not be conducted that year. Burns not conducted are usually postponed until the next year, adding more burns and needed burn days to an already limited schedule the following year. It can also drastically change management plans on that par­ticular burn unit. More often than not, many burn units are not burned regularly or at all because of a limited number of burn days due to restricting burning during a traditional burn season. This can negatively impact resources in numerous ways, along with creating an increased work load and cost on fire managers trying to implement prescribed burns.

Because of the limited number of burn days, a fire manger may try to burn when conditions are marginal. This can result in a prescribed fire that is not as effective as it should be causing manage­ment goals to not be met. On the other hand, safety may be compromised when prescribed burns are performed under marginal or less than desired conditions because of the need to complete all of the planned burns during that traditional time frame. If prescribed fires were conducted year-round, then more days would be available for burning, and the most optimum days for achieving goals and safety could be used.

Weather Variables

Weather has a major impact on prescribed fires and associated fire behavior. Therefore, the number of days available to burn each year is constrained by weather variables such as: temperature, wind speed, and relative humidity. Achieving the prescribed set of weather conditions during a particular time of the year has always been a dilemma faced by fire managers. If the goals of the prescribed burn are not extremely specific and safety concerns are maintained, then a wide range of conditions can be used for temperature, relative humidity, and wind speed. Often, a narrow window of weather parameters is required due to safety issues, policy, and regulation, which will reduce the number of available burn days.

Even if weather conditions can be met, timing of the prescribed burn is often limited to a single season by policy, tradition, or a lack of understanding of fire effects. Again, this limits the number of available days left to conduct prescribed burns. Remember that historically, fires occur throughout North America at any time of the year. Records show that fires set by Native Americans occurred in nearly all months, with a majority in the late summer. Also a majority of the lightning-caused fires in many regions of the United States occur during the growing season. In many areas burn season is late winter to early spring to correspond with green-up for livestock production, which also coincides with highly variable and changing weather conditions. However,  conditions during the later winter can be favorable for wildfires which will further limit to the number of available burn days.

Limiting burning to a single season will continue to severely limit the application of prescribed fire in many areas. Also the lack understanding fire affects on native plant communities will also reduce the seasonal opportunities for conducting prescribed burns.

There are several publications and videos available that can assist fire managers to better understand fire prescriptions, fire effects and the best time to burn.

The Best Time of Year to Conduct Prescribed Burns

Fire Effects in Native Plant Communities

Fire Prescriptions for Native Plant Communities

The Impact of Fire on the Landscape SunupTV

Prescribed Burning for Pasture Management SunupTV

How does fire affect woody plants?

Multiple biotic (e.g., plant vigor) and abiotic factors (e.g., climate) interact to affect how woody plants respond to fire. Generally speaking, woody plant response to fire depends on whether the plant is a sprouter or non-sprouter. “Sprouter” is an informal name given to plants that are known to resprout (typically from the base or roots) after being top-killed (by fire or other means), whereas “non-sprouter” characterizes plants that rely on seeds to repopulate after being top-killed. For example, eastern redcedar (Juniperus virginiana) is a nonsprouter while alligator juniper (Juniperus deppeana) is a sprouter. Note fire tolerance can vary within the same genus. See Fire Effects Information System to see how specific species respond to fire. Abiotic factors include fire intensity, timing, and frequency. Frequent fire generally favors herbaceous over woody plants, and can be used to keep woody plants in a suppressed, shrub-like state. For more information see Fire Effects in Native Plant Communities (.pdf).

Should I defer grazing after a fire?

The decision to rest or graze a pasture following fire is not necessarily a trivial question. There are numerous variables and potential interactions to consider (e.g., condition of resources following fire, and potential weather in the months ahead). Generally speaking, plant communities that are adapted to fire are also adapted to grazing following a fire. However, timing, intensity, distribution, and duration of grazing as well as the type of livestock must be considered and adjusted accordingly to meet management objectives. If reseeding is necessary following fire, some deferment may be appropriate until the new plants are established. In some cases, deferment may be necessary to allow woody plants to become established and grow beyond the reach of herbivores.

For information regarding prescribed burning and grazing in the Great Plains see Patch Burning: Integrating Fire and Grazing to Promote Heterogeneity. For information regarding grazing following wildfire in the Great Plains see Management after Wildfire.