Frequently Asked Questions about Patch Burning

Q. How large/small an area will it work on?
A. Currently there have been patch burn studies conducted on units as small as 100 acres to areas over 20,000 acres in size. The results are all similar and have found many positive benefits of PB no matter the size of the unit.

Q. Will patch burning work in more arid parts of the country?
A. Patch burning has been conducted in areas with over 36 inches of annual rainfall to places that receive less than 18 inches of precipitation annually. In drier regions you may want to have a longer fire return interval, which coincides with fuel build-up. Patch burning conducted in these arid sections of the country has shown benefits to vegetation and wildlife, along with no differences on livestock production when compared to traditional management practices of the area. Historically fire occurred in all parts of the US, and if there was fire, grazing also occurred on these sites. Grazing may have not been carried out by large herbivores such as bison, but numerous other grazing animals of smaller size utilized these burned sites.

Q. Will patch burning work on reconstructed prairie or “go back lands”?
A. Yes, patch burning will work on these sites as well. The native vegetation that has been planted or allowed to grow back are the same species that occurred there historically and are very adapted to fire and grazing at the proper stocking rate.

Q. Does patch burning require buffalo to work?
A. Granted bison are the symbolic native ungulate we think of concerning the fire-grazing interaction, but with the proper stocking rate patch burning has been shown to work very well with either stocker cattle or cow/calf enterprises. At this time there has been no work done with other domestic livestock such as goats or sheep. But with the proper stocking rate, these animals should fit very well into the patch burning program.

Q. Can mowing be used effectively to replace grazing? 
A. One of the values of grazing is that it is selective, and both bison and cattle select strongly for grasses. Mowing is nonselective so the effects on vegetation differ from the effects of grazing. If grazing is out of the question, mowing might partially replace the effects of grazing, but it is important to recognize that prairie evolved under the interacting influence of fire and grazing, not fire and mowing.

Q. What season and frequency of burning (fire return interval) is required in patch burning?
A. This depends upon the goals and objectives of the land manager. Burning in two different seasons of the year will create more diversity. Fire frequency depends upon climate and rate of fuel accumulation. One approach is to determine the historic fire return interval for your area and use it as a starting point. If you have large accumulations of fuel and the most recently burned patch is not grazed heavily, increase fire frequency. On the other hand, if fuel loads are light and there is excessive grazing pressure on all of the patches, decrease fire frequency.

Q. What stocking rate of cattle is required for successful application of patch burning?
A. Stocking rate is generally expressed as animal units (cows, steers, etc.)/unit of land area/unit of time, while carrying capacity is the stocking rate that is sustainable over a long period of time. The main question should be, how well does your stocking rate agree with the carrying capacity of the land. Moderate stocking rate fits this description, and moderate stocking results in sufficient fuel to carry a fire.

Q. Will patch burning work on CRP, WRP, and introduced pasture grasses?
A. The full effects of patch burning will not be seen without grazing, but the use of patch burning in set-aside grasslands like CRP and WRP can help suppress woody plant encroachment, assist nutrient cycling, and create some diversity among plants and wildlife. If set-aside grasslands can be grazed, and WRP often allows grazing, patch burning should be effective.  Introduced pastures are designed to be a monoculture, with managers working to keep them uniform with grazing systems, herbicides and fertilizers. So trying to create heterogeneity in a homogenous system is counter intuitive. Still, using patch burning to create structural heterogeneity in these might have some value for some grassland wildlife species including songbirds.

Q. What size should the burn patches be?
A. This depends on your management objectives and logistical constraints. For example, if you were trying to maximize useable space for Northern Bobwhite, 100 acre patches would not be ideal. The home range of quail is normally smaller than this, and since quail require various vegetation structures within their home range, you would want to have smaller patches. Therefore, five 20 acre patches would be preferable. However, this size may not be logistically feasible depending on the landscape, topography, firebreak locations, equipment and personnel available. A compromise might need to be met that will benefit the species managed for, but also be feasible for the land manager. Other species of wildlife will have different optimum patch sizes. If a land manager is trying to promote wildlife diversity, then various patch sizes might be most appropriate, assuming enough land is available.

For more information about Patch Burning visit www.fireecology.okstate.edu 

Other websites:

Department of Natural Resource Ecology and Management www.nrem.okstate.edu

Oklahoma Prescribed Fire Council www.oklahomaprescribedfirecouncil.okstate.edu