There is no set standard, but it should be wide enough for the fuels along the boundary of the burn unit. Typically a bareground line 4 to 10 feet wide is sufficient, but narrow cow trails and even mowed lines can be safely used. The width of the firebreak can be offset by reducing the amount of fuel right next to the edge of the burn unit by mowing or shredding to diminish flame heights and fire intensity.
How does fire impact grazing?
Recently burned areas attract grazing animals because of increased forage quality and palatability. Recently burned areas also have fewer external parasites such as flies and ticks which influence habitat use. Grazing animals follow fires; thus, fire can be used to rotate animals across the landscape. However, animals tend to concentrate on these areas until a more recent burned area is available; thus, when a manager wishes to move livestock, fire is a good tool to achieve this.
Historically, was fire important?
Yes. Fire shaped the plant and animal communities that we see presently on the landscape. The important factor is scale, both temporal (time) and spatial (size). Managers should attempt to mimic historic scale of fire to meet the needs of all native species. Even in areas that require very infrequent fire (e.g., 200 years) fire is still important to these systems.
Are fire and grazing interrelated?
Yes, grazing animals preferentially forage on recently burned areas due to the increased palatability of new and re-sprouting vegetation. As a result, fine fuel loads at these sites are reduced, subsequently lowering their near-term burn potential. Conversely and simultaneously, fine fuels on adjacent unburned areas buildup in the absence of concentrated grazing resulting in an increased burn potential over time. The result is an ever-changing mosaic of burned and unburned patches across the landscape driven by the interaction between fire and grazing.