Habitat & Conservation  |  11/14/2019

Habitat How-To // Firebreaks Do Double Duty


By Jim Wooley, Pheasants Forever Senior Field Biologist (Emeritus)

A firebreak is a simple thing – just a gap in vegetation that slows or stops a fire’s progress. But a firebreak is critical for managing the rotating, prescribed burns that enhance upland habitat. Fire rejuvenates early successional vegetation and helps suppress woody invasives. Firebreaks prevent fire escapes, provide fast access around a burn to fight fire, and reduce manpower needs for the burn. 

And when the fire’s done, some firebreaks can work a double shift – creating added cover and food for wildlife. 
Natural features such as streams or ditches can serve as firebreaks, as can trails, lanes or roads.  Green winter wheat, rye and cover crops can stop fire. With harvested cropfields, disking edges or laying a wet line helps ensure fire won’t creep across the stubble.
Firebreaks are best installed the previous season or just before burning. Mowed firebreaks are common and effective, but cross-break fire creep is a concern. To help prevent escapes you should: remove cut vegetation with a hay rake; lay a wet line in the break; attend to backfiring; and make sure the firebreak is wide enough. 

So, how wide is wide enough? Wind speed, humidity, topography, and fuel load and height, are all factors that help determine firebreak width. In general, firebreaks should be 3 times wider than expected flame height. If you are burning tall native vegetation you probably want a 50-foot strip at minimum.
Bare soil firebreaks provide the surest protection against fire going places you’d rather it didn’t (like your neighbor’s barn). Disk firebreaks clean, leaving no fuel connections. Disked firebreaks also provide the best opportunity to add wildlife food and cover. Left fallow, these strips grow back to early successional broadleaf forbs, with open understories perfect for pheasant and quail broods. These areas also often provide annual foods such as lespedezas and partridge pea that are available in the seed bank and stimulated by disking.

Options abound to plant disked firebreaks for food and cover. If fall disking firebreaks ahead of spring burning, you could plant a cool season grain like winter wheat for fall forage that also retards fire next season. Or you might plant perennial legumes (examples: ladino and red clovers, alfalfa) to create a 3- to 4-year green-browse food plot that also serves as brood cover for pheasants and quail. This creates a perennial firebreak if managed correctly with mowing. Note: green firebreaks can build up dead plant litter and may burn readily. 

Spring-disked firebreaks can be planted to grain sorghum, millet and sunflowers, a wildlife grain blend, or annual legumes such as crimson and arrowleaf clover after you have burned. This produces a food plot, disked again the following spring to prepare for fire.