It’s pretty basic, after a fire, vegetation is lost and land managers may feel as if all is lost and vegetation will not return without seeding. However, this is rarely the case except with fires that burn at extreme intensities. While the above ground biomass is lost, the below ground biomass is still alive and well. Given time and moisture, pastures that have been disturbed by fire should make a full recovery. What many ask is “How much time do I need to defer grazing after the fire?” The answer depends on a few variables, including: soil moisture prior to the fire, precipitation after the fire, and pre fire rangeland condition. In most cases, plant communities that were in excellent condition prior to the fire should not need a full year to recover given that precipitation is normal or above normal. Those plant communities that were already disturbed, or in poor condition may need up to 2 years to make a full recovery.
Plant communities that exhibited plenty of desirable plants, seeds, root crowns, and rhizomes prior to the wildfire will result in healthy, vigorous plants after the fire. Plant communities that exhibited bare ground, annual weeds, and few perennial plants will result in longer fire recovery periods, and may even need some assistance in that recovery. Weed control and seeding in these situations may help increase the desirable plant community after a fire. In all cases, weed control is very important and can be accomplished through the use of herbicides and even flash grazing. Succession after a fire may see an increase in forb (broad leaf plant) production which can enhance forage nutrition as well as habitat for wildlife. It is important to manage for the plants you want in a system and not those that you do not want.
Types of plants recover at different times after a fire. In a study in Montana on the Northern Mixed-grass Prairie, researchers found that after an August fire, cool season rhizomatous grasses such as Western Wheatgrass, increased that first year, while cool season bunch grasses, such as Needle and Thread, decreased the first year, but made a rapid recover the subsequent years. The found that warm season grass recovery was not dependent on the fire but on the precipitation timing following the fire, just as it is in normal conditions. With respects to livestock grazing, they found that livestock exclusion after fire did not change plant productivity, precipitation was the influencing factor. (L.T. Vermeire, J.L. Crowder & D.B. Wester).
However, fire or not, maintaining good management practices including proper stocking rates, rotational grazing, proper livestock distribution, rangeland monitoring, and weed control are essential to ensure healthy rangelands and a successful post disturbance recovery. Information on these management tools and techniques can be obtained from your local University Extension Office. Educators in these office can also help you with after fire evaluations and give you more localized information on your own unique situation.