Portions of this story appeared originally in the Tall Timbers Quail Management Handbook
Over time, and for several reasons, some managers are burning over a longer window that includes most of April and even early May. Why the shift?
Stretching out the burning season has several benefits that include:
- Maintains more quail cover during the hawk migration and primary nesting season for hawks and owls and thus reduces the mortality on quail at a critical time of year.
- Later burning can cause more mortality on hardwood resprouts thereby reducing the need for mechanical treatment of hardwoods.
- Improves the structure of wiregrass ground cover by promoting flowering and a more upright plant structure.
- Creates later summer brood habitat, especially on richer soils. Additionally on really wet seasonally flooded sites, burning during Feb-April may not be feasible in some parts of the south.
Extends the burn season if a land manager needs the extra days. This is a big reason that parts of Oklahoma and Arkansas have embraced early growing season fire, since March and April are the primary wildfire season.
However, there are risks associated with burning later in the growing season.
If it has been a warm spring with ample rainfall, early “green up” may make burning ground cover in late April or May more difficult and risks not getting complete burns. Burning areas with more oak trees also becomes more difficult once they leaf out and shade the understory.
On the other hand, if conditions become too dry, burn restrictions may be put into place that make getting a permit to burn difficult. It’s also a good time to exercise more caution during burns and mop-up to avoid escapes.
Additionally, burning later in the spring comes with the risk of intersecting with the start of bobwhite quail breeding season and any potential early nesters. It certainly intersects with the primary nesting season for wild turkey in the Southeast.
We recommend a common sense but flexible strategy.
While most of the prescribed fire in the Southeast begins in March after the hunting season, recognize that there are benefits to burning later in the spring.
That said, waiting to burn entire areas until May is probably not a good long-term strategy, especially in old field habitat and oak woodlands.
Each year a manager should balance weather, cover conditions, and strike a balance between getting enough burning done while achieving habitat goals.
There is a great example of a property where the manager used to have to post burn roller chop nearly 1/3 of the acreage annually to control hardwoods regular prescribed fires did not top kill.
By shifting burning into April and even some in May, he was able to increase grasses and reduce the need for mechanical treatments while still maintaining high quail numbers.
Over the long-term, the season of burn has shifted to help maintain the right balance of shrubs, forbs and grasses, using late burning to select for grasses and early burning to select for shrubs and forbs.
Often a manager will use other tools in conjunction with fire to make a rapid change in ground cover.
Post-burn mowing/chopping can be a necessary treatment in ground cover management, particularly on old field lands where there may be 10-25% of the uplands that either didn’t burn (due to fire shadows, lack of fuel, or edge effects) or did not produce the fire intensity necessary to top-kill hardwood shrubs.
In other areas the vegetation may have been top-killed but the structure remains too tall.
It is important to flat mow/chop and possibly use selective herbicides in these areas to set back succession to get sunlight down to the ground, select for grasses to carry subsequent fires.
Post-burn mechanical treatments are also beneficial in that if we time our burning and mechanical treatments we are able to top kill hardwoods twice in the same year, which will ultimately lower height of the hardwood shrubs, and select for grasses if mowed, and forbs if chopped. Be cautious however that mowing in the growing season can favor unwanted bahai grass growth.
A burn in March will produce the first top kill, and if we allow hardwoods to invest energy in resprouting to two feet before we do the post burn treatment, we can top kill them again.
Chopping versus mowing
Both roller drum chopping and mowing are effective mechanical treatments for reducing hardwood resprouts, shrub thickets, and palmetto cover.
Each has a different long-term effect on the vegetation condition.
Chopping results in more hardwood resprouts and selects for forbs and reduces grasses.
Chopping disturbs the soil more, depending on the type of chopper, and can affect the fuel bed more than mowing. Mowing tends to increase grasses and does not result in as much hardwood resprouting. In palmetto shrub cover, the opposite is true.
Mowing does not affect the roots of palmetto and while stature is reduced, the coverage of palmetto remains the same. Chopping palmetto results in reduced coverage of palmetto and tends to increase grass and forbs, especially if followed by a prescribed burn.
