The lower the basal area, the better the habitat for quail
Walking into a forest, the first thing you might notice is either how crowded or open the trees feel. That sense of density is more than just a hunch. Foresters have a way of putting numbers to it, and it’s called basal area.
What is basal area?
Jack Martini, Quail Forever Louisiana state coordinator, described Basal area as the amount of space taken up by tree trunks in a given acre of forest, expressed in square feet per acre.
“There are really two numbers that are impacting your basal area measurement. How many trees are there, and how big are those trees?” Martini said. “If you went through one acre of forest stand and cut every tree off at chest height, basal area is the surface area of the top of that tree stump, and all those stumps added together give you your basal area.”
Martini said the higher the basal area, the more closed the forest canopy. That means less sunlight to reach the ground and stimulate those native grasses, forbs and shrubs, in which quail need to survive.
While there is no golden basal area for quail, according to Martini, the lower the basal area, the better the habitat for quail. Martini said that a basal area above 60 square feet per acre will more than likely not have a thriving quail population.
How do you measure basal area?
Measuring basal area doesn’t need to be complicated, and there are a few tried-and-true methods landowners can use to measure their forest stand.
The most common tools are an angle gauge or a basal area prism. Both are simple, pocket-sized devices that allow you to estimate basal area quickly. Standing at a fixed point, you hold the gauge or prism at eye level and slowly turn in a circle, tallying trees. If the tree appears wider than the angle in your gauge, you count it; if it’s narrower, you don’t. Each tree you count represents 10 square feet of basal area per acre. After tallying, you’ll have a reliable basal area estimate for the stand.
For landowners who don’t have specialized tools, there’s the “thumb and nickel trick,” which utilizes the same method as an angle gauge or prism, but simply uses your thumb or a nickel instead.
How do I manage basal area?
Once you know your forest’s basal area, the next step is management. USDA’s Natural Resource Conservation Service offers a suite of cost-share programs and technical assistance to help landowners meet their goals, whether that’s improving wildlife habitat, growing timber, or both.
Mike Oliver, a retired NRCS forester, recommends three different NRCS practices to manage basal area.
Oliver said forest stand improvement is one of the most effective tools for managing basal area. The practice allows landowners to thin crowded stands through selective cutting or herbicide treatments, reducing competition among trees, opening the canopy and allowing more sunlight to reach the ground, providing better forage and cover for wildlife.
Secondly, Oliver suggests tree/shrub establishment because it allows landowners to set stand density from the start. Choosing the right number of seedlings per acre prevents overcrowding later, reducing the need for heavy thinning as the forest matures. Establishing proper density early also helps ensure stands remain productive for timber and habitat goals.
Lastly, Oliver recommends using prescribed burning as a key tool for long-term management. Prescribed burning helps control encroaching woody vegetation, maintains open conditions, and works in tandem with thinning to sustain desirable basal area levels. Used together, these practices give landowners a framework for balancing forest health with the habitat needs of species like quail, turkey and deer.
For Louisiana landowner Bo Barefield, combining these practices helped him fine-tune his basal area to support his goals.
When a wildfire got loose and burned part of Barefield’s property, the basal area drastically dropped from around 80 to 10-20. Barefield saw firsthand how quickly quail, deer and other wildlife responded to the newly created early successional habitat.
With guidance from private lands biologists, he enrolled in NRCS programs such as EQIP and RCPP and implemented practices like Forest Stand Improvement, using hack-and-squirt and mulching to eliminate unwanted trees, and then prescribed burning to further eliminate woody vegetation and invasive species, while promoting the growth of native plants.
“I was really pleased with the results,” Barefield said. “It knocked down a lot of the understory and mid story, and I started seeing good habitat that just gets more and more beautiful every year.”
Get started by learning more about NRCS programs here. Locating a local PF or QF biologist can be found here.