As stated in the past, fire is a key element in shaping a forest or grassland. Prairies in the west and south and longleaf savannas have been discussed previously.
Thinning and burning are well-known and critical practices for anyone wanting to manage pinelands for wildlife in general and deer and bobwhite quail in particular. But you may be surprised to learn that thinning and burning can be just as important in upland oak stands.
The idea of burning hardwoods — on purpose! — was unheard of in my college days. Oak savanna management seems to get more discussion among conservation communities in the Midwest, which Aldo Leopold poetically described as the battleground of a 20,000-year war between prairie and forest. But there is archeological and botanical evidence of open woodlands throughout the South before farming and development changed the landscape. We have seventeenth century accounts of savannas and open plains in the upland Carolinas, eighteenth century records of bison in Piedmont Georgia, and reports of hilly grasslands with scattered pines and oaks; naturalist William Bartram often alluded to natural strawberry fields that dyed the legs and feet of his horses in his botanical journeys through the southeast in 1776.
It is clear that fire, whether lightning-caused or set by the native population, maintained open woodlands across Georgia. Conversion of land to agriculture or other development altered the landscape before there was any opportunity for photographic evidence of its open character; subsequent abandonment of farmland and fire suppression in the 20th century resulted in the dense forests that many mistake for our land’s “natural,” precolonial state.
| What is a Savanna? What is a Woodland? We define whether an area is a savanna, woodland, or forest based on a measurement of the canopy closure – that is, how much of the sky is obscured by vegetation in the tree canopy when viewed from a single spot. A forest has 80% or more canopy closure, while a woodland has 30-79% canopy closure. A savanna has 10-29% canopy closure; less than 10% canopy is considered a prairie. |
How is this relevant to land managers today? Although the landscape has changed considerably in the intervening time, the habitat requirements of deer, turkey, quail, and other species haven’t.
Just like closed-canopy pine stands, mature hardwood forests lack diverse groundcover. Quail need that mix of native grasses and broadleaved forbs, but so do deer and turkeys – more so than many hunters realize. Managing part of a property as an open woodland or oak savanna will provide valuable cover and forage for deer – not to mention food for pollinators, and insects for poults and chicks. In the Piedmont, where most open lands are either cropfields or hayfields, there just isn’t much year-round native forage.
When creating an oak savanna as with creating a pine savanna, the first step involves cutting unwanted trees. Hilltops and slopes with southern and western exposures are warmer and drier than northern slopes and valleys, making them good candidates for a fire-managed woodland. If the trees are merchantable, you will have to make sure the contractor is aware that you want to leave some of the most valuable trees – oaks, and particularly white oaks. If your tract is too small or the trees are not mature enough to interest timber buyers, you can cut down or girdle unwanted stems yourself until you reach the desired density. An immediate follow-up with the appropriate herbicide will usually be necessary to control stump sprouting and seedling release.
The land is always growing towards a climax forest, so frequent disturbance on the ground is key to renewing new ground cover and keeping tree saplings from filling in the open spaces. As you know, fire is one of a wildlife manager’s most important tools.
“But won’t I burn up my hardwoods?” I hear you say. It is true that some hardwoods – beeches and maples, for example – are not fire-tolerant. Others, such as most oaks and particularly post oak and blackjack oak, have thicker bark and heal quickly from injuries. The shortleaf pine, an upland native, is more fire-resistant than loblolly pine and fits in well with this savanna scenario.
Like any tool, it can produce different results depending on how it is used. Work with a forester to put together a burn plan that will help you achieve your wildlife habitat goals safely.
Additional Resources
Ecology and Management of Oak Woodlands and Savannahs (a pdf)
Fire in Eastern Oak Forests — a Primer (pdf)
Georgia Department of Natural Resources’ page on fire in the many ecoregions of the state.
Towards the Moon or To the Sun 
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