An uptick in afternoon convection thunderstorms accompanies the summer months. At the same time, we typically start to dry down in April and May, months that are among the driest in the Red Hills.
This annual dry down primes our fuels for fires as we enter the lightning season, a time when fires would have naturally started long before humans came to the region.
Conversion from the longleaf-wiregrass ecosystem that once covered 93 million acres of the Southeast to other land uses and plant communities makes the natural fire regime not always applicable to current habitat types.
Here at Tall Timbers, our habitat is mostly an old field ecosystem, having been under the agricultural plow in the past.
Therefore, our burn season for grasses and shortleaf pines typically starts in March and winds down in May because that is the most effective time to burn old field habitat. This is true for much of the Southeast. We know that fire plays a vital role in maintaining our uplands, but many don’t realize that our wetlands, dotted among the pines and drains along freshwater systems, also need fire.
Fire at the right time creates crucial habitat for amphibians and helps manage against invasive plant and animal species like privet and feral hogs, which have extensive impacts on your land.
Wetlands in this region rely on precipitation from winter cold fronts to fill with water and spur the migration of frogs and salamanders to enter wet pond basins and breed. As the region starts drying in April and May these productive wetlands also start drying down after kick starting a dynamic food web from the wetlands to the uplands.
The end of this dry down overlaps with the lightning season and the now dry wetlands are primed for fire. And this is where we see the timing mismatch with wetland burning in the Red Hills and Albany regions.
The common March-to-May timing of prescribed fire means flames meet wetlands still flush with water, which extinguishes them before the fire’s work is done.
Without fire, wetlands become overgrown
It is common to see wetlands with shrubby vegetation around the edges because the timing of prescribed fire is out of sync with when the wetlands need fire. These shrubby edges continue to grow year after year converting what would be an open and grassy pond into a hardwood thicket.
The water often becomes deoxygenated due to hardwood leaf litter accumulation which changes the water chemistry. The loss of the open canopy shades out grasses and a duff layer of leaves and roots covers the wetland bottom.
Throughout South Georgia and North Florida, we see wetlands in this condition due to the timing or lack of prescribed fire.
Keystone amphibian and invertebrate species typically abandon these overgrown wetlands which also become more attractive to feral hogs. Research data from our Feral Swine Eradication and Control Pilot Program indicates that pigs prefer areas where fire has been excluded, including forested wetlands.
If wetlands have been fire excluded for too long, more intensive wetland restoration is the only way to get them back to their natural structure and function. This includes hardwood removal of the shrubs around and within the pond basin, aquatic herbicide spraying of stumps, and prescribed fire when the ponds are dry.
It is hard to give specific tips on wetland management because it is so nuanced and site specific.
There are many factors at play including the condition of the wetland, the species that still use it and the condition of the surrounding upland. Getting fire into the wetland when it is dry is the most important management action.
Typically, we tell people it’s good to avoid trying to burn wetlands during the December through May amphibian breeding season. But we recognize this is not always possible, and burning wetlands when the moisture conditions allow is most important.
At Tall Timbers we are having success burning the uplands around ponds during our typical burn season, March through May, and then in the summer when the ponds are dry, we return to burn out the pond basin. This approach allows us to avoid creating firebreaks around wetlands. The early season fires burn into the edges of the wetland before the water extinguishes them. Then, our dry season fire burns the interior of the wetland and feathers out to the edges were fuels were consumed by the earlier fire.
Wetland restoration can be a lot of work. However, it is a management action that will make your land less appealing to feral swine, while simultaneously supporting a fascinating group of amphibians and improving the aesthetics of your property.
Typically, the seed bank is still intact so grasses and forbs, amphibians, and insects are quick to recolonize restored wetlands. A variety of birds also visit these sites more, and gamebirds like woodcock and quail love them too.
Wetland management can be a little tricky. If you would like to discuss plans, contact Kim Sash, Tall Timbers’ Biological Monitoring Coordinator. However, if your wetlands are dry, and you can do so safely, now is the time strike the match.