Why do foresters set the forest on fire? The answer is long and complicated – more so than we have space for in this blog. But there are some simple concepts we can discuss, and some resources for further reading.
Bottom line is that Clemson University foresters burn parts of the CU Forest in order to make the forest healthier, more biodiverse, more resistant to catastrophic wildfire, and to foster regeneration of important tree species.
Fire is a natural and normal part of forest ecology throughout the world. It is termed an ecosystem process for the fundamental importance it has in structuring forests and leading to compositional changes underlying patterns of biodiversity. Fire creates openings in the canopy, reduces fuel loads, and fosters some species over others.
History of fire in forests of the South is a much studied topic. Forests in the South have a history of being burned whether being ignited naturally (as by lightning strikes) or by people. People set fires deliberately, to open up forests for hunting and travel, and of course, as throughout history – accidentally. The combination of natural and human-caused fires has left a legacy of forest types throughout the South, which forest managers today attempt to incorporate in their strategies using prescribed fire (controlled burns).
Some areas of the South, whole ecosystems such as the Longleaf pine systems of the Gulf and Atlantic coastal plains were structured and maintained by fire. In other words, the ecosystem would not – could not – persist without frequent, low intensity burns.
In other areas, such as the Piedmont and Appalachian mountains and foothills, fire was probably prevalent, but more patchy and less of a driver of ecosystem structure and function. Cool, moist pockets of forests in Coves burned with less frequency than the xeric ridges and other dry, exposed areas. In the Piedmont and Blue Ridge areas near Clemson, there was likely large, open areas of oak and pine woodland with grassy understories resulting from fire, interspersed with the kind of dense, dark hardwood and mixed pine-oak forests we see today.
There is a strong idea in the literature that Native peoples here actively managed the forest through burning, and there is considerable evidence for this. The would have done this to open up the understory for wildlife habitat, travel, agriculture, and other reasons. Some burning occurred simply because fire escaped from habitations, or campfires on their far-flung travels. Others were deliberately set. European settlers were thought to have adopted the Native practices of using fire to open up woodlands.
By the 20th century the attitude towards fire changed completely, and suppressing fire was now the dominant practice. Think all of the classic, old “Smoky the Bear” ads. Suppressing fire lead to some unintended consequences – whereas more frequent historic fires kept fuel loads (dead and downed wood) low, when fire was suppressed those fuel loads increased leading to – when they happened – more severe and catastrophic wildfire. Also, fire suppression led to dominance of tree species that have a more difficult time surviving burns – and loss of species that are adapted to – and benefit from – frequent fire. So, both structure and composition of forests was influenced by fire suppression – and can be restored through a careful burning program.
The Clemson University Forest has many stands pine species and hardwoods that can be improved, and protected by prescribed fire. Prescribed fire is a highly controlled event, involving numerous staff. By selecting some of these stands for prescribed fire our foresters use a natural ecosystem process to help maintain areas with forest structure conducive to many wildlife species. Fuel loads are reduced thereby reducing impact of future wildfire. Some species – such as grassland birds – have natural habitats restored.
CU Forest staff are also vigilant for wildfires – unplanned burns that can be destructive. Wildfires ignite in various ways and in our part of the state, including lightening but often by carelessness with campfires and the like. More insidiously, sometimes these are set “for fun” as in, arson. If the conditions are ripe for the fire to spread, the result can be destructive for people, property, wildlife, and future forest management. In such cases, the Forest staff works with the SC Forestry Commission and local Fire Departments to control and extinguish wildfires.
We intentionally burn several hundred acres of the Clemson Forest every year. We do so to meet specific management goals. First among these is to maintain a landscape with heterogenous (different) habitat types, giving rise to a diversity of ecosystems and species. Interspersion of grassland and forests creates a patchy landscape that gives rise to higher levels of diversity than any one type alone. The Upper Savannah River basin – where we live – is very high in plant and animal diversity, and our job is to help maintain that.
We also try to restore habitat structure within the stands themselves. In areas that have been clearcut, at first the young pines tend to grow too closely together. Even when planted at the right spacings, natural seedings from neighboring stands give rise to a high density. Pine is then thinned to reduce that density, and then as the trees grow those areas are burned to maintain an open understory.
Regeneration of selected species is another goal of a good burning program. Oak forests are a very important native ecosystem, supplying food for game, nesting habitat for many birds, canopy structure, and habitat for long-lived, shade tolerant tree species. As retired Clemson professor David Van Lear learned from his research in the Forest, without fire, young oaks are outcompeted by fast growing competitors. Fire helps because young oaks put their growth into root systems and can resprout, while their competing species grow upward, and are less resistant.
Finally, burning helps with “forest health”. One benefit is that it reduces the risk of catastrophic fire. When fuels are reduced by frequent, low intensity fire, wildfire has less of a chance of burning so hot that the trees themselves would be destroyed. Another benefit is controlling the spread of disease. For example, infestations by the Southern Pine Beetle – that thrives in dense stands – is reduced.
The Forest staff has begun a rigorous program to map historic burns and keep a database of current and planned fires on the CU Forest Data Hub. This enables a better management regime at the same time that it allows researchers and teachers on campus to plan classes, labs, and projects around the fires. Some are now interested in the various chemical, biological, and social aspects of prescribed burning.
This year we are delighted that 9 different research labs on campus are using the CU Forest burns to further their scientific goals. CU Forest staff keep these researchers in the loop when they are planning burns so the faculty and students can implement their monitoring equipment before, during, and after the fires. Atmospheric, biodiversity, microbial function, soil composition, and other interests are being fed by the fire!
Notices of planned prescribed fire will be posted on the CU Forest Facebook page. However, it is impossible to know exactly when such events will take place. Weather conditions, including wind direction and strength, precipitation, and temperature influence when and where we can safely conduct a prescribed fire.
Forest fire even when well controlled in a highly managed prescribed burn is dangerous and we ask that visitors stay away from the area until it is well extinguished.
Then, come back and watch as life returns. The flush of green will soon return and if you are observant, you will see different species coming back in the years after the fire.
References and Further Reading:
MCSHEA, W.J., HEALY, W.M., DEVERS, P., FEARER, T., KOCH, F.H., STAUFFER, D. and WALDON, J. (2007), Forestry Matters: Decline of Oaks Will Impact Wildlife in Hardwood Forests. The Journal of Wildlife Management, 71: 1717-1728. https://doi.org/10.2193/2006-169
Stambaugh, Michael C., et al. “Clarifying the Role of Fire in the Deciduous Forests of Eastern North America: Reply to Matlack.” Conservation Biology, vol. 29, no. 3, 2015, pp. 942–46. JSTOR, http://www.jstor.org/stable/24483128. Accessed 3 July 2026.
Clemson Researchers Find Prescribed Fire Regenerates Oak Forests – US Forest Service Publication
