By The Nature Conservancy
From 1815 into the 1840s, the U.S. Government Land Office surveyed the Louisiana Purchase. When surveyors walked gridlines along every square mile, they described in detail the landscape they encountered. At every intersection, they noted the species, size and proximity of “witness trees.” When combined with early explorer and settler accounts, these records paint a clear picture of what Arkansas looked like before extensive European settlement: its woodlands had fewer and larger trees atop grassy floors where wildflowers and other plants supported abundant wildlife, including bison, elk, black bears, songbirds, deer, turkey and quail.
Take a walk in the forests of Arkansas today and you’ll likely find yourself under a dense canopy of smaller, shade-loving trees. What happened?
Prior to European settlement, fire regularly swept through the landscape. In the Ozark Highlands, for example, tree ring studies reveal that fires occurred on average every three to five years. These were fires caused by lightning or by Native Americans, who used fire to improve habitat for wildlife, among other reasons. As a result, most of Arkansas’ ecosystems, with the exception of the wettest bottomland forests, adapted over tens of thousands of years with fire.
In 1911 a Congressional act was passed that allowed the Forest Service to cooperate with states to suppress fires, and a second act in 1924 enhanced funding for these partnerships. In 1942, Disney’s film “Bambi,” which depicted wildfires terrorizing wildlife and destroying forests, was released. In 1944 the Forest Service unveiled Smokey Bear and his “Only you can prevent Forest Fires” campaign, which would become the longest-running public service announcement campaign in U.S. history. Forest fires had been demonized, and over the following decades, our forests grew without the fire that had shaped them for millennia.In the late 1800s and early 1900s, nearly every tree in Arkansas (and throughout much of the South) was cut. Eventually dry debris left over from clear cuts fueled widespread and catastrophic wildfires – a scenario that played out throughout the South and West. The forest managers of the day, led by the U.S. Forest Service, initiated extensive fire suppression programs in an effort to restore forestlands.
Fast forward to 2002. Leading forest managers and researchers from across Arkansas and the nation convened to address the outbreak of the red-oak borer, a native pest that had eaten its way through nearly 1.6 million acres of the state’s oaks. The group was united in its understanding that because the forests were far too dense, they’d become weak and susceptible to drought, disease and pests. Historical records show there once were 38 to 76 trees per acre in the Ozarks’ Boston Mountains. Today there are about 150 trees per acre on average, plus another 300 to 1,000 young stems, all competing for the same, limited nutrients and moisture. To halt the borers, the forests urgently needed to be restored to their pre-settlement form.
Overly dense forests have rippling effects. When sunlight can’t penetrate the canopy, plant growth on the forest floor drastically decreases, which, in turn, affects wildlife diversity and populations. And while periodic, low-intensity fire is a vital and natural part of most Arkansas landscapes, forests that have built up woody debris for decades threaten nearby communities with uncontrollable wildfires, particularly during droughts.
To restore such overgrown forests, they sometimes must first be thinned. After this, controlled burns are used to further reduce tree saplings and woody debris.
At the Piney Ranger District of the Ozark National Forest, a road runs between a forest stand that has been restored and one that has not. The differences between the two are obvious. On the south side, it’s difficult to make way through the dense, dark forest; saplings are tangled with briars and brush. On the ground, thick layers of dead leaves and pine needles prevent much more than poison ivy from growing.
To the north, it’s easy to walk through the open forest. In the spring and summer, its floor is green and splashed with vibrant wildflowers. Here one can catch a glimpse of the forests of the past … and hopefully the future.