Purpose of burning

The fossil record indicates that "wildfires" are as old as the history of vegetation on Earth. A wealth of evidence points to frequent fire as a feature of the natural environment in this region when first encountered by European settlers. At SNR, we use fire to recreate this feature of the pre-settlement environment. Many plants of this area require fire, either to stimulate growth or germination in the short-term or to maintain appropriate habitat for their long-term survival.

Prescribed burning is an attempt to replicate the natural phenomenon of landscape-scale fire that has occurred for as long as there has been terrestrial vegetation. There are fossilized charcoal remains (for which the only known source is the burning of wood) that have been dated around 300 million years old, long before the first conifers, and much less the flowering plant trees that dominate our most wooded lands today, even existed. Fossil and other remnants of past fires (charcoal and ash) can be found throughout the fossil record, in glacial ice layers and even in the layered muck at the bottom of lakes.

The recent history of fire on our planet and in particular in Missouri has been reconstructed from a variety of sources. These range from the anecdotes and diaries of early settlers from Europe to the scientific documentation of burn-scar patterns of living old-growth trees by Dr. Richard Guyette of the University of Missouri. Many questions remain about details of this history, but it is at least undisputed that fire was an important influence in determining the characteristics of the vegetation of this region up until the last century during which fragmentation of the natural landscape and wild land fire suppression became prevalent.

Paleoecologists have shown that prairies and oak savannas occurred in North America before the arrival of humans 15- or 20- (or whatever number of ) thousand years ago, but that these ecosystems increased greatly in percent coverage and geographic extent after humans arrived and began actually using fire to manage vegetation characteristics in ways that favored the abundance of harvestable plant and animal products.

Prescribed burning has gained wide acceptance among natural area managers across the Midwest, though there is a lot of discussion going on about how best to apply its use and still conserve the full diversity of life. Organisms particularly stressed by fire are fire-sensitive native plant species and the enormous diversity of life that lives in dead plant stems and leaf litter. How can these be conserved while favoring the species that benefit from fire? The arguments are too complex and varied to go into here, beyond saying that while the beneficial effects of fire on certain plant communities are generally accepted, there is much concern about the loss of species in the so-called “detritus food chain”, and various ways to mitigate these losses are being discussed and put into practice. At SNR, the current approach is twofold: a) never burn more than half of all the area we have in fire management during a burn-year and b) let areas within burn units that do not burn in the first pass of the fire remain unburned to provide natural refuges within the burn unit for the sensitive species.

The work of participants in a prescribed burn is quite different from the brush pile burning. There is no lugging of branches and hunks of wood to a raging bonfire. Rather, the work consists primarily of stringing out along and monitoring the edge of the burn area to make sure that the fire does not escape it’s predetermined boundaries. If there are escapes, you must quickly communicate this to the nearest staff person or take immediate action to suppress the escaped flames while calling for help. (The work of prescribed burning has been described as 95% boredom and 5% sheer panic. I would adjust this to contain a significant percentage of smoke inhalation!)

Interested in participating?  Become a volunteer!

Woodland burning

Fire in the woods does kill some smaller trees, and some species not naturally a component of oak-hickory woodland. In a low intensity woodland burn of the sort conducted at SNR, most larger and even some sapling trees survive the fire. The long-term effect of repeated burning of the woods will be a more open woodland, which is a goal of our upland forest restoration. Open woodlands interspersed with grass and wildflowers were the typical vegetation reported on the ridges and upper slopes of this region when first seen by naturalists in the early 1800s. Wide spacing is the healthiest condition for an oak-hickory woodland, Missouri's prime wildlife habitat, as these trees grow best in the better lighting conditions and produce more acorns or nuts (vital wildlife food). A rich array of grasses and wildflowers grows in open woodlands and oak savanna. These plants in turn provide food, nest materials, and other necessities to many large and small animal species which cannot survive in the shadier forest.