As I write, the Thomas Fire is roaring through Ventura County, California. This particular forest fire will probably be old news by the time you’re reading this issue, but if another one hasn’t caught by then, it’s only a matter of time—it seems there’s a new huge blaze every other month. Unfortunately, that might be on us. For the better part of the past century, the policy in our nation has been to put out forest ﬁres. In the beginning of the 20th century, this seemed like sound resource policy, but it wasn’t very long before scientists started to realize the folly in it. By then, Smokey Bear was on the scene and it was too late. The country had taken up the call that only they could prevent forest ﬁres. In reality, ﬁre has been part of our landscapes for millennia, caused both by lightning and Native Americans, and many ecosystems have grown to depend on it.
It’s worth noting how we can even know that ﬁre is (or was) common in the ﬁrst place. Have you ever counted the rings of a tree to ﬁgure out its age? There’s a whole branch of science called dendrochronology that takes that principle as its jumping-oﬀ point, but there’s more to glean from tree rings than age. A tree goes through a lot in its life—it could get infested by bugs, suﬀer a drought, and maybe even survive a few ﬁres. Whatever the assault, some sort of signature is usually left on the tree. Forest ﬁres often leave scars on the outermost rings of trees, and this scar remains as the tree ages and adds on new rings around it. Dendrochronologists can study tree rings and ﬁre scars and ﬁgure out the ﬁre history of an area. This isn’t limited to the West; working with oak trees that date back to the 1600s, dendrochronologists have found forest ﬁres to occur as frequently as every three years in some Middle Tennessee forests.
If ﬁre was once common, then it naturally follows that to suppress ﬁre would upset a natural balance, which would likely come with some consequences. Basically, preventing fire now will eventually result in a more intense, uncontrollable fire later. This is because the longer an area goes without burning, the more leaves, twigs, branches, and other sources of fuel will build up on the ground. A landscape that has long been suppressed turns into a powderkeg. These megafires are serious threats to public safety. In addition, they could become so immense that they end up devastating even those ecosystems that are dependent on ﬁre.
The idea that an ecosystem can be dependent on ﬁre is foreign to many people. The forest-ﬁre word association that Smokey made popular gave fire a negative connotation, thereby making it easy to infer that ﬁre must be unnatural. This likely gave birth to the myth that the eastern United States was once a giant, uninterrupted forest. In reality, it’s always been a mosaic of ecosystems, from prairies to forests and everything in between, and a corresponding group of plants and animals rely on each of those ecosystems.
There is an ecological principle called succession that, simply put, is the process of change in structure over time. When left unchecked, succession will eventually result in a forest. However, the process is rarely unchecked. In the past, massive herds of bison may have acted as a moderator of succession. In other cases it might be rapid and intense ﬂooding. These natural checks on an ecosystem are referred to as disturbances. In most cases there’s a combination of disturbances, but ﬁre is a major one across many ecosystems. Without it, succession may go unchecked and the diversity of ecosystems may be engulfed by forest.
In general, ﬁre plays an important role in increasing biodiversity in our ecosystems. However, after a century of ﬁre suppression, it is possible that they can get out of hand like those in California now or in East Tennessee last year. For a few decades now, land managers have begun to recognize the benefits of fire and are increasingly conducting ﬁres in controlled settings. Many of our state agencies now prescribe ﬁre in state-owned lands, including many areas in and around Nashville. Once spring rolls around, try visiting some of these areas to see the role ﬁre plays in keeping these ecosystems unique. You might consider starting at Couchville Cedar Glade or Flat Rock Cedar Glades and Barrens.
"Fire, It's Only Natural" written by Cooper Breeden and published by Native Magazine.
To see more from the January 2018 issue, click here.