Burning on purpose
Fire has a rather practical and useful place under certain circumstances.
For decades, we have been trained to look at forest fire as a bad thing. And, to a large extent, those messages are good. However, few things are all bad. Fire has a rather practical and useful place under certain circumstances.
Fire is one cause of catastrophic disturbance, although not all fires are “catastrophic”. Other causes in the Lake States include severe winds, insect and disease outbreaks and flooding. This kind of disturbance favors a suite of tree species, forest types, and ecological conditions. Without this kind of disturbance, these elements will decrease in the landscape.
Explicit examples would be tree species such as aspens and paper birch, which are declining. Wildlife examples would be woodcock, golden-winged warblers, meadow-voles, and white-tailed deer. Young forests, created by “catastrophic” disturbance, are critical elements in a healthy forest landscape.
The forester’s solution to providing habitat for these catastrophic disturbance beneficiaries is forest management and timber harvesting. The desired ecological conditions are created without the destructive and random qualities associated with natural catastrophic disturbance. It is not a perfect solution but it works fairly well.
One of the management tools in the forestry kit-bag is burning on purpose, under conditions when the fire can likely be controlled. The use of fire as a management tool is called prescribed burning or controlled burning. Fire provides ecological benefits where timber harvesting, alone, falls a bit short.
Fire will remove some of the forest litter, the fallen leaves and other debris that accumulates on the ground. Removal of litter exposes more soil. There are many plant species whose seeds will benefit from this soil exposure. Not all seeds have the ability to punch through thick litter layers.
Fire can temporarily reduce the density of shrubs, which cast shade on the ground surface. This window of increased light for a few years allows shade-intolerant plant species to grow and reproduce. These ebbs and flows of various plant species affect many species of wildlife, usually a good thing, and often increases diversity across the landscape.
Fire can reduce the risk of certain insects and diseases. For example, there are cone-boring beetles that have a life cycle that requires various height layers of pine. Fire can remove or reduce the understory pine size class, thus keeping the cone-borer populations at bay. Management can then better encourage natural regeneration when the right time comes along, rather than compromising the effective regeneration of a mature stand.
Fire is a phenomenon that certain forest types are adapted to for their survival. Jack pine is the classic example in the Lake States. Most jack pine cones are glued shut. Temperatures of around 120-130 degrees are needed to melt the glue, allowing the cones to open, and then release seed. Historically, fire has been the main supplier of those cone-melting temperatures. Following the fire, the new seedlings find a perfect environment for growth.
These benefits are good reasons to use fire as a management tool. Well-trained and properly equipped teams of specialists implement a prescribed burn to meet a set of management objectives. Usually, a short window of weather conditions occurs in any given year. In some years, the window fails to occur. When conditions are acceptable, the fire teams work their magic on the landscape.
Prescribed burning is not something for the untrained person to try on their property, although it is certainly possible to do so by those who have experience. However, the good windows of opportunity are usually when the state prohibits burning. This is one of a few examples where good private land management may actually be discouraged by state government.
Prescribed burning does, of course, carry risk. A planned burn that erupts into a wildfire is a worst-case scenario. Such an incidence leaves local residents understandably leery of future prescribed burning plans. Bad news spreads . . . well . . . like wildfire. Indeed, there are a few big black eyes in the history of learning how to properly burn a site. There is also the issue of smoke management. Heavy smoke across a busy highway is a safety risk. People with respiratory illnesses may react poorly to the smoke. Fire and smoke will cause the temporary displacement of some wildlife species.
Because of risk and safety issues, prescribed burning can be expensive. Costs for adequate amounts of personnel and equipment add-up quickly. Because the burning windows are usually only a few days, multiple crews are needed to hit as many sites as possible. Public notice is typically short notice, so the communication lines need to be efficient and, hopefully, effective.
Fire is a natural part and healthy element of many forest types and other vegetation types. The loss of fire changes the nature of the landscape in ways that may be undesirable in the long-run. Yet, prescribed fire is controversial and does have associated risk. It will not work everywhere. However, there are not too many forest management practices that do not involve decisions and risks. That is part of what makes natural resource management an interesting proposition. Visit the Michigan State University Extension website for more information about forestry and wildfires.