Forest fires

A lethal misunderstanding

By Janis McMath, Editor-in-Chief

BC is currently shrouded in a field of smoke from the multiple forest fires in Oregon. The air quality index, which rates the danger of smoke on a scale from 1 to 10, puts the majority of BC at a 10. The smoke is supposed to lift on Tuesday—but only minimally. Seeing such an ominous blanket of smoke probably leaves many Canadians questioning: how well off we are in our country—which has 9 percent of the world’s forests?

GOOD FIRES?

Fire is commonly seen as a phenomenon that serves the simple purpose of destruction. And that is the case sometimes. When a perfect collection of disastrous conditions come together, large uncontrollable forest fires can ravage areas beyond simple repair and devastate communities. But a misunderstood truth about forest fires is this: fire creates new life and improves the biodiversity of forests. In fact, for boreal forests—which cover 552 million hectares of Canada—fires are a necessary part of forest growth. (Here on the West Coast, we experience few fires in our wet, non-boreal forests.)

An essential part of the life cycle of a boreal forest is a fire; this natural occurrence offers a plethora of ecological benefits. Fire is a disease and invasive species killer. Causalities among species adapted to the forest are low—they burrow or flee. But an invasive species may not be adapted to fire and their numbers may drop drastically because of it, improving the health of the forest. And speaking of species well adapted to fire, there are many creatures that depend on the fire to live! For example, the Karner blue caterpillar has a very specific diet that includes a wild lupine. In order for this plant to grow, it needs fire to clear some of the plants hanging above it that are competing with it for sunlight. Fire also releases the needed nutrients in leaves, branches, and other things on the floor of the forest—and exposes mineral soil.

Many forest critters also rely on the biodiversity of the forest, and when fire flattens the landscape, trees that were in the shade of adult trees with no access to sunlight previously finally have the chance to grow. Some trees, like lodgepole and jack pine, have special pinecones that differ from their regular pinecones. When exposed to extreme heat, they open—releasing their seeds. New species of trees and plants have the chance to mature, and animals have more opportunities to find the highly specific trees and plants they need for survival. Biodiversity thrives due to fire—the name for this phenomenon has been coined as “pyrodiversity.”

One of the most important ways that fire helps forests is by getting rid of fuel (e.g., leaves, branches, needles) build up. If these forests are left to overflow with fuel, when a fire does inevitably strike by natural or human means, it could be ruthless and devastating—and the forest could potentially never grow back. Forests have a delicate balance, and at a certain point they are prepared for a fire—but if it passes that point, they lose their ability to be fire resilient. In Canada, we are lucky because deforestation, which is permanent forest destruction, only accounts for very few of our forest fires every year. Of the 2.5 million hectares that forest fires disturb in here in Canada per year on average, only around 0.02 percent is permanent. In 2014, only 34,200 hectares accounted for deforestation. The rest of it can (and should) be regrown easily with time and effort! So overall, it is important to view fire as a natural disturbance that initiates a new cycle for the forest.

UNDERSTANDING HOW FOREST FIRES WORK

Fire needs heat, lots of fuel, and oxygen present. These elements form the “fire triangle,” and as cool as that may sound, these factors can wreak havoc. Other aspects to consider are those in the Canadian Forest Fire Weather Index System (FWI), which uses data about wind speed, topography, temperature, humidity, rain, the moisture of fuel, the moisture of multiple layers of soil, fuel type, and the amount of fuel. Scientists can also use dendrochronology—the study of the rings of dead and alive trees—to understand how frequent and intense fires were in the recent past. Additionally, important data to note is that while a bit more than half of all forest fires in Canada were human caused, most of these were in populated areas where it was easy for firefighters to put it out. They still post a great threat, but 67 percent of land burned in Canada is due to fires caused by lightning—and this is usually due to the fact that many are in areas where humans are not threatened so fire is left to play its natural role.

Many consider looking at how much area has been burned as a proper measure for the devastation of an area, but the research says that how intense a fire is, how devastating it is to the ecosystem, and how patchy the fire was are much more significant factors to consider when trying to determine how bad a forest fire was and how long a scorched area will take to heal. On top of that, another focus needed in understanding how awful forest fires are worldwide is on the parameters of a fire. It is not appropriate to report on multiple forest fires worldwide and say that forest fires are getting worse without highlighting the parameters. When the parameters are narrowed, it can be seen that after a forest fire occurs, things often improve substantially, and fires do not often reoccur. For example, while it may be tempting to view the multiple fires in the Mediterranean (between 1980 to 1990) as examples of forest fires worsening around the globe, to properly understand these flames one must look at the data for the total area burned and the regularity of fires occurring afterwards. In the case of the Mediterranean it is easy to observe the drop in the number of fires and area scorched since the previous fires.

There are three types of forest fires: crown fires crawl all the way up trees and burn until everything is gone; surface fires only burn fuel on the surface and they do not reach deep down into the soil; underground fires are hard to put out and burn mostly in the deep levels of soil and can even survive all winter—only to resurface in spring. The season for forest fires is April to October, but expect most activity from the middle of May to August.

MANAGING FOREST FIRES HEALTHILY

In trying to limit a fire’s fuel, firefighters often clear a swath of trees ahead of the fire so there is nothing to burn. They sometimes set a controlled fire in front of a wildfire to achieve this—the term for this is “backburning.”

This method is a type of a “controlled burn,” which are intentionally set fires that serve a good purpose. For example, they could be set to simulate the natural occurring fires and eliminate the possibility of more destructive fires. This idea of a controlled burn may only be becoming more popular now—seeing how most regions have not changed their harsh fire suppression laws regardless of the understood ramifications of suppression—but it was used in the distant past by native peoples and settlers. Understanding the consequences of fire suppression isn’t something that many have known for long either, and many ranches in the West learnt the hard way. An example of one of the most devastating is Colorado’s Hayman fire in June of 2002. There were multiple factors going right for the fire that year, but the most significant was the build-up of fuel caused by humans intentionally preventing necessary periodic fires from occurring. That fire’s cost was 132 homes, $42 million in suppression efforts, and other immeasurable losses. Understanding and not interfering with the natural processes that keep the forest progressing is equally beneficial for us and the forest—AKA neither of us die.

With this history in mind, the fact that only 0.4 percent of fires in the US are allowed to burn, and the decision that many governments refused to represent the positive ecological benefits of forest fires in fear of sounding inconsistent (our friend Smokey being an example), it is important that we know the beneficial effects now so that we can combat the already prevalent problems of misunderstanding the need for many forest fires.