Above: Image © Shaun Lowe, iStockPhoto.com

August 1, 2006

Now that summer has kicked into high gear, families across the country are heading off to enjoy the sunshine and warm weather. As you prepare for your annual family camping trip, make sure you've got all the essentials: bathing suit, bug spray, and food. Once the tent is up, you've splashed around in the lake for a bit, and night starts setting in, you'll probably want to build a camp fire...mmmm, roasted marshmallows! But, here's the question: are you allowed to have a fire on your campsite?

The hot, dry conditions of summer in many regions across Canada make this prime time for forest fires. This is why campfires are often banned. If there hasn't been enough rainfall during these hot months, the land becomes dry, dry, dry, which makes for perfect forest fire conditions. A small spark is often enough to set off a blaze in the woods, so you can only imagine what a camp fire might do!

In July alone, forest fires forced the evacuation of approximately 2000 people in both northern Saskatchewan and interior BC. Just last week (July 24-26, 2006), 400 people who had been evacuated from their homes on Galiano Island (British Columbia) were allowed to return, but were warned to remain on evacuation alert should the forest fire come back to life.

But are forest fires always so devastating and dangerous?

The media report on the human impact of forest fires, which can indeed be a safety concern. So, it may come as a surprise that forest fires are also a very necessary and natural phenomenon, providing many ecological benefits.

Did you know? Fires caused by lightning account for approximately 35% of all fires started in Canada, but comprise 85% of the total area burned.

Canada's forest fire season starts in April and continues through September. By the time autumn comes, an average of 25,000 square-km will have burned in almost 10,000 fires. This may sound like an awful lot of destruction, but the majority of the time, Parks Canada won't interfere unless communities are threatened.

Did you know? Forest fires help increase biodiversity by nutrient recycling and the generation of new habitats.

As opposed to logging (i.e., harvesting trees for production of lumber), in large areas of forest that are lost to fires, the burning of wood actually releases stored nutrients such as carbon and nitrogen back into the environment in a form that can be used by other plants. In cool, temperate regions nutrient release by decay of leaves, logs, and needles, known as the 'litter layer', on the forest floor can be slow; forest fires help speed up the process. Combined with an increase in sunlight to the forest floor, these fires provide conditions that are ripe for new growth.

When a forest gets old it is in what ecologists call the 'climax' stage. These dense, mature forests provide an excellent habitat for certain species, but less so for others. After years with no forest fires, huge areas of climax forest can develop, limiting the biodiversity of an area. By allowing forest fires to naturally destroy pockets of forest, we get a landscape that is peppered with vegetation at various stages of growth; this provides a wide range of new habitats for insects, birds, and mammals. An example is the woodpecker: this bird can often be found in forests that have recently had a fire, since it feeds on bark beetles that take up residence in burnt remnants of trees.

Did you know? Fires help limit population densities (of both animals and vegetation), which reduces competition for resources.

In addition to species that can capitalize on the new environment after a burn, some species of plants are actually highly dependent on fire for their continued survival. Fire adaptations have developed in many species, such as the lodgepole and jack pines. These trees have serotinous resin-sealed cones that can only open once the heat from a forest fire melts the resin coating, allowing the seeds to scatter.

Despite the large number of forest fires that occur each year, park managers also sometimes resort to something called a 'prescribed burn'. These fires help restore ecosystems, and are also used as a preventative measure to clear out the build up of debris, thereby reducing the risk of an "out-of-control" fire in the future. Park managers take into consideration the weather, type of vegetation, fire behaviour, and terrain in order to determine when and where these fires can be safely set. Unfortunately, these fires are still very controversial in practice, as trees provide a valuable economic resource and some feel the benefits do not outweigh the risks.

Did you know? The rate at which a fire burns depends on the type of trees and the amount of moisture in the forest.

Like any natural disturbance, forest fires can and do have their disadvantages; the most obvious of these is habitat destruction. If a fire is destructive enough or species are slow to move into and re-populate an area, soil erosion can occur, which can also lead to run-off into nearby waterways. Colonization by invasive species can also be a problem, limiting the survival and competitive ability of local species. However, most species will benefit over the long term and large mammals are rarely trapped.

For up-to-date fire information in Canada, check out the Canadian Wildland Fire Information System where you can monitor the daily hotspots, heat intensity, and other fire activity with satellite images and maps

http://cwfis.cfs.nrcan.gc.ca/en/index_e.php

Amanda Hindle has a degree in Biology with a focus on in Ecology. She is currently working as a technical writer and editor at Health Canada.

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