Mountain pine beetle and fire in our forests
Narrator: Every summer for the last few years, large numbers of wildfires have destroyed hectares and hectares of trees and threatened forest communities.
Judi Beck: On average British Columbia has about 2000 wildfires per year. That number can vary considerably from fire season to fire season. We’ve had as few as in the nine hundreds and as many as 4500. So there is a lot of variability in that number. About 50% of those fires are caused by people and the other 50% are caused by lightning.
Narrator: Humans have not only caused some of these wildfires but by continuing to promote fire prevention in the forest, humans have actually contributed to an increase in forest fires. If that sounds somewhat strange, stay tuned to find out about the role that fire plays in the forest and how forest management strategies like prescribed burning help to return forest ecosystems to a state of balance and health.
Bill Fisher: We’ve learned over the last 100 years that we’ve spent the first probably 80 years whether it was with Parks Canada or with Provincial Forest Agencies, always putting out fires. Fighting fires whenever they came on to the landscape. Through more recent research we’ve learned how important fires are to renewing the forest.
Narrator: While fire is nature’s way of thinning the forest and promoting biodiversity, the economic and socio-cultural impacts of wildfires are devastating. Loss of valuable timber not only impacts the forest industry, it impacts many other sectors such as tourism, wood markets and jobs. Due to successful fire suppression, trees in the forest have multiplied, filling open spaces and overtaking grasslands. Species such as the lodgepole pine that rely on fire to prevent crowding have increased throughout western Canada. As the pine trees age, they become weaker and more susceptible to drought, disease and insects. One particular insect that is causing havoc across the western Canadian forest is the mountain pine beetle. Native to the pine forest, this rice-sized beetle actually helps forest renewal by thinning out aging pine forests. Due to climate change and rising temperatures as well as unhealthy forest conditions and fire suppression, the mountain pine beetle population has exploded.
Bob Clark: Our best scientists, both federal and provincial, tell us that we can expect to lose 80% of the mature pine in British Columbia by the year 2014.
Allan Carroll: So the question is how can something so small kill an organism so big? And especially given that this organism here, this tree is capable of producing a whole bunch of toxic resin when it’s actually attacked. And that is the beetle carries with it spores of a blue stained fungus and what it does as it's boring through the bark of the tree, it inoculates at the point of penetration these spores and the spores grow very quickly and what they do is actually shut down the resin production by the tree. So the mountain pine beetle is interrupting one of the most important vascular systems of the tree.
Narrator: To add to this dilemma, the pine beetle epidemic has another consequence. Trees killed by the mountain pine beetle create huge fuel reservoirs just waiting for ignition. Throw in climate change and hot, dry summers and you have a recipe for wildfire. Unfortunately, we can't simply let nature take its course in the forest, since wildfires pose unacceptable risks to public safety. Everyone involved, government, non-government, industry and the public must be open to new ways of restoring forest health. Strategies such as letting fires burn, thinning forests, planting new species and in many cases, fighting fire with fire or prescribed burning are being implemented.
Cliff White: Well prescribed burning is probably not much different for thousands of years. It’s where people choose the time and the place to light a fire, they have some objectives they want to achieve with that fire. I think it’s one of those things you can develop quite a bit of skill for.
Narrator: Prescribed fires grow better forests, creating natural mosaics and better habitat for wildlife and domestic animals. They lessen the intensity of future wildfires by introducing natural firebreaks and reducing forest fuel loads. Prescribed fires promote native biodiversity, stimulating fire-dependent plants to reproduce. Prescribed fires are part of a sound ecosystem management and restoration plan.