Monday, August 17, 2009

Firestorm

As unbelievable as it may sound, the catastrophic fires that continue to consume forests in BC’s Okanagan Valley owe their strength to a tiny insect that’s about the size of a grain of rice. Specifically, the Mountain Pine Beetle (MPB), which has decimated much of BC’s once lush forest. Natural Resources Canada’s Canadian Forest Service (CFS) estimates that 60 percent of the province’s lodgepole pine forests are already dead. If the MPB continues to spread at its current rate, a staggering 80 percent of the province’s most abundant tree species will be killed off by 2012.

The tinder-dry skeletons of these once mighty trees ignite like kindling when exposed to flame. The heat, coupled with firestorms and the subsequent winds, fan the flames and spread the fires at lightning speed through this once lush valley region.

Both the rapid spread of the pine beetle and the devastating fires that are consuming the trees are triggered by the changing climate.

While current attentions are focused on the BC crisis, the CFS predicts that Alberta’s lodgepole pine forests and Canada’s northern boreal forest will meet the same fate.

I had the opportunity to witness the devastation first hand in June, when my husband and I had a chance to visit BC and Alberta. A child of the west, I simply couldn’t believe my eyes at first. From a distance, parts of the Rockies look like they had been shaved by a reckless barber. Entire mountainsides have been denuded of their beautiful forests. What remains are the spindly gray ghosts of trees, silently waiting for the inevitable fires that will consume them.

It is almost inconceivable that all of this destruction is the result one tiny beetle. The beetles bore into the living tissue of the tree (known as the phloem layer), feed on its nutrients and lay eggs in the tree’s vascular system. But cutting off the tree’s food supply, a beetle infestation can kill a tree in two weeks.

Until very recently, the mountain pine beetle served a very worthwhile purpose. By attacking aging and ailing trees, the beetle effectively helped to prune the forest, making way for healthier, younger trees.

A subtle but deadly increase in winter temperatures has tipped this delicate balance. The control of beetle populations had previously been the result of pronounced drops in temperature. According to the CFS, “Whenever there is a large drop in temperature due to an incoming cold air mass, mountain pine beetle larvae die in proportion to the severity of the drop in temperature.”

When the temperature drop occurs is as important as how severe the drop. A temperature of -37 degrees C during the winter months will immediately kill off 50 percent of the population. Temperatures half that severe, i.e. -20 degrees C will have a similar effect in the spring and fall, provided that the preceding temperatures were above freezing. According to the CFS, “the relatively warmer temperature would have caused the larvae to start to lose their natural antifreeze.”

BC researchers indicate that because populations have expanded so dramatically, a kill rate of greater than 97 to 98 percent in a generation is necessary before beetle populations will begin to decline.

It gets worse. Colorado State University researchers estimate that deforestation caused by pine beetle outbreak will release 270 megatonnes of carbon dioxide into the atmosphere by 2020. To put this into perspective, Canada’s total carbon dioxide equivalent emissions in 2005 were 747 megatonnes.

This devastation will not be limited to British Columbia and Alberta. The pine beetle will advance eastward, while the results of climate change will continue to fan the funeral pyres of the trees that they have already destroyed.

The potential impact of these fires could result in catastrophic loss of life far beyond the west. In his online essay, How The 2010 British Columbia Fire Could Kill 100 Million People, writer Hal Licino predicts that conditions may combine to create the perfect firestorm in the very near future, effectively blocking the skies over North America with enough ash and soot to predicate an ecological collapse.

A nuclear winter, much like the one responsible for the extinction of the dinosaurs 65 million years ago, would likely follow. If Licino’s correct, the ensuing frigid temperatures would likely be enough to finally end the tiny pine beetle’s catastrophic path of destruction.


RELATED WEBSITES

For more on the Mountain Pine Beetle, visit the Canadian Forest Service website at cfs.nrcan.gc.ca.

Hal Linico’s chilling essay, How The 2010 British Columbia Fire Could Kill 100 Million People, is available online at hubpages.com.

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