Why are there so many forest fires in British Columbia (please read on)?

[seriously disabled]

I've never lived in British Columbia but I always thought that British Columbia is supposed to be a cold and mountainous region with plenty of snow during the winter months and plenty of rain during all the seasons of the year (including in the summer months).

 

This makes sense because British Columbia is located in the pacific northwest and the pacific northwest region (which British Columbia is part of) is famous for it's abundance of days with lots and lots of rain.

 

So why are there so many forest fires in British Columbia (Canada) if it's a relatively cool and rainy place?

Edited July 5, 2013 by seriously disabled

[D H]

You are thinking that all of BC looks like Victoria and Vancouver. It doesn't. BC is big and mountainous. Those coast mountains on the west suck all the moisture out of the atmosphere. In addition to being home to the wettest cities and towns in all of Canada, British Columbia is also home to the driest cities and towns in all of Canada except the high arctic. Ashcroft BC gets about 8 inches of rain per year.

[arc]

A long period of cold (below freezing temperatures) can dry out trees as efficiently as a warm summer day. The transitions of fall and spring can be the wetter periods and help prevent fires. A more rainy winter is one of warmer temperatures while some of the really colder winters have less snow, go figure. All it takes is a colder and less rainy winter and spring and you can have a very dry forest.

 

Add to this man has changed the natural balance of the forests, they have in many areas an unnatural quantity of forest floor debris. The fires before human management burned to their own natural limits, consuming debris periodically in fast moving but lower intensity burns. So there may be a combination of several factors that produced this unusual occurrence. An unusually cold and dry period preceding is most likely the cause. Find some records of winter jet streams over the last 10 years or so, I'll bet you will see the arctic cold spending a little more time there than usual. arc

[Essay]

You are thinking that all of BC looks like Victoria and Vancouver. It doesn't. BC is big and mountainous. Those coast mountains on the west suck all the moisture out of the atmosphere. In addition to being home to the wettest cities and towns in all of Canada, British Columbia is also home to the driest cities and towns in all of Canada except the high arctic. Ashcroft BC gets about 8 inches of rain per year.

 

Right! BC extends all the way east to include the Eastern Slope (Front Range) of the Rocky Mountains. We've got Mountain Pine Beetles killing trees like crazy in this area, and it's worse up in the Canadian Rockies. The climate used to be cold enough, on many mountain tops, to keep the beetle from migrating from one valley to another; but recently those mountain tops have been warmer. Even the pika is losing it range, being pushed off the mountain tops by advancing heat.

http://www.sciencedaily.com/releases/2011/04/110420081826.htm

"...the rate at which the climate-sensitive species is moving up mountain slopes has increased 11-fold since the 20th century...."

Now the Pine Beetle can travel more easily between mountain ranges.

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http://www.nps.gov/romo/naturescience/mtn_pine_beetle_background.htm

"Pine Beetle Epidemic From Canada to Mexico: Park Takes Local Actions

Bark beetles are native insects that have shaped the forests of North America for thousands of years. Bark beetles range from Canada to Mexico and can be found at elevations from sea level to 11,000 feet. The effects of bark beetles are especially evident in recent years on Colorado's western slope, including Rocky Mountain National Park...."

"Hard winters with cold temperatures can kill beetle eggs and larvae wintering under a tree's outer bark. Related to general climate warming, average winter temperatures in the Rocky Mountains have been higher than normal over the past ten years. Trees have also been weakened by a prolonged period of low precipitation. The combination of milder temperatures and low precipitation has aided a vast outbreak of beetles."

Mountain pine beetle - Wikipedia, the free encyclopedia

en.wikipedia.org/wiki/Mountain_pine_beetle

The threat of mountain pine beetle to Canada's boreal forest. It may be the largest forest insect blight ever seen in North America. Climate change is said by ...

Pine Bark Beetles Poised for New Attacks on Canada's Boreal Forests

www.scientificamerican.com/article.cfm?id=pine...beetles...canadas...‎

Apr 11, 2013 - After more than a decade, the mountain pine beetle epidemic that surged ... to 2011 to become one of the worst ecological disasters in Canadian history. ... "The rate of expansion surprised virtually all of us," said Allan Carroll, ...

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I've heard it is about 10 times worse up in BC than it is down here in Colorado. Our recent "Black Forest" fire was said to be more severe due to the large number of "beetle kill" trees in the area.

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Edited July 5, 2013 by Essay