That is just one more piece of evidence Extrafire that you don't know what you are talking about.. The beetles killed the trees because global warming let them survive in a warmer Winter. In the past the cold Winters always killed the beetles. This is just one more thing that global warming is doing to us.
So then why do we have pine trees in the south where the winters never get that cold? They should have been wiped out centuries ago if that's the case.
OK, here's some education for you.
Beetles attack pines by boring into the inner layer of bark (where the sap flows) laying eggs, hatching larvae which then feed on it. Pines defend themselves against beetles by pushing them out with sap (pitch). When pines get old their metabolism slows down and so does their sap flow, making them more vulnerable to beetle attack. When this outbreak started BC had 4 times as many overmature pines as 100 years ago, making the pine forests quite vulnerable. As I said before, we had been fighting them off since the early '70's, primarily by logging infested stands and also by slash and burn of small outbreaks. As the years progressed the trees got older and more vulnerable and the number and size of infestations continually increased. These outbreaks happened all over the province, from south to north-central, east to west in the interior of BC. We were barely managing to keep up.
In October of 1985, temperatures dropped to -35 to -40 in the central interior of BC, before there was much snow cover and before the beetles had completed winterizing themselves. That had the effect of stopping a spruce bark beetle infestation that had been devestating the forests to the east of Prince George, and it hasn't started up again since. But the pine beetles bounced right back the next year and our battle against them continued.
In 1980 BC Forest Service personell noticed a dozen red (infested) trees just inside the boundary of Manning Part in southern BC. They notified the Parks personell who replied that they had millions of trees and since it was a park, they would let nature take its course. The next year there were 10 acres of infested trees and the BCFS again notified the Parks Dept. and received a similar reply. In 1982 there were 350 acres infested and the parks people finally realized they had a problem and the area was logged, the infestation stopped. (I had a part in that one.)
When the current infestation started in Tweedsmuir Park, the government had changed. The NDP had been elected with a lot of help from environmental organizations who had mounted major campaigns against BC logging practices. There was no way they would allow the infestation to be logged, no matter how much the Forest Service personell, industry, loggers, local communities and foresters begged, pleaded, warned. By the time the beetles reached the park boundary there wasn't a hope in hell of stopping them.
The contention that it was due to global warming is without basis. It's true that cold can have a detrimental effect on them, but as I said earlier, in the southern part of BC, it never gets that cold, and the frequency and extent of pine beetle outbreaks is much lower there than in the north-central interior. As well, back in the 1930's temperatures were as warm or warmer than now, and there was no such outbreak at that time.
We may have had a hand in the infestation by the fact that we've been fighting fire in our forests for many decades, a contributing factor in the overabundance of overmature trees. If we had gone into Tweedsmuir and logged out the infested trees, it would only have been a delaying of the inevitable. With the pine stands getting older and older with each passinig decade, and outbreaks becoming more and more frequent, it was just a matter of time before we couldn't contain them. We might have gained 10 years, 30, who knows, but eventually this had to happen. Extreme cold in October is quite rare. Could another such cold snap have stopped them? Possibly, but only for a while, because the underlying problem of too many old trees would still be there. I'm told that the pine beetle has been around as long as we've had pine trees, about 60 million years. There have been much warmer epochs during that time as well as much colder. The pines will be back.
That's all for tonight folks. I'll be back.