Colorado Mountain Pine Beetle   Anthony Kelly
  Mar 22, 2007 09:22 PST 

Top view of adult MPB  (actual size, 1/8 to 1/3 inch).

Here are two articles on the mountain pine beetle infestation of lodgepole
pines in Colorado. The beetle is a normal part of the ecosystem there, but
is now having an unusually destructive impact apparently due to above
average temperatures, drought, and simultaneous maturing of even-aged stands
of these pines.,,2037147,00.html

Anthony Kelly

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Re: Colorado Mountain Pine Beetle   symplastless
  Mar 22, 2007 13:18 PST 

Even aged trees seem to be in a predisposition as a whole all at once verses
uneven aged trees seen very much more diverse. When all the trees are even
aged and reach predisposition, an organism can come in and appear to wipe
them out or better said "move them on to another ecological stage" all at
once. An article on predisposition is here:

John A. Keslick, Jr.
Re: Colorado Mountain Pine Beetle   Lee Frelich
  Mar 22, 2007 15:00 PST 


MPB has also killed about 30 million acres of lodgepole pine in British
Columbia (that's about the size of PA) where the trees are under stress
from much warmer climate in the last few years, and the -40 temperatures to
keep the bug at bay no longer occur.

MPB can also kill jack pine and is now poised to spread across the boreal
forest from Sakkatchewan to Quebec and wipe out the southern edge of the
boreal forest.

Some entomologists I have talked also think it can infest eastern white
pine as well--so you had better hope it does not make its way to the range
of white pine.

Re: Colorado Mountain Pine Beetle   Anthony Kelly
  Mar 24, 2007 02:27 PST 


Had the mountain pine beetle already been present in British Columbia as it
was in Colorado, or was it able to expand it's range? Is it already present
in the lower boreal from Saskatchuan to Quebec? In other words is it the
beetle itself that is spreading or just it's ability to wreak destruction?
Or both?

Anthony Kelly
Re: Colorado Mountain Pine Beetle   Lee Frelich
  Mar 24, 2007 07:58 PST 


MPB has long been native in the lodgepole pine forests that were killed in
British Columbia. It was cold enough there to keep the population low, but
not cold enough to eliminate it. It is now expanding its range into the
lowland boreal forests of central North America (it has just been detected
east of the continental divide and is reported to be spreading rapidly in
the last 2-3 years), where previously it was far too cold for the insect to
survive. So, its ability to destroy the forest and its range are both

People often point out that global warming at high latitudes will occur
more during winter than summer and manifest itself more as warmer minimum
temperatures than during the day, and ask why it would be important. Who
cares how cold it gets in the middle of the night in the middle of the
boreal forest? Well, if it doesn't get down to -45 several times each
winter, red maple can displace spruce trees, since red maple is limited by
that minimum temperature, and if it does not get down to -40 several times
each winter, MPB can kill the jack pine in the boreal forest. The result
is that the lack of extreme winter minimum temperatures can destroy the
boreal forest, which is mainly composed of spruce and jack pine, and we are
seeing both of these changes occurring on a massive scale.


Re: Colorado Mountain Pine Beetle   DON BERTOLETTE
  Mar 24, 2007 11:57 PST 

While I was working for the Chugach National Forest in Alaska 1993-95,
Southeast Alaska was just beginning to experience a Spruce Bark Beetle
epidemic...the Forest Entomologist had just come out tying the epidemic to a
string of warm winters which was allowing better conditions for the beetle
to promulgate...Glen Juday was suspecting global warming for a number of
things, but back then, everybody was more speculative.
The SBB went on to decimate Southcentral Alaska's spruces (90-95% at last
reckoning). As a forester back then trying to propose solutions that were
being stymied by environmental organizations, we had no idea of the global
nature of the problem...we may have been able to isolate the SBB at the
beginning, but there was a point where it would have become futile.
Hindsight rules...

Re: Colorado Mountain Pine Beetle
  Mar 25, 2007 06:39 PST 


When I was working in Montana in the early 1970's there was a lot of concern
about the mountain pine beetle especially in the northwestern corner of the
state where there was a massive forest fire in 1910. That single intense,
fire which burned over 3 million acres in three days converted millions of
acres of virgin forest to bare ground with the result being thousands of acres of
lodge pole pine so thick it was difficult to even walk though.   Although
there was a severe outbreak of spruce bud worms that had lasted over a decade at
the time the worry was about what would happen if mountain pine beetles ever
got going in the maturing lodge pole...I think we are now seeing and the big
fires have yet to start.

The 1910 fire on the Montana/Idaho state line was a subject of study for
forestry students at the University of Montana and there are a couple of really
interesting historical facts from the the Pulaski, a very famous
fire fighting tool was named after a fire crew boss (Pulaski) who got over
90 fire fighters to go into an abandoned mine during the worst of the fire so
they wouldn't burn to death.

That particular fire was one of the most famous fire storms in northwestern
US history but it did not result in as many fatalities than the Peshigo fire
in Wisconsin or Minnesota. The forest service had a couple of very detailed
histories of the 1910 fire and I am surprised that there has never been a
movie made about the event. Most easterners have never heard of the 1910   fire
because at the same time one of the worst fires to ever burn in the White
Mountains of NH took place. I have a copy of the book the forest service
published on the fire but I haven't read it for over 30 years. It might still be
available from the Forest Service