Ravenous pine beetles

2007-08-15

in Canada, Science, The environment, The outdoors

According to an interview with the CBC given by Allan Carroll at Natural Resources Canada, there is not much hope of British Columbia containing the mountain pine beetles (Dendroctonus ponderosae) that have already killed 9.2 million acres of forest. He said that “Our estimates are that by about 2013 to 2015, the beetle will have killed about as much as 80% of the mature pine in the province and I don’t think we can really affect that now.” As the supply of Lodgepole Pine becomes eliminated, the beetles sometimes move on to Spruce and other species. If the beetles begin to target the Jack Pine of the boreal forest, Carroll says that it “could wipe out billions of trees all the way to the East Coast.”

These insects were mentioned here before, in the context of the effect of changing minimum temperatures on species ranges. Apparently, once they have reached their maximum cold tolerance, these beetles can endure temperatures of -40°C. It is significant cold events in the early and late winter – before their chemical defences have fully come on stream – that can lead to “very large amounts of mortality in the [beetle] population.” A few very crisp fall days would do a lot for western Canada’s forests.

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{ 11 comments… read them below or add one }

Vancouverite August 15, 2007 at 1:03 pm

“British Columbia has abundant amounts of mature lodgepole pine forests. These forests would normally be comprised of more tree variety and a more varied composition of tree ages. However, due to many decades of forest fire suppression, the stands are very uniform in age and species resulting in an expansive landscape of prime beetle habitat.”
Source: BC Government

Monocultured sections of replanted forest likely contribute as well.

Vancouverite August 15, 2007 at 1:09 pm
Kate D. August 18, 2007 at 1:40 am

I did a class on advance spatial statistics (GIS) under Dr. Trisalyn Nelson. She and her SPAR Lab are doing some interesting research on the MPB problem that you should check out. My favourite study they did was painting hundred of pine beetles bright pink and releasing them to track their movements and look for any spatial patterns because they only have stand data and not landscape scale ideas of the processes involved with the epidemic. I was also taking a course in entomology at the time and so was heavily immersed in this topic. Not to mention my road trip up north through 100 Mile House, Prince George and also near the Morice forest district was quite astounding.

Milan August 18, 2007 at 1:42 am

Kate,

Front line data is always most appreciated. I am glad to see you are still reading this.

Milan December 17, 2007 at 12:06 am

What is beetle probing?

By Padraic on work

Beetle probing is a seasonal occupation in the forestry industry that is a combination of surveying and pest control. It involves assessing which trees in a given area have been infested by the mountain pine beetle and is part of the ongoing effort to limit the extent of the beetle infestation (and the ecological and economic destruction it brings) in Western Canada.

To start, aircraft fly over pine forests and look for groups of red-needled trees of four or more. They mark GPS points for each of these sites. The job of the beetle prober is go to these sites (finding access via bush roads, pipelines, and walking) and set up a 50, 75 or 100 meter circle, then inspect every pine tree within this circle for signs of the beetle – stripped bark, red needles, and “pitch outs”, where sap has dripped out of the small holes left by beetles as they crawl into the pine bark…

. January 17, 2008 at 2:44 pm

Federal and state forestry officials say that at current rates, the mountain pine beetle will likely kill the majority of Colorado’s large diameter lodgepole pine forests within the next three to five years. The outbreak has become a “top priority” for the Forest Service, in part because of increased risk of forest fires associated with the problem.

Milan March 28, 2008 at 10:13 am

After feast on B.C. forest, pine beetles face famine

IAN BAILEY

March 26, 2008

VANCOUVER — An end is in sight to British Columbia’s mountain pine beetle infestation, largely because the bugs have eaten through most of the trees that had sustained them.

Milan March 28, 2008 at 1:46 pm
Milan April 16, 2008 at 1:07 pm

“With climate change, you need to have adaptive capacity and you don’t have adaptive capacity in sterile monocultures.”

. August 25, 2008 at 9:35 pm

stavrosthewonderchicken’s home is dying

By gen on canada

Canadian expatriate (and Metafilter member) stavrosthewonderchicken has a detailed and depressing look at the impact of the mountain pine beetle in Northern British Columbia, where a perfect storm of “forest fire suppression, clearcutting (and subsequent replanting), [and] global warming” has led to the destruction of over 130,000 square kilometers of forest.

. November 1, 2010 at 1:51 pm

Red foliage however, is one thing you’re not supposed to see a lot of in western North America, any time of year.

In many places in the west–particularly through the central and northern Rocky Mountains and British Columbia–there is now a lot of red foliage, but unfortunately, it’s not just in autumn, and is occurring on non-deciduous species. The proximate causes of this are (1) Dendroctonus spp. (literally, “tree killer”), the most destructive of several destructive bark beetle genera, and (2) tree physiological stress. God’s “inordinate fondness for beetles”*, combined with certain human activities, is now causing some serious problems indeed. Here I’ll try to give background on the issues related to bark beetle outbreaks, working from proximate to ultimate causes, and focusing on the one beetle species currently doing by far the most damage, the mountain pine beetle (MPB), Dendroctonus ponderosae. The MPB is attacking a set of highly important pine species (Pinus spp.) over a very large area of western North America, especially lodgepole pine (Pinus contorta), ponderosa pine (Pinus ponderosa) and whitebark pine (Pinus albicaulis), but also some of the other five needle pines (esp. limber pine). Other species of beetles in the genera Dendroctonus and Ips are also doing some serious damage to these and other species, albeit at smaller spatial scales and/or less intensively, and represent so many variations on the theme illustrated by the MPB.

Much of western North America has elevated tree densities, relative to pre-settlement times, either for all trees, the largest tree classes thereof, or both. This is primarily due to active fire reduction/suppression policies over the last century or more by federal and state land managers, and/or timber harvesting practices. The resulting increased competition, without any increased climate stresses, would by itself increase tree physiological stress and affect beetle outbreak dynamics. The addition of warmer and/or dryer conditions simply magnifies this problem. Similarly, increased climatic stress unaccompanied by increased competition would also favor the beetles. Because natural fire regimes varied widely historically, and are complicated in many places by similar variability in logging practices and intensities, the effect of fire reductions on bark beetle outbreaks varies considerably and involves several issues of spatial and temporal scale variability. This makes the topic both interesting and difficult, and requires good information on past land management practices and forest stand dynamics. That topic however is fodder for another post.

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