The AP gets the bark beetle story right

What a pleasure it is to see a first-rate story on one of the major impacts of human-caused climate change in recent years, “Beetles, wildfire: Double threat in warming world.”  Even the photo caption is spot on:

As far as the eye can see, it’s all infested,” forester Rob Legare said, looking out over the thick woods of the Alsek River valley. The spruce bark beetle, 6 millimeters (.25 inch) long, has devastated the forests of southwest Yukon, aided by warmer summers that speed up its reproductive process and warmer winters that don’t kill off beetle larvae as in the past. Scientists warn that global warming will spur insect infestations and wildfires in the world’s northern forests.

We’ve had a number of bad national stories (from the supposedly liberal media!):

Whereas the local, conservative media got the story right:

Of course, the journal Nature understands the science, as a 2008 article made clear: “Mountain pine beetle and forest carbon feedback to climate change.” So does the Canadian media: “Climate-Driven Pest Devours Canada’s Forests.”

Here’s what the AP reports:

“As far as the eye can see, it’s all infested,” forester Rob Legare said, looking out over the thick woods of the Alsek River valley.

Beetles and fire, twin plagues, are consuming northern forests in what scientists say is a preview of the future, in a century growing warmer, as the land grows drier, trees grow weaker and pests, abetted by milder winters, grow stronger.

Dying, burning forests would then only add to the warming.

It’s here in the sub-Arctic and Arctic “” in Alaska, across Siberia, in northernmost Europe, and in the Yukon and elsewhere in northern Canada “” that Earth’s climate is changing most rapidly. While average temperatures globally rose 0.74 degrees Celsius (1.3 degrees Fahrenheit) in the past century, the far north experienced warming at twice that rate or greater.

In Russia’s frigid east, some average temperatures have risen more than 2 degrees Celsius (3.6 degrees Fahrenheit), with midwinter mercury spiking even higher. And “eight of the last 10 summers have been extreme wildfire seasons in Siberia,” American researcher Amber J. Soja pointed out by telephone from central Siberia.

Along with shrinking the polar ice cap and thawing permafrost, scientists say, the warming of the Arctic threatens to turn boreal forest “” the vast cover of spruce, pine and other conifers blanketing these high latitudes “” into less of a crucial “sink” absorbing carbon dioxide and more of a source, as megatons of that greenhouse gas rise from dead, burning and decaying wood.

American forest ecologist Scott Green worries about a “domino effect.”

“These things may occur simultaneously,” said the researcher from the University of Northern British Columbia. “If the bark beetles kill the trees, you’ll have lots of dead, dry wood that will create a really, really hot fire, and then sometimes you don’t get trees regenerating on the site.”

Dominoes may already be falling in western North America.

From Colorado to Washington state, an unprecedented, years-long epidemic of mountain pine beetle has killed 2.6 million hectares (6.5 million acres) of forest. The insect has struck even more devastatingly to the north, in British Columbia, where clouds of beetles have laid waste to 14 million hectares (35 million acres) “” twice the area of Ireland. It is expected to kill 80 percent of the Canadian province’s lodgepole pines before it’s finished.

Farther north, in the Yukon, the pine beetle isn’t endemic “” yet. Here it’s the spruce bark beetle that has eaten its way through 400,000 hectares (1 million acres) of woodland, and even more in neighboring Alaska, in a 15-year-old epidemic unmatched in its longevity and extent.

“It’s a fingerprint of climate change,” Aynslie Ogden, senior researcher for the Yukon Forest Management Branch, said in Whitehorse, the territorial capital. “The intensity and severity and magnitude of the infestation is outside the normal.”

Hiking through the wild and beetle-ravaged Alsek valley, Legare, the Yukon agency’s forest health expert, explained how the 7.5-millimeter (quarter-inch) insect does its damage.

“Usually the female bores into the tree first, followed by the male, and then they mate and they both excavate a main egg gallery which runs parallel to the wood grain,” he said.

The hatched larvae, just beneath the outer bark, then feed via perpendicular galleries they bore around the tree, cutting off nutrients moving through the phloem and killing the plant. Its needles turn reddish, later gray, and eventually wind topples the dead wood.

Winter spells of minus-40-Celsius (minus-40-Fahrenheit) temperatures once killed off larvae, but those deep freezes now occur less often. And warmer summers enable some beetles to complete their reproductive cycle in one year instead of two, speeding up population growth.

Years of summer drought, meanwhile, weakened the spruces’ ability to extrude sticky pitch, to trap and expel beetles. Because the snow-streaked peaks of the 5,000-meter-high (15,000-foot-high) St. Elias range blocks moisture from the Pacific, a mere 250 millimeters (10 inches) of precipitation falls each year. Even a slight shortfall stresses the trees.

The Yukon has experienced smaller, briefer beetle outbreaks in the past, fed by patches of fallen trees left by road construction. But “what makes this infestation different” is that climate change is a primary cause, said Legare.

As he spoke, smoke from dozens of fires, some nearby in the Yukon, some in distant Alaska, wafted over a landscape already bleak with dead forest.

In an authoritative 2007 assessment, the Intergovernmental Panel on Climate Change (IPCC), the U.N.-sponsored scientific network, cited multiple studies linking the spread of wildfires to warmer, drier conditions.

This June, in the latest such study, as early flames flared in California’s wildfire season, Harvard scientists said the area burned in the U.S. West could increase by 50 percent by the 2050s, even under the best-case warming scenario projected by the IPCC.

In Siberia, “fire has been increasing, and there’s an earlier fire season,” Soja, of the U.S. National Institute of Aerospace, reported from the Sukachev Institute of Forestry in Krasnoyarsk. “For most of Siberia, temperatures are increasing more than in North America.”

In Canada, area burned is double what it was in the 1970s, despite greater firefighting capacity and some recent favorable weather, said Mike Flannigan, a fire researcher for the Canadian Forest Service.

He cited three key reasons: warmer temperatures are drying the forests, lengthening the fire season and generating more lightning, cause of the worst wilderness fires.

Flannigan worries, too, that future fires smoldering through the carbon-heavy peatlands that undergird much of the boreal region would pour unparalleled amounts of carbon dioxide, the main global-warming gas, into the skies, feeding an unstoppable cycle.

“The bottom line is if you get more fire, you get more emissions, which contributes to further warming, which contributes to more fires,” he said in an interview from Ontario.

“The concern is that things may happen more rapidly than we anticipate. Even our most pessimistic scenarios may not be pessimistic enough.”

Back here in smoky gray southwest Yukon, where things are happening, the 1,400 native Champagne-Aishihik people feel it most. The stricken forest’s fallen trees are keeping them from traditional fur-trapping rounds, the streams seem warmer without thick cover overhead, and the fishing is off.

Their oral tradition tells of great change in the past, said the group’s land manager, Graham Boyd. “They’re now wondering what changed to have had this happen.”

What’s changed extends beyond Champagne-Aishihik lands to the rest of the Yukon, where forester Legare in his travels finds other insects “” the northern spruce engraver, the aspen leaf miner, the willow miner “” gaining an upper hand in unusual places in unexpected ways.

“Weird things, unprecedented things are happening,” he said.

Over the top of the world in Siberia, they’re girding for an upsurge in the highly destructive Siberian moth, a caterpillar that devours forests of pine, spruce, fir and larch.

“The moth loves warm and dry, and that’s what’s happening,” said Nadezda M. Tchebakova, Soja’s Siberian research partner. At the same time, she said from Krasnoyarsk, “the frequency and severity of fires should increase.”

As the Yukon warms and burns, its foresters hope for at least an early warning on one immediate threat, the mountain pine beetle. They have set traps at the British Columbia border to alert them if the non-native insect moves northward.

“The Yukon pines probably don’t have natural defenses. They may be uniquely susceptible to this pest,” said ecologist Green. “Then you’ll have the potential for fires in large areas of dead trees. With the needles still on them, they literally explode with fire.”

Of her Yukon woodlands, Ogden said, “It’s the right forest, the right climate type, and we expect the climate to warm. My sense is it” “” the pine beetle “” “is almost inevitable.”

Kudos to the AP.

As Nature noted last year:

Insect outbreaks such as this represent an important mechanism by which climate change may undermine the ability of northern forests to take up and store atmospheric carbon, and such impacts should be accounted for in large-scale modelling analyses….

“The beetle will eat itself out of house and home, and the population will eventually collapse.”

Hmm. “Eat itself out of house and home. Does the bark beetle sound like any other species we know? Finally, the species formerly known as homo sapiens sapiens is no longer alone in its self-destructive quest to destroy its habitat.

He that troubleth his own house shall inherit the wind.”

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8 Responses to The AP gets the bark beetle story right

  1. Mark Shapiro says:

    AP also got the story on record ocean surface temps:

    NOAA: Warmest Global Ocean Surface Temperatures on Record for July

    from RLMiller in dailykos.

  2. ecostew says:

    We were hunting morels on Mt. Adams (WA) a few weeks ago and much of the National Forest area was off limits to hiking. Why – drought stress, bark beetles, and dead trees resulting in extreme fire danger and dangerous falling tree parts.

  3. DrD says:

    I’m not a scientist (and I didn’t even sleep in a Holiday Inn Express last night), but having traveled through the Rockies from Glacier National Park to Mexico this summer, I can attest to the tremendous damage being done. I lived in Wyoming 20 years ago and have no recollection of mountains covered with dead trees. This year’s trip, in part to see the glaciers at GNP before they’re all gone, will include indelible memories of brown forests and a particularly telling sign as I went from Wyoming to Colorado: “Welcome to Colorful Colorado.” Surrounding the sign were dead and dying pines that from a distance reminded me of New England’s colors in the fall. It was colorful, alright, but also very depressing.

  4. Dano says:

    We’ve had much activity and discussion here in Colo about the hillsides that are red or dead. WE also know, as a consequence, that our reservoirs will have less capacity due to siltation. Meaning higher water prices, maybe less irrigation, fewer lawns, etc. There also are recent studies that show the fire risk is increased, but the historical stand-replacing fires are a result of prolonged drought. That is: the droughts are bad enough to burn big, and they are so bad that they will make their own fuel regardless. Whether we are in a new pattern remains to be seen.



  5. kickbass says:

    An important point that is implied in some of these stories but not explicitly stated is that water stress and disease predispose these trees to bark beetle infestations. Saying that the bark beetles are the “cause” of the trees dying is like saying a person with AIDS died of a secondary pneumonia infection. The beetles come in to finish ’em off when they are severely weakened:

    “Healthy trees easily repel beetles with an abundance of resin flooding entrance holes and galleries.”

  6. George Ennis says:

    In Canada this year, as in previous years, we are having devastating fires in British Columbia; related to many of the factors described in the posting. Thousands have had to flee their homes at times when the fires encroached on towns.

  7. Dano says:

    Kicjbass’ assertion about drought is incorrect, as evidenced in the very arty Joe quotes:

    Years of summer drought, meanwhile, weakened the spruces’ ability to extrude sticky pitch, to trap and expel beetles. Because the snow-streaked peaks of the 5,000-meter-high (15,000-foot-high) St. Elias range blocks moisture from the Pacific, a mere 250 millimeters (10 inches) of precipitation falls each year. Even a slight shortfall stresses the trees.

    The MPB is the death blow to the trees, attacking drought-stressed stands. The stands could perhaps recover if moisture became available, but not if the MPB moves in.



  8. Doug says:

    It’s important not to over generalize about the effects of global change on forests. Some will decline (due to fire, insects, drought, temperature dependent increase in respiration) while other forests will thrive (at least for a while, due to longer growing seasons, local increases in water availalability, CO2 enrichment, increased water use efficiency, etc). Those forests that are expected to thrive, such as those with long fire-return intervals along North America’s west Coast, should be carefully conserved so they can continue to grow and sequester carbon.

    Here is a slide show clarifying many misconceptions about forests, logging, and carbon:
    (For full effect click “full” in the lower right.)

    Here is a more detailed foot-noted report on forests, carbon and climate change: