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Anyone who has seen the damage caused by the mountain pine beetle infestation , which has devastated millions of hectares of forest in B.C.,Alberta and parts of the U.S., doesn't need any more evidence ofthe destructive powers of this pest. In B.C. alone, 18.1 million hectares , or about five Vancouver Islands' worth, of pine forest have beenattacked by the beetle since the current epidemic began in 1996.The province expects the infestation to eliminate 80 per cent ofits mature lodgepole pine trees by 2013. Then B.C. premier Gordon Campbell announces a $100-million federalplan to fight the mountain pine beetle infestation in the provincein September 2005. The epidemic has cost the province trees, moneyand jobs. (Chuck Stoody/Canadian Press) The infestation has spread to Alberta and Saskatchewan , and in the western U.S. it has affected more than 17 millionhectares of forest, with the U.S. Forest Service estimating that 100,000 infested trees fall to the ground daily just insouthern Wyoming and northern Colorado. Early on, scientists found that the infestation was contributing toan increase in greenhouse gas emissions as the dead trees release carbon dioxide when they decay, turningthe infested forests from carbon sinks to carbon emitters. But now, new research shows that when the beetles bore into thebark of lodgepole pine trees, they also increase emissions of othertypes of gases that contribute to harmful air pollution in forestedareas. Smog alerts common in national parks Chemists and atmospheric scientists at the Desert Research Institute in Colorado and Southern Illinois University Carbondale have shownthat infested trees release as much as 21 times more volatileorganic compounds, or VOCs, than healthy ones. These VOCs are knownto create harmful particulate matter that makes up part of theatmospheric substance known as haze or smog. Pine trees near Grandby, Colo., show the signature rust color ofthe 'red stage' of a pine beetle attack. Newly attacked trees turnred about one year after an infestation and can stay that way fortwo to four years before turning grey as they lose their needles. (Jen Chase/Colorado State Forest Service/Associated Press) Haze is a mix of gases, particulate matter, water, small amounts ofmetal and other substances that are released into the air as aresult of biological and man-made activities, such as the burningof fossil fuels. Although more familiar in large urban centres, haze is anincreasingly common presence in many forested areas and parksthroughout North America, where it impedes visibility, reduces airquality and can contribute to health problems such as heart andlung diseases. Just this week, The Associated Press reported that Sequoia National Park in California, which is home tomajestic, 3,000-year-old Sequoia redwood trees, has ozone levelscomparable to those in urban areas like Los Angeles. The parkregularly issues smog alerts when poor visibility makes hikingunsafe and warns park staff of the health risks of haze. "What other people have shown is that the haze, if it contains particulate matter , the particulate matter increases cardiovascular symptoms, itleads to asthma, it leads to premature death," said Kara Huff Hartz , assistant professor in the department of chemistry andbiochemistry at Southern Illinois University Carbondale. "The other issue is it's really closely tied into climate changeand how the earth deals with the sun's radiation and how itreflects the light back into space or absorbs it in theatmosphere." Forest devastation hit home Hartz's colleague, Gannet Hallar , asked Hartz to help analyse the gases released from the boreholes that pine beetles make when attacking a tree after shewitnessed first-hand the devastation the beetles had wrought on across-country ski area in Colorado that she had been visiting sincechildhood. "They, unfortunately, had to clear-cut the whole area because allthe trees died, and it was a fire danger for all the cabins," saidHallar, who runs the Storm Peak Laboratory at the Desert Research Institute in Steamboat Springs, Colo. "So,that was just shocking to me, to be honest; that had a big impact." Atmospheric scientist Gannet Hallar points at one of the samplingdevices she and her colleagues used to measure gases released bythe resin that oozes out of trees that have been attacked by pinebeetles. (Courtesy of Gannet Hallar) Hallar, an atmospheric scientist and research professor at theinstitute, knew about a previous study done by Danish researcher Marianne Glasius that had found aseveral-fold increase in emissions of volatile organic compounds,or VOCs, in spruce trees infested with weevils. She wanted to see if the same held for pine beetle-infested treesin the part of Medicine Bow-Routt National Forest in northwesternColorado where her mountain-top atmospheric research facility islocated and which is one of the areas hardest hit by theinfestation. She and her colleagues took samples of the gases coming from theresin that oozes out of the beetle bore holes of damaged tress andcompared them with air samples taken near healthy trees growing atthe same elevation and slope although Hallar said they hadtrouble finding any healthy trees at all in the devastated forest. They found that the concentration of VOCs was significantly highernear the damaged trees and even found evidence of the samecompounds when they took so-called grab samples of air throughoutthe forest. "What's really interesting about the study is we found thecompounds even away from the tree in the background air," saidHallar. "Even above the forest, above the treeline, we still foundthose compounds." VOCs react to form harmful aerosols One compound in particular that drew the researchers' interest was -phellandrene. Its levels were on average 35 times higher nearthe trunk of infested trees than at the trunk of healthy trees "That's the one that was most predominantly found in comparison tothe healthy tree, so [it] almost could be used as a signature,essentially," Hallar said. "What Kara and I are really interested in is whether or not thesecompounds will allow for the formation of more particles in the air and this is a compound that's known to do that." Trunk of a lodgepole pine showing the so-called pitch tubes thatemerge when a pine beetle bores into the tree. (Courtesy of B.C. Ministry of Forests, Lands and Natural ResourceOperations) VOCs released by the infested trees react with oxidants like ozonethat are present in the atmosphere naturally at low levels but areenhanced by human activities. They form a secondary aerosol , a mixture of solid or liquid particles suspended in air thatmakes up one source of atmospheric haze and, in highconcentrations, can be hazardous to human health. Pine trees release some of these volatile organic compoundsnaturally to signal other trees, as a defence mechanism to wardoff predators, or as part of the process of photosynthesis. "If you've been in a pine forest, that piney smell, those are theVOCs that you're smelling," said Hartz. Normally, though, the gases are released at much lowerconcentrations and through the needles, not bark. "This might be one of the reasons why the beetles affect the VOCemissions so much, because normally the emissions don't come fromthe trunk itself, but the beetle actually opens up the trunk andbasically makes a port for those emissions to come out of thetree," Hartz said. Quantifying these emissions, as Hartz and Hallar have done, canhelp scientists better understand how environmental stresses changethe chemistry of the atmosphere and how to improve the models theyuse to make observations about air quality, visibility and climate. "What modelers know is we haven't identified all the sources ofparticulate matter [in the atmosphere], so where this could behelpful to modelers is that they may say, 'Oh, look there's asource of particulate matter that we hadn't considered before.Let's try to include that in our model and see if our observationsmatch better'." Air quality insight could impact policy The study , which was published last week in the journal Environmental Science and Technology and funded by the National Science Foundation , also has policy implications. "In the U.S., you have regulations pertaining to forest service land that require a certain amount ofvisibility that you can see essentially from Point A to Point Bclearly and that your visual experience isn't impacted by airquality," Hallar said. "So, one aspect of this is that thesecompounds would create more haze and thus reduce the air quality." Damaged pines on the boundary between the Quesnel and Prince Georgeforest districts in British Columbia. (Courtesy of B.C. Ministry of Forests, Lands and Natural ResourceOperations) Having more information about what contributes to bad air qualitycould help parks tackle the problem and meet their legalobligations. Hallar and her colleagues hope to incorporate their data into awider model that would apply to pine beetle-infested areas acrossNorth America, although Hallar said she expects to find the sameeffect on VOC emissions in other beetle-infested areas as she didin the Colorado forest. "With confidence, I would say it's happening in B.C.," she said. The researchers who worked on the recent study, who also includedscientists from the University of New Hampshire and AppalachianState University in North Carolina, were also hoping to repeat theoriginal experiment, but the beetle infestation wiped out the pinetrees in Colorado so completely that that won't be possible. "I had a student hike for several days and could not find a healthytree," Hallar said. Instead, she and her colleagues will repeat the experiment in acontrolled environment, where they will be able to observe how theemissions are affected by changes in temperature or humidity. I am an expert from inflatable-amusementpark.com, while we provides the quality product, such as Commercial Bouncy Castles Manufacturer , Inflatable Paintball Bunkers Manufacturer, Commercial Inflatable Slide,and more.
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