Scientists try to determine how much carbon "sinks" into forests |

Scientists try to determine how much carbon "sinks" into forests

Allen Best

Oh, the things you do without fully realizing it. Take those errands to the post office, the grocery store, and that occasional trip to Denver. Driving a sports utility vehicle on these trips? Don’t be embarrassed. Many Coloradans do. But even at the 18 miles per gallon of a Chevy Suburban, which is better than most SUVs, that’s a lot of carbon dioxide spewed into the sky. Figure 5 tons for every 10,000 miles.Where does the carbon dioxide go? Into the atmosphere, what one scientist, Jerry Mahlman, calls “our ultimate garbage dump.” As a species, we add an estimated 7 billion tons of carbon into the atmosphere each year, while up to another 2 billion tons is added as a result of deforestation of such places as Amazonia.And just think: The Chinese are only now getting refrigerators, SUVs and so forth. As Americans, we have especially high-carb diets. With only 4 percent of the population, we directly contribute 25 percent of the carbon into the atmosphere.Yet it’s not quite that simple, either. Carbon dioxide does not necessarily stay in the atmosphere. The carbon can be soaked up by oceans and plants. These are what scientists call carbon sinks.But how much carbon these sinks hold is still unclear. For example, forests both emit and soak up carbon. When they are burning or decaying, they give off carbon. When they are young and growing, they absorb it from the atmosphere.Conventional carbon-measuring equipment works fairly well in flatter areas, like Missouri. But in the West, where forests are found mostly in the mountains, these conventional techniques are inadequate.To help get a better handle on the carbon-uptake from these forests in Colorado, a formerly military cargo plane, a C-130, has been used this summer to fly over the Front Range at altitudes of 1,000 to 3,000 feet. Where the plane once carried Jeeps, its belly is now packed with specialized instruments that measure carbon, methane and other gases.”It’s like a flying laboratory,” explains Dennis Ojima, a research scientist in Fort Collins at the National Research Ecology Laboratory, one of several agencies involved in the experiment.Of special interest to scientists conducting this experiment is the site of the 150,000-acre Hayman Fire southwest of Denver. Most burn areas, says Dave Schimel, a scientist at the National Center for Atmospheric Research in Boulder, are too small too get adequate readings of how a forest absorbs or emits carbon soon after a fire. The Hayman area is large enough.Figuring out where the carbon is going could also be worth money under an international treaty such as the Kyoto Protocol. If a country could prove that its forests suck up carbon, that uptake could be credited against the emissions caused by the burning of fossil fuels.Headline:The high and low of bark beetles and warmingBark beetles epidemics to move up in elevation bandAllen BestSpecial to the DailyWarming temperatures may also cause more frequent epidemics of mountain bark beetles in higher elevations of the mountainous West, where ski areas are mostly located, but fewer epidemics at lower elevations.Jeff Hicke, a research scientist at the Natural Resource Ecology Laboratory at Colorado State University, and entymologist Jesse Logan, of Utah State University, set out to predict how the warmer temperatures of the 21st century will affect populations of mountain bark beetles.Mountain bark beetles attack lodgepole and ponderosa pine, which dominate in Colorado in the elevation band from 7,500 feet to 10,000 feet. The bark beetles have twice reached epidemic proportions in Summit County, the upper Eagle Valley, and Grand County during the past 20 years.Different trees, and different bark beetles, dominate at both higher and lower elevations. However, 95 percent of trees killed in recent years by insects have been lodgepole pine.Hicke’s preliminary results predict that as temperatures rise during the next several decades, the number of epidemics will actually decrease in the lower elevations where lodgepole and ponderosa pine dominate. The temperatures will simply become too warm for the beetles.At around 10,000 feet, the higher end of where lodgepole pine are found, the rising temperatures will actually increase the likelihood of beetle infestations in coming decades. This increased incidence of beetle epidemics, then, will briefly increase the potential for forest fires. The risk will be only temporary, however, as the needles from trees are the fuel necessary to start fires. Within four or five years the needles will have decayed.This puts ski towns more at risk. Most are nestled amid forests with long intervals between burns. Fire risk is likely to rise.Vail Colorado

Support Local Journalism