- News Home
5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
Trees Exacerbate Forest Smog
16 October 2002 (All day)
KINGS BEACH, CALIFORNIA--Gases released by industry and trees combine in a noxious cocktail that produces damaging ozone in California forests, according to a study presented here on 9 October at the Sierra Science Symposium. The research illustrates the unpredictable consequences of atmospheric pollution.
Ozone is a major component of smog, which damages the lungs. It's even worse for the health of trees such as ponderosa and Jeffrey pines, the dominant species in the Sierra Nevada mountains of California and staples of the timber industry. Some experts believe that ozone might be affecting the majority of the Sierra Nevada. And damage is likely to worsen as the climate becomes warmer, hiking ozone levels in the lower atmosphere. Vehicles, industry, and agriculture are widely blamed for releasing nitrogen oxides and hydrocarbons that waft into the mountains and, in a series of oxidation reactions, produce ozone.
The new research adds a surprising twist: A natural hydrocarbon called isoprene from oak trees in the foothills reacts with the rising, wind-borne nitrogen oxides, producing about half of the ozone in the Sierras. That reaction produces various byproducts. By measuring the concentration of these byproducts, a team led by atmospheric chemist Allen Goldstein and undergraduate Gabrielle Dreyfus of the University of California, Berkeley, determined how much ozone the trees produced. They found that isoprene accounts for 40% to 70% of ozone production in the forest. Such reactions are likely wherever forests are downwind of industrial pollution, says Goldstein, who reported the findings. The study is also published in the October 2002 issue of the Journal of Geophysical Research—Atmospheres.
The research is "of considerable importance," says atmospheric chemist Chris Geron of the Environmental Protection Agency in Research Triangle Park, North Carolina. Natural isoprene bumps forest ozone up to concentrations thought to reduce pine tree growth and endanger the health of people with respiratory problems, he says. But don't go reaching for your chainsaw just yet. "The solution is not to cut down all the trees," Goldstein says, "but to cut back on nitrogen oxide emissions."