News briefs from the frontiers of science

Tree discovery yields clues on ancient forests; why ethanol may not be a pollution solution.

By Peter N. Spotts | Staff writer of The Christian Science Monitor

from the April 19, 2007 edition

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Tree yields clues on ancient forests

Paleontologists combing through a New York State quarry have found the remark­ably well-preserved remains of one of the most ancient trees known. It thrived some 360 to 380 million years ago, stood about 30 feet tall, and sported a feather-duster array of foliage at the top instead of sprouting branches with leaves or needles.

In 2004, a team of US and British scientists uncovered a crown from the tree species, known as Wattieza. A year later, the team uncovered a 28-foot trunk nearby. Wattieza is the oldest known example of a shape that appears repeatedly over the evolutionary history of trees and still appears today in modern palms and tree ferns.

Fossilized stumps of the trees were first discovered in the 1870s near Gilboa, N.Y. Fossilized crowns appeared in places as diverse as Belgium and Venezuela.

The team says the tree holds critical clues to what the forest's ecosystem might have been like. For example, the tree species apparently shed foliage repeatedly as it grew. The large amount of tree litter covering the forest floor would have encouraged the evolution of four-legged foragers, the team speculates. The results appear in today's issue of the journal Nature.

Ethanol: not a pollution solution

Ethanol-based fuel may help wean the United States from foreign oil, but it may not do much to clean the air, according to a study from Stanford University. In some places, air quality may get worse, the research suggests. The study is an early attempt to gauge the effects on pollution and public health of a large-scale shift from gasoline to biofuels.

Mark Jacobson, an associate professor at Stanford, used an advanced pollution and weather forecasting model, along with data on population growth and detailed estimates of future types and amounts of emissions for the US and for key air-pollution hot spots like Los Angeles. Then he compared the effects in 2020 of running the entire US fleet of autos, trucks, and motorcycles with gasoline versus the effect of using a blend of 85 percent ethanol and 15 percent gasoline.

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