Carbon Dioxide Use by Trees Studied

Researchers had hoped that forests might slow the accumulation of carbon dioxide in the atmosphere from the burning of fossil fuels--a primary contributor to the planet-warming greenhouse effect. But a new study at Duke University is less optimistic. Biologist Ram Oren and his colleagues reported in the May 24 Nature that a plantation of trees growing in an atmosphere containing nearly twice the current level of carbon dioxide did grow faster for the first three years, but then reverted to normal growth rates. The team concluded that the slower growth, and thus the reduced consumption of carbon dioxide, was limited by the lack of nutrients in the soil, particularly nitrogen compounds. Adding nitrogen to the soil caused the rate to increase again.

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Compiled by Times medical writer Thomas H. Maugh II.