Carbon dioxide concentrations in the atmosphere continue to climb because of human activities. Although most commonly flagged as a cause of global warming, a different feature involving the gas may have an impact on the world's biota. Carbon dioxide is a raw material for photosynthesis. Moreover, current concentrations are low enough to limit the synthesis of foodstuffs by some kinds of plants. Because of this, some people have suggested that the continued rise in the concentration of the gas will be to the good, increasing plant productivity.
This may be a dangerous stance to take until we get more information.
The potential difficulty is that some plants will increase productivity, but others are
not limited by carbon dioxide concentrations and thus do not respond positively as the
gas becomes more common. This imbalance implies upsets in natural communities as some
plants become more competitive. Imported exotic species, especially, may be
overwhelmingly aggressive. Little study has been made of the carbon dioxide
requirements of Chihuahuan Desert species—we can only stay tuned for the great
on-rushing experiment.
Listen to the Audio (mp3 format) as
recorded by KTEP, Public Radio for the Southwest.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
Moore, P. D. 2004. Favoured aliens for the future. Nature 427:594.