21st Century May Belong to the Shrub
By Stephen Leahy
Sep 1 (IPS) – As atmospheric carbon dioxide levels continue to climb shrubs and other woody plants will likely dominate grasslands, altering pastoral lifestyles around the world, a U.S. study has found.
In the first experiment of its kind done on native grassland, U.S. scientists artificially doubled carbon dioxide (CO2) levels over enclosed sections of prairie in Colorado, a state in the western United States, for five years. To their surprise, one shrub species, Artemisia frigida — commonly known as fringed sage — thrived under those conditions. In fact, it grew 40 times faster than normal, dominating other plant species.
“This kind of response to higher CO2 levels is almost unprecedented,” said Jack Morgan, a plant physiologist at the U.S. Department of Agriculture, and lead author of the study, published Aug. 28 in the ‘Proceedings of the National Academy of Sciences‘ (PNAS), a science journal.
“Fringed sage is a minor species on the landscape normally. We were not expecting to see this,” Morgan told IPS.