Plants in U.S. Southwest Moving Higher as the Climate Warms

Numerous plant species on a mountain in the southwestern U.S. are migrating to higher elevations as the climate gets warmer and drier, according to a new study.

After comparing the results of a recent survey of 27 plants found on Mount Lemmon, a 9,157-foot peak near Tucson, Ariz., with a similar survey conducted in 1963, researchers at the University of Arizona found that three-quarters of the plants have shifted their range "significantly" upslope in the last five decades.

Writing in the journal Ecology and Evolution, the researchers note that the lowermost boundary for 15 of the species has shifted upslope. "If climate continues to warm, as the climate models predict, the subalpine mixed conifer forests on the tops of the mountains -- and the animals dependent upon them -- could be pushed right off the top and disappear," said Richard C. Brusca, a research scientist who led the study.

Plants in U.S. Southwest Moving Higher as the Climate Warms