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 elevationsas 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. In some cases, researchers found that the plants had moved upward by as much as 1,000 feet, into a much narrower elevation range than where the plants existed in the early 1960s. Writing in the journal Ecology and Evolution, the researchers note that the lowermost boundary for 15 of the species has shifted upslope.