From ragweed to pine trees, plant species are quickly climbing the slopes of the Santa Rosa Mountains in California. Since 1977, nine species of plants native to the region have shifted an average of 213 feet up the mountainsides, dying out at lower elevations and flourishing at higher ones as they pace climate change. A new study tracks the change through several surveys.
The results in Proceedings of the National Academy of Sciences USA add to a growing list of such shifts. Previous work, for example, had found similar shifts in French mountain ranges. In contrast to the French study, all types of plants moved in these California mountains—from quick-growing grasses and wildflowers to slower-growing trees.
"The only thing that could explain this happening across the entire face of the mountain would be a change in the local climate," said graduate student biologist Anne Kelly, lead author of the study in a press release. Added earth systems scientist and co-author Michael Goulden: "It is clear that ecosystems can respond rather rapidly to climate change."
The plants have faced a local 2 degree Fahrenheit rise in temperature, along with several prolonged droughts in the last 30 years (even though overall precipitation was above the historical average). The idea for the study came from residents of nearby Idyllwild, who thought that climate change might be the reason for the death of white fir, Jeffrey pines and California lilacs at their lowest elevations.
Photo courtesy of University of California, Irvine