Plants are flowering at higher elevations in Arizona's Santa Catalina Mountains as summer temperatures rise, according to new research from The University of Arizona in Tucson.
The flowering ranges of 93 plant species moved uphill during 1994 to 2003, compared to where the same species flowered the previous ten years. During the 20-year study period, summer temperatures in the region increased about 1.8 degree Fahrenheit (1 degree C.).
"For years, probably decades now, scientists have been trying to understand how species are going to respond to the anticipated global changes and global warming," said Theresa Crimmins, research specialist for the UA's Arid Lands Information Center and the network liaison for the National Phenology Network.
To better understand how plants respond to climate change, Crimmins and her husband, UA climatologist Michael Crimmins, teamed up with naturalist Dave Bertelsen. He's been hiking the Finger Rock trail about one to two times a week since 1983 and recording what plants were in flower.
The 5-mile hike starts in desert scrub vegetation and climbs 4158 feet (1200 meters), ending in pine forest. Bertelsen has completed 1,206 round-trip hikes and recorded data along the trail for nearly 600 plant species, he said in an e-mail.
Lead author Theresa Crimmins said Bertelsen's data shows that some species flowered farther upslope than before, others stopped flowering at lower elevations, and some species did both.
Because some plant species are moving and others staying put, she said the changes may divide plant communities, increase the growth of invasive species and even cause local extinctions by affecting the food sources of local insects and animals.
"I think we can be confident that things are going to continue to change and we don't necessarily know the ripple effects of all these changes in flowering ranges," Crimmins said.
Theresa Crimmins, Michae
|Contact: Mari N. Jensen|
University of Arizona