Utah is coming out of a record-breaking warm winter, and nature is responding.
“If you've been walking around already in — God, in December of last year — or even now, you're starting to see stuff in flower,” said Jim Cohen, chair of the Department of Botany and Plant Ecology at Weber State University.
Along with students and fellow professor Heather Root, Cohen has been studying how warmer temperatures affect when flowers start to emerge.
“What we found is that when it is one degree warmer [Celsius] than the historic average, that plants are flowering a little more than five days earlier than they had been,” he said.
He said that’s consistent for most of the 30 species across the Wasatch and Uinta mountains that they’re looking at.
Plants at lower elevations tend to flower earlier than plants of the same species at higher elevations, so the researchers controlled for that variable. Even so, if the unseasonable temperatures continue through the spring, Root expects that to make a difference.
“If we keep having a warm spring, that will continue to affect the plants that bloom in July,” she said. “And if we had a warm winter, and now we're done being warm, and we have a cool rest of the spring, then only the early spring plants would be affected, and the later plants would probably not.”
A heat wave is expected, though, at least in the near-term, said Jon Meyer, assistant state climatologist at the Utah Climate Center.
“We're going to confuse a lot of the plants with these kind of spring experiences,” he said.
A spring freeze could still be in the cards, Meyer cautioned. And if that happened post-bloom, it could hurt crops, especially fruit orchards.
It’s now common for a season to be warmer than average, Meyer said. Utah is about 1 to 1.5 degrees Celsius warmer than historical temperatures, and above-average weather is likely to continue through the spring.
Over a longer view, conditions that may have happened once in a century are now occurring once in 10, 25 or 50 years, Meyer said.
For their research, Cohen and Root pored through dried plant samples stacked in manila folders in their lab. Weber State’s herbarium dates back to the school’s founding in the late 1800s.
“It's kind of like a time machine, because you can go back and you can see what the plants were doing at a particular place at a particular time,” Cohen said.
The samples are labeled with the date and location of their collection, so the researchers compared dates of flowering with temperature data from that year.
Cohen loves flowers and is always happy to see them bloom, but he wonders about potential consequences.
“There are pollinators, there are herbivores, other plants that rely on these plants to be out at particular times,” he said. “And if there are shifts that are too rapid, then it can be challenging for other organisms that rely on them, and that can have the ripple effect.”
For their part, biologists with the Utah Division of Wildlife Resources said early blooms don’t have much of an impact on deer or elk, according to an agency spokesperson.
While she hasn’t studied it, Root said it’s possible that plants and pollinators could fall out of sync, which would affect the greater food web.
“Flowering earlier and not successfully getting pollinated now means, like, you've wasted that energy that you can't use for other things, if you're a plant,” she said. “So it would be really interesting to look at, like, those downstream implications.”
Macy Lipkin is a Report for America corps member who reports for KUER in northern Utah.
