JACKSON, Wyo. — A recent study by scientists at The Nature Conservancy in Wyoming found bloom times in the Greater Yellowstone Ecosystem (GYE) are nearly three weeks earlier than in the 1970s due to climate change, a difference that can impact the relationship between plants and the animals that depend on them for survival.
The study, which was published in March 2022, observed first-flowering dates for 51 species of wildflowers and other plants in the GYE and compared it with data from the 1970s and 1980s.
According to the study, the largest shift was for early spring flowers like buttercups, spring beauties and hooded phlox that are blooming on average 17 days earlier, but up to 36 days earlier now compared to decades ago. Mid-summer flowers bloom on average 10 days earlier, nonnative species bloom 15 days earlier and berry-producing shrubs bloom five days earlier. Late summer flowering plants were the only ones whose bloom time did not appear to shift.
The study shows a direct correlation between early spring plants’ emergence and snowmelt timing; additionally, the earlier blooming spring flowers can face frost days that cause them to lose their flowers or never produce fruit, according to community ecologist with The Nature Conservancy in Wyoming Trevor Bloom. Because of this correlation with snowmelt and spring temperature, Bloom says it’s likely this rate of change will get exponentially faster.
And the disruption between resource availability and wildlife will impact species from pollinators to predators.
“So often there’s so much of a focus on the charismatic megafauna, but wolves cannot live without elk, elk cannot live without grasses and wildflowers and shrubs and trees for food,” says Kevin Taylor, a botanist and faculty with Wildlife Expeditions. “Plants have this amazing ability to take the sun’s energy, CO2 and water and make food out of it for all these animals to eat. And the byproduct they make is oxygen!”
Greater sage-grouse also depend on spring forbs for nesting and feeding themselves and their babies, grizzly bears depend on berries for their diet before hibernation and pollinators like insects, hummingbirds and butterflies all rely on plants to survive.
Humans also have a significant relationship with plant species locally, and conservation of the flora helps maintain a connection to the landscape. According to Taylor, the smells of wildflowers or certain plants can trigger deep emotions and memories. Wildflowers like daffodils can be part of meaningful traditions and gifts, and plants like arnica can assist in modern healing.
Yet in spite of the increasing bloom time disruption, the unique biodiversity of this valley is the key to supporting and recovering the plant ecology.
“What we have found and what we advocate for is that increased biodiversity is one of our greatest tools to be resilient against climate change,” Bloom says. “The [GYE] has a very diverse ecosystem, over 1400 plants native to Teton County.”
Bloom advocates for protecting the wilderness and what he calls “connected landscapes.” While many typically think of migration as something animal species do, Bloom points out that as the climate changes plant species may have to start moving up in elevation or shifting north.
