Can Wildflowers Adapt?

Can Wildflowers Adapt?

Crested Butte is known for being the wildflower capital of Colorado, and each year, the fields around Gunnison Valley explode in purples, yellows, and reds – many of them in fields you’ve helped the Land Trust protect. In the coming decades, earlier snowmelt, lower snowpack, and hotter temperatures during the growing seasons are all changes that we might expect to see in the Gunnison Valley. And these changes could affect everything from our ski season to our wildflower displays.

Will our wildflowers survive?

Dr. Jill Anderson is studying how a changing climate might impact one native wildflower in particular – Drummond’s rockcress. Dr. Anderson is an evolutionary ecologist. She does her summer research at the Rocky Mountain Biological Laboratory (RMBL), and, thanks to the strong partnership we maintain with RMBL, several of her study plots are on land protected by the Land Trust.

Drummond’s rockcress can grow at elevations as low as 5,000 feet above sea level, all the way up to over 12,000 feet on the higher peaks around Crested Butte. Scientists call this phenotypic plasticity – individual plants can adjust things like their flower and leaf size to be better suited for current conditions. You might think of phenotypic plasticity in yourself as you acclimatize to Crested Butte. Your red blood cell count increases to carry more oxygen, making you better suited for the high elevation conditions.

One of the ways that Drummond’s rockcress is able to adjust to its environment is flowering time. Thanks to Dr. Anderson’s research, as well as Dr. David Inouye’s long-term record, we know that Drummond’s rockcress flowers about 13 days earlier now than it did in the mid-1970s – a result of earlier snowmelt.

There are limits

But, just as there is a limit to the elevation at which humans can survive, there is also a limit to how well our valley’s wildflowers will be able to adapt to climate change.

Dr. Anderson says that she is not yet sure if Drummond’s rockcress will be able to adjust quickly enough to keep pace with climate change.  “Ultimately, I do believe that Drummond’s rockcress will be among our wildflower fields in 50-100 years, although it may not be as abundant as it is now,” she said.

Drummond’s rockcress is especially good at adjusting to changing conditions. Other wildflowers might not fare as well. “Most of the plants in the Gunnison Valley are perennial, which gives them fewer opportunities to adapt. That said, some species will clearly thrive, such as sagebrush. Plants from hot and dry habitats (like sagebrush) will likely have an advantage as the climate gets hotter and drier,” Dr. Anderson said.

“The species that are most vulnerable are climate specialists living in very high elevation locations. These species typically don’t have broad climatic tolerances, so they may begin to dwindle under hotter, drier conditions. High elevation plants and animals (e.g., pika) don’t have many places up in elevation that they can travel to escape new climates, so they are particularly susceptible.”