Environmental News for a Healthier Planet and Life

The Climate Crisis Is Changing the Color of Flowers

The Climate Crisis Is Changing the Color of Flowers
Flowers like bladderwort have changed their UV pigment levels in response to the climate crisis. Jean and Fred / CC BY 2.0

As human activity transforms the atmosphere, flowers are changing their colors.

A study published in Current Biology this month found that the ultraviolet (UV) pigmentation of certain flowers had changed in response to the climate crisis and the depletion of the ozone layer. While this isn't something that would be visible to the human eye, flowers rely on their UV patterns to attract pollinators. If those patterns change, it could seriously impact the ability of plants to reproduce.

"This has implications for plant reproduction of both native wildflowers and domesticated crop species that have UV floral patterning like canola and sunflowers," study coauthor and Clemson University scientist Matthew Koski told the Clemson Newsstand. "Altered UV floral coloration has the potential to disrupt pollination services."

To achieve his results, Koski traveled to Europe, Australia and North America and collected plant specimens dating from the 1940s to 2017. All in all, he and his team looked at 1,238 specimens to see how and if their UV pigmentation had responded to changes in UV exposure and temperature.

Overall, they found that UV pigmentation increased by two percent each year. This makes sense because flowers use UV pigment to protect their pollen from UV radiation, Science explained. In an earlier study, Koski had found that flowers living in areas with more UV exposure, such as higher altitudes, had more UV pigment. This finding matched the researchers' prediction that flowers would evolve to make more pigment as ozone levels declined and UV radiation exposure increased.

However, the flowers' responses to both ozone and temperature changes were heavily influenced by whether the flowers had exposed pollen or not, Science explained.

Flowers With Exposed Pollen: For these saucer-shaped flowers, like buttercups, UV pigmentation went up when ozone declined and went down when ozone rose.

Flowers with Concealed Pollen: For these flowers, such as bladderwort, UV pigment levels were determined by temperature, not radiation exposure. If temperature went up, pigment levels fell, even if ozone levels also declined.

This is because concealing pollen in petals can protect it from UV exposure but also expose it to additional heat, Harvard plant biologist Charles Davis, who was not involved with the study, told Science. When temperatures rise, the extra protection risks overheating the pollen. Reducing UV pigment also reduces the amount of solar radiation the petals absorb and can therefore help keep pollen cool.

Pigment changes could impact plants' ability to attract pollinators because pollinators are attracted by a "bull's-eye" pattern that contrasts high and low UV pigment, Koski explained. Altering pigment levels could also alter the effectiveness of this pattern.

Koski told the Clemson Newsstand he hopes to continue his research, in part by investigating further how changes in flower pigmentation will impact their ability to attract pollinators. He also hopes to determine if changes to ozone and temperature alter flowers' visible hues.

By Frank La Sorte and Kyle Horton

Millions of birds travel between their breeding and wintering grounds during spring and autumn migration, creating one of the greatest spectacles of the natural world. These journeys often span incredible distances. For example, the Blackpoll warbler, which weighs less than half an ounce, may travel up to 1,500 miles between its nesting grounds in Canada and its wintering grounds in the Caribbean and South America.

Read More Show Less

EcoWatch Daily Newsletter

Kevin Maillefer / Unsplash

By Lynne Peeples

Editor's note: This story is part of a nine-month investigation of drinking water contamination across the U.S. The series is supported by funding from the Park Foundation and Water Foundation. Read the launch story, "Thirsting for Solutions," here.

In late September 2020, officials in Wrangell, Alaska, warned residents who were elderly, pregnant or had health problems to avoid drinking the city's tap water — unless they could filter it on their own.

Read More Show Less


Eat Just's cell-based chicken nugget is now served at Singapore restaurant 1880. Eat Just, Inc.

At a time of impending global food scarcity, cell-based meats and seafood have been heralded as the future of food.

Read More Show Less
New Zealand sea lions are an endangered species and one of the rarest species of sea lions in the world. Art Wolfe / Photodisc / Getty Images

One city in New Zealand knows what its priorities are.

Dunedin, the second largest city on New Zealand's South Island, has closed a popular road to protect a mother sea lion and her pup, The Guardian reported.

Read More Show Less

piyaset / iStock / Getty Images Plus

In an alarming new study, scientists found that climate change is already harming children's diets.

Read More Show Less