Flower colors are changing in response to climate change

https://www.sciencemag.org/news/2020/09/flowers-are-changing-their-colors-adapt-climate-change

Source: By Lucy Hicks, Science | AAAS. 

Excerpt: research [https://www.cell.com/current-biology/fulltext/S0960-9822(20)31267-7] suggests that over the past 75 years, flowers have also adapted to rising temperatures and declining ozone by altering ultraviolet (UV) pigments in their petals. Flowers’ UV pigments are invisible to the human eye, but they attract pollinators and serve as a kind of sunscreen for plants, says Matthew Koski, a plant ecologist at Clemson University. Just as UV radiation can be harmful to humans, it can also damage a flower’s pollen. ...pigment in flowers at all locations increased over time—an average of 2% per year from 1941 to 2017, they reported this month in Current Biology. But changes varied depending on flower structure. In saucer-shaped flowers with exposed pollen, like buttercups, UV-absorbing pigment increased when ozone levels went down and decreased in locations where ozone went up. But flowers with pollen concealed within their petals, such as the common bladderwort, decreased their UV pigment as temperatures went up—regardless of whether ozone levels changed. Though surprising, the finding “makes total sense,” says Charles Davis, a plant biologist at Harvard University who was not involved with the work. Pollen hidden within petals is naturally shielded from UV exposure, but this extra shielding can also act like a greenhouse, trapping heat. When these flowers are exposed to higher temperatures, their pollen is in danger of being cooked, he says. Reducing UV pigments in the petals causes them to absorb less solar radiation, bringing down temperatures....