Air pollution changes the way flowers smell, confusing insects
Strange but true
Get a whiff of this.
New research shows that airborne chemicals found in common fossil fuels interfere with the pollination process, so much so that they change the way a flower smells.
Although this may have a minor impact on people who used to stop to smell the roses, the effect on insects – which can no longer locate flowers they land on, especially at night – is worrying, experts say.
“Pollution caused by human activity alters the chemical composition of important odor signals, altering them to the point that pollinators are no longer able to recognize and respond to them,” said researcher Jeff Revell.
Revell and other scientists at the University of Washington, who published their findings in the journal Science, found that nitrate radicals known as NO3 are responsible for the odor masking phenomenon.
They originate from gas, coal, and power plants, in addition to other energy and natural sources.
“When you smell a rose, you’re smelling a diverse bouquet made up of different types of chemicals,” Revell added.
“The same is true for almost any flower. Each has its own scent made up of a specific chemical recipe.
They experimented with moths, which Revell says have a strong, dog-like ability to smell, to see if the winged things could locate specific flowers using their keen sense of smell.
One of the two strains of moths was 50% less accurate, while the other was unable to find the source of the flower at all when tested in a nighttime urban environment.
“NO3 actually reduces the reach of a flower — how far its scent can travel and attract pollinators before it decomposes and becomes undetectable,” Revell said.
However, the daytime statistics were not as serious as the research team believes that sunlight can reduce the forces of NO3.
Regardless, there is now concern that pollinators such as moths will become unable to fulfill their duties in the ecosystem.
Revell noted that about 75% of the more than 240,000 documented flowering plants require insect intervention, and that about 70 pollinator species are endangered or threatened with extinction.
“Our approach can serve as a roadmap for others to investigate how pollutants affect interactions between plants and pollinators, and to get to the underlying mechanisms,” said researcher Joel Thornton.
“You need this kind of comprehensive approach, especially if you want to understand how widespread the breakdown in interactions between plants and pollinators is — and what the consequences are.”