Researchers at the University of Virginia say that pollution is dramatically cutting the distance travelled by the scent of flowers. Professor Jose Fuentes, who led the study, said: "Scent molecules produced by flowers in a less polluted environment could travel for roughly 1,000 to 1,200 metres. But today they may travel only 200 to 300 metres. This makes it increasingly difficult for bees and other insects to locate the flowers."
The researchers – who worked on the scent given off by snapdragons – found that the molecules are volatile, and quickly bond with pollutants such as ozone and nitrate radicals, mainly formed from vehicle emissions. This chemically alters the molecules so that they no longer smell like flowers. A vicious cycle is therefore set up where insects struggle to get enough food and the plants do not get pollinated enough to proliferate.
Already bees – which pollinate most of the world's crops – are in unprecedented decline in Britain and across much of the globe. At least a quarter of America's 2.5 million honey bee colonies have been mysteriously wiped out by colony collapse disorder (CCD), where hives are found suddenly deserted.
