Ever think the scent of the great outdoors is so much better out of town than in? Well, it’s because it is, according to “Silence Of The Plants,” Marta Zaraska, NewScientist (17 February 2018, paywall), an article on how plants communicate with each other:
Now we are discovering that air pollution can disrupt these communications. In one study, Blande and his colleagues put individual bumblebees into a chamber containing paper flowers resembling those of black mustard. When the scientists injected the scent of real black mustard flowers that grew in either a clean or polluted atmosphere the bumblebees’ reactions were unequivocal: they were immediately attracted to the unpolluted scent, while that from polluted air left them buzzing around aimlessly.
What’s going on? In the past few years, ozone and nitrogen oxides have emerged as the main gibberish-inducing culprits. These ultimately result from vehicle and power plant emissions, with diesel exhaust a particular problem. Both ozone and nitrogen oxides react with the volatile chemicals released by plants. This changes the smell of their bouquet by degrading some compounds in the mix more readily than others. When monoterpene limonene, a common “word” of oranges, is mixed with ozone, for example, it degrades into as many as 1200 different compounds.
Such degradation can happen surprisingly fast. Ecologist Robbie Girling at the University of Reading, UK, and his colleagues exposed eight common compounds produced by flowers to diesel exhaust. “What we weren’t expecting was the speed with which these reactions seem to be occurring,” he says. “Within a minute, which is the shortest time period our method could resolve, we couldn’t see anything of one of the compounds. It was instantaneously undetectable.” (See “When plants talk dirty”)
This strikes me as an example of how emission-less vehicles will improve our living environment, regardless of whether their electricity is derived from renewables or fossil fuels, because in the latter case it’s far more likely that we can effect some sort of air-scrubbing / capture of the noxious fumes before release of the final by-product; having a million cars with local, inferior air-scrubbers is not a great solution. And if the electricity is from renewables, so much the better, even granting that such sources will have their own distinct problems.
Of course, bicycles would be even better – unless human sweat can also interfere with the plants’ language, which is actually not a joke, just some wonderment on my part.
