As any city-dweller knows, the pavement can be a gloomy place, with tall buildings blocking out the sun for much of the day. You’d imagine the same would be true within a forest, but it turns out that plants have evolved a clever trick to redirect sunlight and bring the weather they want down into the forest understory.
All plants produce chemicals, known as volatile organic compounds. Emitting these chemicals uses a significant amount of the plant’s energy, so why do they do it? Alexandru Rap from the University of Leeds, and colleagues, investigated this question by comparing plant productivity with the amount of volatile organic compounds in the air. Their findings, published in Nature Geoscience, show that plant volatiles are significantly boosting vegetation productivity. In this case it seems that the mist of chemicals above a forest changes the direction of incoming sunlight, enhancing the amount of diffuse light (coming in from low angles).
“Amazingly we found that by emitting volatile gases forests are altering Earth’s atmosphere in a way which benefits the forests themselves. We found that the forests get back more than twice as much benefit, through the effect the increased diffuse light has on their photosynthesis,” says Rap.
