United Kingdom — In a discovery that would back the long held belief that watering plants in the midday sun can burn them, British researchers have found that the same process could also lead to forest fires.
Researchers at Eotvos University in Hungary found that water droplets on dry and green leaves act as a magnifying glass to sunrays falling on them, causing fire in forests.
Our experiments showed that in sunshine water drops residing on smooth hairless plant leaves are unlikely to damage the leaf tissue,” said lead researcher Gabor Horvath.
“However, water drops held by plant hairs could lead to forest fires, theoretically, if the focal region of drops falls exactly on the dry plant surface.”
The team also suggested that, similarly, exposing hairy human skin to direct sunlight immediately after taking a bath could lead to sunburn.
According to the study, published in New Phytologist, the team carried out both computational and experimental studies to clarify the environmental conditions under which sunlit water drops can cause leaf burn.
They found that water droplets on a smooth surface, such as maple or ginkgo leaves, do not cause leaf burn.
However, floating fern leaves that have small wax hairs are susceptible to leaf burn as hairs on the surface holds water droplets in focus acting as a magnifying glass.
The same phenomenon can lead to sunburns in humans when water droplets are held on the skin by body hair,” Hovarth added.