"All-Night Streetlights Make Leaves Inedible To Insects, Study Finds"

"Scientists believe artificial light may be affecting natural ecology of plant life by creating extended photosynthesis"

"Streetlights left on all night cause leaves to become so tough that insects cannot eat them, threatening the food chain, a study has found.

Scientists noticed that trees in urban ecosystems showed far less damage than those in more rural areas. Their research, published in Frontiers in Plant Science, has shed light on a potential reason.

“We noticed that, compared with natural ecosystems, tree leaves in most urban ecosystems generally show little sign of insect damage. We were curious as to why,” said the study’s author, Dr Shuang Zhang of the Chinese Academy of Sciences. “In two of the most common tree species in Beijing, artificial light at night led to increased leaf toughness and decreased levels of leaf herbivory.”

Artificial light from streetlights had a surprising effect on the leaves of trees surveyed. The scientists tested two common species of street tree in Beijing: Japanese pagoda and green ash trees. The pagoda trees have smaller, softer leaves that insects prefer to munch on. Researchers thought plants in areas with high levels of artificial light may focus on defence rather than growth, which would mean their leaves would be tougher, with more chemical defence compounds."

Helena Horton reports for the Guardian August 5, 2024.

Source: Guardian, 08/07/2024