New Delhi. Artificial light that runs all night, such as street lights, can make leaves so hard that insects cannot eat them, which can threaten urban food chains. This has come to light in a study.
The study, titled ‘Artificial light at night reduces leaf herbivory in typical urban areas’, was published earlier this month in the journal ‘Frontiers in Plant Science’. The analysis was conducted by Yu Cao, Shuang Zhang and Ke-Ming Ma of the University of Chinese Academy of Sciences (Beijing).
How was the study conducted?
The researchers wanted to investigate how artificial light affects the relationship between plants and insects. To do this, they focused on two common species of street trees in Beijing: Japanese pagodas and green ash trees. Although these trees are similar in many ways, Japanese pagoda trees have small, soft leaves, which insects love to feed on.
The researchers chose 30 sampling locations along main roads that are typically lit by street lights all night. They then measured illumination – the amount of light – at each location and collected about 5,500 leaves to evaluate the effect of light on their properties such as size, hardness, water content and levels of nutrients and chemical defense compounds.
If the leaves were large, it would mean that the plants allowed themselves to grow using their resources (such as nutrients, water and energy). If the leaves were tough and contained high levels of chemical defence compounds such as tannins, it would indicate that resources were allocated for defence.
What was the result of the research?
The researchers observed that for both species of trees, the higher the light level, the harder the leaves. The harder the leaves, the less evidence of insects eating them. The researchers found no signs of insects munching on leaves in areas where there was the most light at night.
Tags: Science
FIRST PUBLISHED : August 17, 2024, 21:23 IST
