Turn off Street Lights for Part of the Night Brings Ecological Benefits, Says Study
Turn off LED Street Lights for Part of the Night Brings Ecological Benefits, Says Study
People are becoming more aware of the effects of artificial lighting on the human body and wildlife, especially the impacts of lighting at night. A new study led by researchers from Newcastle and York universities found that street lights may disrupt plant pollination as they attract moths; however, by switching off street lights for part of the night, the interruption can be minimized.
Apart from bees, moths also play an important role in the pollination of plants to supplement the day-time work of bees and other pollinating insects. These night-time pollinators are critical even for food production, as they help pollination for food crops such as peas, soybean and oilseed rape. Lighting at night disturbs pollination by attracting moths to the light source so that they would be away from the fields and spend fewer time feeding and pollinating.
Nevertheless, the study found that the pollination result of part-night lighting is the same as full darkness. Dr. Darren Evans, Reader in Ecology and Conservation at Newcastle University, who supervised the study, noted, "We know that light pollution significantly alters moth activity and this in turn is disrupting their role as pollinators. But what our study showed was that while full-night lighting caused significant ecological disruption, part-night lighting did not appear to have any strong effect on pollination success or quality."
The research team compared the impact of a range of scenarios on the pollination of moth-pollinated flowers placed underneath street lights. These included both types of lighting (HPS and LED Street Light), run either all night or switched off at midnight. Results were compared to pollination under natural darkness. The results showed that the full-night lighting led to the greatest ecological disruption while the disruption to the plants' pollination was minimal compared to full darkness. Meanwhile, there is no difference in ecological disruption between LED and HPS lighting.
Lead author Dr. Callum Macgregor, a Postdoctoral Research Associate from the University of York, said, "Often, as conservationists, we have to make difficult trade-offs between development and environmental protection. However, our study suggests that turning off street lights in the middle of the night is a win-win scenario, saving energy and money for local authorities whilst simultaneously helping our nocturnal wildlife."