Study suggests urban planners may need to rethink artifical illumination
By Summit Voice
SUMMIT COUNTY — Street lighting is dramatically changing the balance of natural communities, radically altering he balance of different species living together, according to a new study from the University of Exeter.
This study shows that groups of invertebrates living near artificial lights include more predators and scavengers. This could be impacting on the survival rates of different species, with a cascading effect on birds and mammals that rely on these species for food. The effects could be affecting entire ecosystems and even humans, the researchers said, advocating for more awareness of how lighting affects ecosystems.
Globally, artificial lighting is increasing at about 6 percent annually. Studies have long been documenting how individual organisms are affected, but the Exeter study is the first time that impacts to entire communities have been investigated.
“Our study shows that light pollution could be having a dramatic effect on wildlife in our towns and cities,” said lead author Dr. Tom Davies, of the Environment and Sustainability Institute at the University of Exeter’s Cornwall Campus.
“We need to be aware of how the increase in artificial lighting is impacting on the delicate ecosystems on which we all rely. Our research shows, for the first time, the changes that light pollution is making to entire communities of invertebrates. We now need to examine what impact this is having on other communities and how this may be affecting important ecosystem services and whether we should change the way we light urban spaces.”
The research team based their study in the market town of Helston in West Cornwall. They placed pitfall traps directly under and between street lamps that were 35 metres apart for a number of days and nights. This allowed them to compare, not only results for day and night, but also differences between areas under and away from street lights.
They collected 1,194 individuals covering 60 species. They discovered that total numbers were more abundant under street lights, where they also found more predatory and scavenging species, such as ground beetles and harvestmen. This was the case during the day, as well as at night, suggesting that the effect on communities is ongoing.
The study was published in the May 23 in the journal Biology Letters.