Light pollution shown to affect plant growth and food webs

March 16, 2015
Researchers from the University of Exeter simulated the effects of street lighting on artificial grassland plots containing a community of invertebrates at night, exposing them to two different types of light treatment - a 'white' light similar to newer commercial LED street lighting systems and an 'amber' light simulating the type of sodium street lamp still found in much of the UK. The experiments investigated both top-down (driven by predators) and bottom-up (food or resource limited) effects of the lights on the population density of a species of pea aphid, and in the presence and absence of predators including ladybirds Credit: Jon Bennie/University of Exeter

Artificial night time light from sources such as street lamps affects the growth and flowering of plants and even the number of insects that depend on those plants for food, a study published today confirms.

The research shows that pollution can impact the natural environment in complex ways that may be hard to predict. Due to the global extent of artificial light at night, there are concerns that these ecological impacts may be widespread.

Researchers from the University of Exeter simulated the effects of on artificial grassland plots containing a community of invertebrates at night, exposing them to two different types of light treatment - a 'white' light similar to newer commercial LED street lighting systems and an 'amber' light simulating the type of sodium street lamp still found in much of the UK.

The experiments investigated both top-down (driven by predators) and bottom-up (food or resource limited) effects of the lights on the population density of a species of pea aphid, and in the presence and absence of predators including ladybirds.

The low intensity amber light was shown to inhibit, rather than induce, flowering in greater bird's foot trefoil, a wild relative of peas and beans that is a key source of food for the in grasslands and road verges. In mid summer aphids feed on the flowering shoots; the number of aphids was significantly suppressed under the light treatment in mid-August due to the limited amount of food available.

Professor Kevin Gaston, Director of the Environment and Sustainability Institute (ESI) said: "These are the first findings from major long-term experiments being funded by the European Research Council, and already reveal how profound the impacts of artificial night time lighting can be on even simple communities of organisms."

Dr Jonathan Bennie of the ESI added: "Our results suggest that by lighting up our night time environment we trigger complex effects on natural webs. While we are all aware that street lights often attract insects at night, we show that they may have more permanent, widespread impacts on wildlife and ecosystems."

Explore further: Light pollution transforming insect communities

More information: 'Cascading effects of artificial light at night: resource-mediated control of herbivores in a grassland ecosystem' by Jonathan Bennie, Thomas W. Davies, David Cruse, Richard Inger and Kevin J. Gaston is published in the journal Philosophical Transactions of the Royal Society B.

Related Stories

Light pollution transforming insect communities

May 23, 2012

(Phys.org) -- Street lighting is transforming communities of insects and other invertebrates, according to research by the University of Exeter. Published today in the journal Biology Letters, the study shows for the first ...

Like a moth to a street light

February 5, 2014

A new research project will investigate how street lighting impacts on the many hundreds of species of moths that can be found in Britain. 

Bright lights: big cities at night

December 17, 2014

As the days grow shorter and the temperatures drop in Europe, test your geography skills in the warmth of your home – while helping scientists to pinpoint light pollution.

Intelligent street lights adapt to conditions in Finland

May 27, 2013

VTT Technical Research Centre of Finland has developed a dimmable LED street light that consumes significantly less energy than current lighting systems, while improving the lighting characteristics. The street lights were ...

Recommended for you

Cow gene study shows why most clones fail

December 9, 2016

It has been 20 years since Dolly the sheep was successfully cloned in Scotland, but cloning mammals remains a challenge. A new study by researchers from the U.S. and France of gene expression in developing clones now shows ...

Blueprint for shape in ancient land plants

December 9, 2016

Scientists from the Universities of Bristol and Cambridge have unlocked the secrets of shape in the most ancient of land plants using time-lapse imaging, growth analysis and computer modelling.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.