Nav: Home

Light pollution a reason for insect decline

June 19, 2018

Climate change, pesticides and land use changes alone cannot fully explain the decline in insect populations in Germany. Scientists from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) have now discovered that regions that have experienced a sharp decline in flying insects also have high levels of light pollution. Many studies already suggest that artificial light at night has negative impacts on insects, and scientists should pay greater attention to this factor when exploring the causes of insect population declines in the future.

The biomass of flying insects has decreased by more than 75 per cent - this alarming figure made front page news in autumn 2017. The study, published in 2017, analysed trends in biomass of flying insects in selected protected areas within agricultural landscapes over the last 27 years, and concluded that changes of climate and habitat are to blame for the decline in insect populations. At the same time, they pointed out that these impacts alone are unable to explain this drastic decline.

Light at the wrong time disturbs the balance of ecosystems


Clearly an assignment for scientists from the Light Pollution and Ecophysiology research group at IGB. After all, they know from previous studies that artificial lighting at night strongly affects the number of insects and insect communities. Therefore, the team led by IGB researcher Dr. Maja Grubisic looked at the locations of the areas involved in the 2017 study: areas in conurbations that have a higher than average level of light pollution. "Half of all insect species are nocturnal. As such, they depend on darkness and natural light from the moon and stars for orientation and movement or to escape from predators, and to go about their nightly tasks of seeking food and reproducing. An artificially lit night disturbs this natural behaviour - and has a negative impact on their chances of survival", explains Maja Grubisic the starting point of their investigation.

The scientists analysed all recent studies on the effects of artificial light at night on insects, and found that there is strong evidence to suggest a credible link between light pollution and declines in insect populations. For example, flying insects are attracted by artificial lights - and, at the same time, are removed from other ecosystems - and die from exhaustion or as easy prey. Additionally, rows of light prevent flying insects from spreading; causing a lack of genetic exchange within fragmented insect populations that could reduce their resistance to other negative environmental influences, which are especially pronounced in agrarian areas.

A decline in insect populations in agricultural areas - which make up no less than eleven per cent of land use worldwide - does not only mean a decline in species diversity, but also jeopardises important ecosystem services: for example, there are then fewer moths, beetles and flies to pollinate plants. Also, changes in the occurrence and behaviour of pests such as aphids or their enemies such as beetles and spiders can disturb the balance of this well-tuned system. Furthermore, artificial light at night may also have a direct impact on the growth and flowering time of plants, and therefore on yield.

All influencing factors have to be understood and considered - including light pollution


"Our overview study shows that artificial light at night is widely present and can have complex impacts in agricultural areas, with unknown consequences for biodiversity and crop production. Thus, light pollution should be generally considered as a potential ecosystem disturbance in future studies to identify ways in which practical steps can be taken to reduce environmental concerns", summarises Dr. Franz Hoelker, Head of the Light Pollution and Ecophysiology research group at IGB.
-end-
About the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB):

Work at IGB combines basic research with preventive research as a basis for the sustainable management of freshwaters. In the process, IGB explores the structure and function of aquatic ecosystems under near-natural conditions and under the effect of multiple stressors. Its key research activities include the long-term development of lakes, rivers and wetlands under rapidly changing global, regional and local environmental conditions, the development of coupled ecological and socio-economic models, the renaturation of ecosystems, and the biodiversity of aquatic habitats. Work is conducted in close cooperation with universities and research institutions from the Berlin-Brandenburg region as well as worldwide. IGB is a member of the Forschungsverbund Berlin e.V., an association of eight research institutes of natural sciences, life sciences and environmental sciences in Berlin. The institutes are members of the Leibniz Association. http://www.igb-berlin.de/en

Forschungsverbund Berlin

Related Climate Change Articles:

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.
Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.
Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.
Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.
Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.
A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.
Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
More Climate Change News and Climate Change Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.