The food chain ends in the cone of light
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fromFrederick Reinhardt
shut down
Gentle street lamps to limit insect mortality
The swarm of insects under the street lamps, the dead insects in the glass. The Bergen-Enkheimer Greens are now problematizing this everyday sight in summer. In addition to flowering meadows, they also require insect-friendly lanterns.
A complex experiment at the Friedrich Schiller University in Jena revealed the core of the problem last year. Scientists around the zoologist Gunnar Brehm had installed 95 different light sources in a lecture hall and released more than 6000 moths, many of them native species. The scientists meticulously recorded which animal hit which lamp. Almost all species buzzed towards the light sources. “Our study clearly shows that each individual wavelength is ignited much more strongly than, for example, green or red light,” says Brehm. The effect on butterflies, for example, is problematic because a good 90 percent of the species are nocturnal. When there is heavy light pollution, they fail as pollinators, which causes great ecological and probably also economic damage.
The short-wave light of the LED
According to Brehm, insect deaths in the light cone increase every year. For one thing, night-time light pollution is increasing by two percent every year. On the other hand, many municipalities – including Frankfurt – are converting their street lighting to energy-saving LED lamps. “The new light has a much higher proportion of short-wave blue radiation,” says the study by the University of Jena. The Federal Environment Agency even speaks of a “vacuum cleaner effect”.
Just like a vacuum cleaner attracts dirt and doesn’t let go, street lamps also pull insects out of the air and only let them go again when they burn themselves on the lamp body and are so exhausted from flying around in circles that they have fallen to the ground and die, or are picked off the buffet by predators.
“Billions of insects leave their actual habitat due to the vacuum cleaner effect and can no longer pursue their search for food and partners there,” says the Federal Environment Agency’s insect protection action program. Animals that cannot produce offspring, cannot pollinate plants, and cannot feed other animals. With the vacuum cleaner effect, the food chain ends in the cone of light.
Red light not suitable
“Orange or red light would be ideal,” says zoologist Brehm. However, red light is extremely impractical as street lighting. Warm white LED lamps with color temperatures below 3000 Kelvin are therefore probably the most sensible alternative at the moment.
This is where the application of the Bergen-Enkheim Greens comes in. The parliamentary group will know from the magistrate to what extent the street lighting in the district meets the requirements for insect protection. then “insect-friendly street lighting could sustainably reduce insect mortality,” according to their application.
The Greens are not just concerned with the light sources. “Important influencing factors are illuminance, color temperature and light control, but also organizational measures such as lighting duration or structural measures such as the height of the masts.”
The Greens are not alone in their demands. For years, environmental organizations such as the Naturschutzbund or BUND have been pushing for insects not only to think of the starry sky when it comes to light pollution. In Bavaria and Baden-Württemberg there is already a law to curb light pollution. Frederick Reinhardt
The local council meets 16 times
Tuesday, January 18th, from 7.30 p.m. in the Stadthalle Bergen, Schel- menburgplatz 2.