Artificial light pollution disrupts entire ecological networks

A compilation of scientific papers published in the journal Philosophical Transactions of the Royal Society B has recently highlighted the extensive impact of light pollution on ecological systems. 

This special theme issue, led by the German Center for Integrative Biodiversity Research (iDiv) and Friedrich Schiller University Jena, includes 16 papers that explore how even low levels of artificial light at night can disrupt ecosystems, affecting everything from soil and grassland communities to insects.

Light pollution

The increasing prevalence of light pollution is altering night skies globally at a rapid pace, growing annually by up to 10 percent. 

This change disrupts the natural light cycles that have been a constant throughout Earth’s history, cycles crucial for many organisms that depend on light for energy and information.

Focus of the study

Unlike previous studies which focused mainly on human health and individual species, this collection delves into the broader effects on whole ecosystems, considering the complex interplay of species within these systems. 

Dr. Myriam Hirt of iDiv and the University of Jena, who spearheaded the theme issue alongside Dr. Remo Ryser, has argued that “species do not exist in isolation but rather interact in numerous ways.” The goal was to gain a deeper understanding of how brightening night skies affect entire ecosystems and their functionalities.

Impacts of artificial light 

The research, conducted in part using the iDiv Ecotron – a facility housing multiple experimental ecosystem chambers – revealed several key impacts of artificial light. 

These include its reach into belowground soil communities, affecting soil basal respiration and carbon-use efficiency; its influence on invertebrate activity and predation rates; its effect on plant biomass, diversity, and traits; and its potential to homogenize active periods of different species, increasing overlap and extinction risks within communities.

Ecological networks 

Importantly, the studies demonstrate that even low-intensity light pollution can profoundly affect not only individual species but also entire communities and ecological networks like food webs. 

“Their individual responses to artificial lighting and their relationships with one another determine the outcome for the entire ecological system,” Ryser said.

Indirect effects

One study within the issue explored indirect cascading effects of artificial light on humans, particularly through changes in mosquito behavior, which could impact the transmission of vector-borne diseases like malaria. Another paper examined various lighting strategies to mitigate these effects. 

However, the issue emphasizes that mitigation strategies need to be species-specific due to the varied impact of light pollution across different species.

Study implications 

The collective findings of this special issue underscore the significant cost of increasing artificial lighting on both human health and ecosystems. They aim to inspire future research and initiatives to mitigate light pollution’s harmful effects and promote sustainable coexistence between human needs and the natural world. 

“The benefits of artificial light during the night are undeniable, but its adverse effects should not be ignored,” Hirt concluded.

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

—-

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.