Light pollution – a biodiversity threat: Impact on insect fluxes across ecosystem boundaries

Application summary

Insect biodiversity is declining at an alarming rate. Light pollution has been identified as one contributing factor, yet its impact remains poorly known. Aquatic insects with terrestrial life stages are critical components of both aquatic and terrestrial ecosystems, transferring energy and matter between the two while being increasingly exposed to artificial light. We will investigate how light pollution affects the flux of aquatic insects from streams to forests, and the consequences this has for both the aquatic and the terrestrial ecosystems. We will manipulate light conditions in five streams and assess the effects on insect abundances and diversity in the water, during emergence from the water, and in the adjacent terrestrial ecosystems. In addition, we will explore the potential of aquatic insects to genetically adapt to light pollution through a laboratory experiment, using populations sampled along an urban-rural gradient and reared for several generations under light pollution and control conditions. The results will advance our understanding of how rising light pollution affects the connectivity between two critical ecosystems, the potential long-term consequences, including genetic adaptation to the pollutant, and the modifications to lighting systems that are needed to mitigate negative impacts on biodiversity and ecosystem functioning of both freshwater and terrestrial habitats.