How does light pollution impact ecological communities? To address this question, many studies measure the abundances of herbivores, predators, detritovores, and other trophic groups in a community. However, past studies often occur over short time scales unlikely to reflect the timespans over which communities actually experience light pollution in the field. To examine longer-term impacts of light pollution on trophic structure, we experimentally manipulated light pollution in a grassland ecosystem and monitored arthropod communities in lit and unlit plots over two years. We collected arthropods via sweep net sampling in eight 20-m diameter plots.
Results/Conclusions
We found no significant difference in the number of individuals captured in lit (739 ± 227 arthropods) and unlit (508 ± 117 arthropods) plots. Additionally, abundances within trophic groups (herbivores and predators) did not differ between lit and unlit plots. These results contrast with previous short-term studies showing dramatic impacts of light pollution on arthropod abundance and trophic structure.