The interactive effects of artificial light at night and ground-dwelling arthropods on leaf herbivory in urban ecosystems

Artificial light at night (ALAN) is an increasingly intensified disturbance in urban ecosystems, but its effects on ground-dwelling arthropods' biodiversity and their biotic interactions remain unclear. Here, we evaluated the response of ground-dwelling arthropods and leaf herbivory of two common street tree species ( Styphnolobium japonicum (L.) Schott and Fraxinus pennsylvanica ) to ALAN in the urban areas of Beijing, China. We found that 1) ALAN was associated with increased ants' activity in areas dominated by F. pennsylvanica , but there were no detectable effects on beetles and spiders. 2) Ground-dwelling arthropods and their interactions with ALAN were linked to variations in leaf herbivory in both two tree species. These results suggested that the response of ground-dwelling arthropods to ALAN is species-specific and that high levels of ALAN can affect top-down ecological processes in arthropods. The findings confirmed that the ALAN-caused effects on ground-dwelling arthropods can lead to cascading effects on some key ecological effects in urban ecosystems.