Impact of Excessive Artificial Light at Night (ALAN) on Species Diversity of Plants and Epigeic Insects

This study examined the impact of artificial light at night (ALAN) emitted by a lit greenhouse complex in Poland on plant communities and surface-dwelling arthropods. The effects of ALAN were investigated at three different distances from the light source within agricultural ecosystems. Insect populations were sampled using Barber traps, while plant communities were assessed using the Braun- Blanquet method. The findings showed that ALAN did not cause significant overall changes in plant community composition. However, ordination analysis suggested species-specific shifts in response to light pollution, indicating that some plants may adapt differently depending on their proximity to the light source. ALAN caused a notable decrease in arthropod diversity, as measured by the Margalef index; however, not in taxa abundance. These results, based on a single growing season, highlight the potential ecological risks of nighttime lighting for insect biodiversity and emphasise the need for longterm studies to understand its effects fully.