Global Ecology and Conservation (Sep 2024)
Artificial light at night decreases phyllosphere microbial diversity and functionality in grassland plants
Abstract
With the rapid expansion of artificial light in the global nocturnal environment, the ecological impacts of artificial light at night (ALAN) on plant communities have garnered increasing research interest. However, the role of phyllosphere microorganisms as mediators in the regulation between ALAN and plants remains unclear. In this study, we conducted a field experiment in natural grassland plots, employing two treatments: one with no artificial light at night (control) and another with artificial light at night (ALAN). We then investigated the response of phyllosphere microorganisms in three grassland plant species (Leymus chinensis, Vicia sepium, and Aster altaicus) to ALAN exposure. The results revealed that the constructive species L. chinensis demonstrated a markedly higher diversity of phyllosphere bacteria and fungi compared to V. sepium and A. altaicus and thus had the most abundant microbial community. However, ALAN exposure reduced the diversity of phyllosphere bacteria and fungi in all three plant species to varying degrees. ALAN induced certain changes to the phyllosphere bacterial community composition, particularly manifesting in a reduction in the abundance of beneficial bacteria, including Sphingomonas, Hymenobacter, Methylobacterium-Methylorubrum, and Bacillus. Compared with phyllosphere bacterial communities, the alterations in phyllosphere fungal communities were more sensitive, characterized by a significant decrease in the abundance of certain fungi, including Zymoseptoria, Mycosphaerella, Cladosporium, and Epicoccum. The functional predictions of phyllosphere bacteria and fungi further corroborate these conclusions. In summary, ALAN exposure may suppress the functional capacity of phyllosphere microorganisms in grassland plants while decreasing the probability of fungal pathogen occurrence.
