Skyglow and especially direct streetlight pollution alter moth communities

Area of Science:

• Ecology
• Environmental Science
• Conservation Biology

Background:

• Artificial light at night (ALAN) is a growing global environmental issue impacting biodiversity.
• The effects of indirect skyglow and direct streetlight pollution on species communities are often studied separately.
• Urbanization can confound the assessment of ALAN's direct effects on ecosystems.

Purpose of the Study:

• To investigate the additive effects of skyglow and direct streetlight pollution on garden moth communities.
• To determine how ALAN conditions influence the morphological, behavioral, and life-history traits of moth communities.
• To understand the combined impact of different types of light pollution on insect biodiversity.

Main Methods:

• Sampling of garden moth communities under varying levels of skyglow and direct streetlight pollution.
• Analysis of moth abundance, species richness, and diversity in relation to light pollution.
• Correlation of ALAN impacts with species' traits, including life-history and habitat preferences.

Main Results:

• Both skyglow and streetlights significantly reduced moth abundance.
• Direct streetlight pollution decreased species richness and diversity, irrespective of skyglow levels.
• ALAN altered moth community composition, with skyglow filtering by hibernation stage and larval habitat, and streetlights by voltinism, diet, habitat openness, and hibernation stage.

Conclusions:

• Both skyglow and, more significantly, streetlight pollution negatively affect moth communities.
• Declines in moth populations have implications for food webs and pollination services.
• ALAN acts as a filter on species and their traits, necessitating consideration of multiple light pollution types in future research.