Interactive Effects of Artificial Light at Night and Insect Herbivory on the Primary Productivity of Native versus Invasive Plants 81 views

Artificial light at night (ALAN) is a growing phenomenon affecting an increasing number of ecosystems and environments. ALAN can affect plant growth, plant interactions with invertebrates, and invasions by alien plant species. However, studies assessing whether ALAN has differential effects on the growth and reproduction of native versus invasive plants and their interactions with herbivores and pollinators remain limited. I conducted field experiments over two years to investigate the interactive effects of ALAN of differing spectra, broad-spectrum “white” light and narrow-spectrum amber light, and native versus invasive status on plant growth and reproduction traits, insect herbivory, and pollinator visitation. The experiments were conducted using confamilial pairs of native and invasive plant species, four pairs during the first year and three pairs during the second year. I found that white ALAN increased the number of flowers for the native plant species but not the invasive species in the first year. In the second year, white ALAN significantly decreased the number of flowers and the number of pollinator visits for the invasive plants while there was no change for the native plants. Pollinator community composition also differed significantly between ALAN spectra. ALAN had an inconsistent or negligible effect on plant height, leaf length, proportion of leaves damaged, and biomass. These findings suggest that ALAN has important effects on traits important for plant sexual reproduction, with white ALAN apparently favoring native over invasive plant species through effects on flower production.

MS (Master of Science)

Artificial light at night; light pollution; herbivory; invasive species

English

2025-12-04