HOW DOES ARTIFICIAL LIGHTING AT NIGHT INFLUENCE STREAM ECOSYSTEM METABOLISM?
Artificial light at night (ALAN) has become a pervasive environmental stressor at a global scale. Current research suggests that ALAN may impair individuals and populations, but little research to date addresses effects of ALAN on stream ecosystem functioning. We examine impacts of ALAN on stream metabolism under different regimes of light intensity and spectra, with goals of: (1) observationally assessing changes in measures of stream metabolism over 18 months in streams exposed to long-term street-lighting, (2) continuing assessments for 6 months after experimental street-light removal, and (3) experimentally identifying mechanisms underlying ecosystem respiration changes (lab, field, and mesocosm experiments). Early data suggest that benthic primary productivity and P:R ratios may exhibit non-linear associations with light intensity, as indicated by both lab studies of diatom growth under ALAN and field studies showing decreased contribution of aquatically-derived energy to aquatic and riparian invertebrate consumers at intermediate light levels. We anticipate a reduction in leaf litter decomposition rates via topdown controls under experimental lighting and a time lag in metabolic recovery of streams after light removal. Understanding consequences of ALAN for key ecosystem processes will be critical to developing integrative stream management plans.
Rebecca C. Novello (Primary Presenter/Author), The Ohio State University, email@example.com;
S. Mažeika P. Sullivan (Co-Presenter/Co-Author), The Ohio State University, firstname.lastname@example.org;