A framework for untangling the consequences of artificial light at night on species interactions

Abstract

Although much evidence exists showing organismal consequences from artificial light at night (ALAN), large knowledge gaps remain regarding ALAN affecting species interactions. Species interactions occur via shared spatio-temporal niches among species, which may be determined by natural light levels. We review how ALAN is altering these spatio-temporal niches through expanding twilight or full Moon conditions and constricting nocturnal conditions as well as creating patches of bright and dark. We review literature from a database to determine if ALAN is affecting species interactions via spatio-temporal dynamics. The literature indicates a growing interest in ALAN and species interactions: 58% of the studies we analysed have been published since 2020. Seventy-five of 79 studies found ALAN altered species interactions. Enhancements and reductions of species interactions were equally documented. Many studies revealed ALAN affecting species interactions spatially, but few revealed temporal alterations. There are biases regarding species interactions and ALAN—most studies investigated predator–prey interactions with vertebrates as predators and invertebrates as prey. Following this literature review, we suggest avenues, such as remote sensing and animal tracking, that can guide future research on the consequences of ALAN on species interactions across spatial and temporal axes. This article is part of the theme issue ‘Light pollution in complex ecological systems’.

Light pollution in complex ecological systems

“…Such changes in processes and functions can have strong consequences for species interactions and ecological networks that constitute entire communities [53]. Specifically, Seymoure et al [54] highlight the fast-growing realm of study in ALAN biology, by putting forth a framework to study species interactions under ALAN, while Heinen et al [31] and Dyer et al [35] both put this work into action in plant-insect community experiments. For example, Heinen et al [31] report a largely indirect effect of ALAN on plant defence through herbivory, with ALAN altering herbivore population size which then upregulates plant defences.…”

“…Specifically, Seymoure et al . [ 54 ] highlight the fast-growing realm of study in ALAN biology, by putting forth a framework to study species interactions under ALAN, while Heinen et al . [ 31 ] and Dyer et al .…”