ALANizer: Design and validation of experimental lighting rig for studying artificial light at night in ecosystems

Over the past few centuries, human activity has introduced astoundingly bright light to the environment at a rapidly accelerating pace. Artificial light at night (ALAN) has detrimental effects on a wide range of organisms, including arthropods. To minimise impact, we must understand how different organisms are affected and whether certain lights are less perturbing. We designed a novel tool for introducing and monitoring different types of ALAN, called ALANizer, composed of open-source software and inexpensive, widely-available hardware. We describe the design and assembly of ALANizer, as well as a feasibility study where we installed 12 ALANizers in hedgerows and monitored arthropod activity using pitfall traps. We found that ALAN presence increased the total biomass of captured arthropods, the number of arthropods captured, and the total biomass divided by total count (average specimen weight per pitfall trap). Across these three metrics, we observed similar results under white and amber ALAN. Understanding ALAN’s impacts on ecosystems only grows more pressing as LED technology proliferates. As an effective, low-cost, and scalable tool for introducing and monitoring ALAN in ecosystems, ALANizer can help advance this key area of research.