A lot of research and attention has been given to how light pollution negatively impacts birds, bats, other animals, and insects. Less well known are the negative impacts of light pollution on plants.
Most people have seen now bright lights at night attract moths. This can significantly change moth behavior. Artificial light at night (ALAN) disrupts moths’ flight patterns enough that it impedes how much, and how well, they pollinate plants. Some researchers found 70% of moths were drawn upwards towards the lights and away from flowering plants, resulting in a noticeable reduction in plant pollination as well as the number of pollen types that were transported by the moths. This was true across several different nocturnal moth species and over 28 varieties of plants, meaning the ripple effect could be widespread.
ALAN disruption of pollinators can also impact the pollen output of plants, which further impacts how pollinators fertilize plants. It’s estimated that a quarter of the planet experiences light pollution at night, worsening by an additional 6% per year. Light pollution has increased by at least 49% over the past 25 years. Pollinator populations are steadily declining and it’s likely due to a combination of light pollution, chemical pollution, climate change, and habitat loss.
In addition to impacting pollinators and pollination, ALAN impacts plant circadian rhythm, and seasonal rhythms. For example, researchers have found that budburst happens up to 7.5 days earlier in areas with bright light pollution.
Plants are like animals in that they need a 24 hour sleep cycle to process, and put attention to different activities at different times of the day. ALAN disrupts the nocturnal activities and creates increased stress on exposed plants.
You can read more in a BBC article here.