The Dark Side of Light: Effects of Light Pollution on Insects and Agriculture

LpS 2018 - Lighting Applications
27 Sep 2018

The Dark Side of Light: Effects of Light Pollution on Insects and Agriculture

In recent decades, the use of artificial illumination has rapidly increased, transforming nocturnal environments worldwide. Inappropriate and extensive use of artificial illumination results in light pollution: an increase in nocturnal light above natural levels and a disruption of natural light cycles. Light/dark cycles have been stable over geological and evolutionary timescales, and most organisms rely on light as information source to regulate internal processes through circadian clocks. Furthermore, many organisms evolved to be night-active, to perform their activities in what are naturally dark and dim night environments. Today, as almost a quarter of Earth’s land experience light pollution, this novel, pervasive and widespread environmental change raises concerns about potentially adverse effects on organisms and processes in nocturnally-lit ecosystems. As mounting evidence shows that artificial light at night affects microorganisms, plants, animals and humans, light pollution is increasingly recognized as a global concern and a threat to biodiversity.

In my talk I will give an overview of the recent research into ecological effects of artificial light at night with focus on insects, and discuss how various lethal and sub-lethal impacts of artificial illumination can increase environmental pressure on insect populations and threaten their survival. Alarming rates of declines in insect populations have been increasingly reported, including observations from light-polluted areas. The role of artificial illumination in these negative trends needs to be considered in order to mitigate its adverse effects and allow for recovery of insect fauna in our landscapes.

Insects play important ecological roles in nature, and they are of key importance in agricultural ecosystems where they provide vital ecosystem services such as crop pollination and natural pest control. Therefore, negative impacts of light pollution on insects may have important consequences for agricultural production. By changing composition of insect communities and interfering with predator-prey interactions, artificial light at night may alter balance of species interactions and energy flows in the agroecosystem. Simultaneously, artificial illumination can directly influence physiology and productivity of crop species in its surrounding. How these impacts at different ecosystem levels interact to influence crop production and biodiversity is still not clear, and urgently requires attention given the importance of agriculture for humanity and a large potential for unintended impacts of artificial illumination.

While artificial illumination undoubtedly provides benefits to humanity, it often has negative unintended impacts on our environment. Ecological effects of light pollution are complex, but there is a large potential to mitigate these by developing technological solutions and lighting schemes and strategies. It is only in close collaboration with lighting industry, engineers, planners and designers that we can create and implement adequate solutions to reduce adverse ecological effects of light pollution.