Contrasting effects of street light shapes and LED color temperatures on nocturnal insects and bats
Street lights are important light sources that contribute to artificial light at night (ALAN). To date, ecological impacts of individual LED properties (color temperature, dimmability) have been studied, while interactions between light properties or aspects of luminaire design have not been address...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-11-01
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| Series: | Basic and Applied Ecology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1439179122000615 |
| _version_ | 1797755044809932800 |
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| author | Janine Bolliger Jörg Haller Beat Wermelinger Stephan Blum Martin K. Obrist |
| author_facet | Janine Bolliger Jörg Haller Beat Wermelinger Stephan Blum Martin K. Obrist |
| author_sort | Janine Bolliger |
| collection | DOAJ |
| description | Street lights are important light sources that contribute to artificial light at night (ALAN). To date, ecological impacts of individual LED properties (color temperature, dimmability) have been studied, while interactions between light properties or aspects of luminaire design have not been addressed. However, the design of luminaires can influence ALAN impacts as the shape determines the spatial distribution of light and its visibility in the environment. This may cause amplifying or mitigating effects. We assessed the relative individual and interacting effects of two LED luminaire designs and three LED color temperatures (1750 K, 3000 K, 4000 K) on nocturnal insect abundance, bat foraging and feeding activity. We considered a standard LED luminaire shape with focused light emission and a luminaire shape with a diffusor to scatter the light spatially, leading to increased visibility of the light in the environment. During 104 nights, we trapped 51263 nocturnal insects of which 97% were caught at lights and 3% at dark sites. For bats, up to 44.8% fewer acoustic signals were recorded at dark sites. We caught 31% insects at LEDs with1750 K, 34% and 35% at 3000 K and 4000 K, respectively. Thus, color temperatures of 1750 K proved less detrimental than 3000/4000 K. Effects of luminaire shape led to an increase (16%) of trapped insects for luminaires with diffusors compared to the standard shape. In addition, luminaires with diffusors amplified the effects of LED color (+12% insects at 1750 K/3000 K; +25.6% at 4000 K). In contrast, bat foraging activity was independent of the light treatments while bat feeding activity was increased by 21.5% at standard luminaire shapes. Likely, intense straylight at diffused lights negatively affects the target-focused echolocation by deterring the bats. We concluded that ecological impacts of luminaire shape are an important, yet underestimated variable in light-pollution impact research. |
| first_indexed | 2024-03-12T17:41:16Z |
| format | Article |
| id | doaj.art-03d981e7858e45db8c0898d3f961ba47 |
| institution | Directory Open Access Journal |
| issn | 1439-1791 |
| language | English |
| last_indexed | 2024-03-12T17:41:16Z |
| publishDate | 2022-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Basic and Applied Ecology |
| spelling | doaj.art-03d981e7858e45db8c0898d3f961ba472023-08-04T05:46:35ZengElsevierBasic and Applied Ecology1439-17912022-11-0164112Contrasting effects of street light shapes and LED color temperatures on nocturnal insects and batsJanine Bolliger0Jörg Haller1Beat Wermelinger2Stephan Blum3Martin K. Obrist4WSL Swiss Federal Research Institute, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland; Corresponding author: Dr. Janine Bolliger, WSL Swiss Federal Reserach Institute, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland, Tel.: +41 44 739 23 93; fax: +41 00 739 22 15EKZ, Dreikönigstrasse 18, 8022 Zürich, SwitzerlandWSL Swiss Federal Research Institute, Zürcherstrasse 111, CH-8903 Birmensdorf, SwitzerlandEKZ, Dreikönigstrasse 18, 8022 Zürich, SwitzerlandWSL Swiss Federal Research Institute, Zürcherstrasse 111, CH-8903 Birmensdorf, SwitzerlandStreet lights are important light sources that contribute to artificial light at night (ALAN). To date, ecological impacts of individual LED properties (color temperature, dimmability) have been studied, while interactions between light properties or aspects of luminaire design have not been addressed. However, the design of luminaires can influence ALAN impacts as the shape determines the spatial distribution of light and its visibility in the environment. This may cause amplifying or mitigating effects. We assessed the relative individual and interacting effects of two LED luminaire designs and three LED color temperatures (1750 K, 3000 K, 4000 K) on nocturnal insect abundance, bat foraging and feeding activity. We considered a standard LED luminaire shape with focused light emission and a luminaire shape with a diffusor to scatter the light spatially, leading to increased visibility of the light in the environment. During 104 nights, we trapped 51263 nocturnal insects of which 97% were caught at lights and 3% at dark sites. For bats, up to 44.8% fewer acoustic signals were recorded at dark sites. We caught 31% insects at LEDs with1750 K, 34% and 35% at 3000 K and 4000 K, respectively. Thus, color temperatures of 1750 K proved less detrimental than 3000/4000 K. Effects of luminaire shape led to an increase (16%) of trapped insects for luminaires with diffusors compared to the standard shape. In addition, luminaires with diffusors amplified the effects of LED color (+12% insects at 1750 K/3000 K; +25.6% at 4000 K). In contrast, bat foraging activity was independent of the light treatments while bat feeding activity was increased by 21.5% at standard luminaire shapes. Likely, intense straylight at diffused lights negatively affects the target-focused echolocation by deterring the bats. We concluded that ecological impacts of luminaire shape are an important, yet underestimated variable in light-pollution impact research.http://www.sciencedirect.com/science/article/pii/S1439179122000615ALANartificial light at nightlight pollutionexperimental biodiversity assessmentlight impactnocturnal biodiversity |
| spellingShingle | Janine Bolliger Jörg Haller Beat Wermelinger Stephan Blum Martin K. Obrist Contrasting effects of street light shapes and LED color temperatures on nocturnal insects and bats Basic and Applied Ecology ALAN artificial light at night light pollution experimental biodiversity assessment light impact nocturnal biodiversity |
| title | Contrasting effects of street light shapes and LED color temperatures on nocturnal insects and bats |
| title_full | Contrasting effects of street light shapes and LED color temperatures on nocturnal insects and bats |
| title_fullStr | Contrasting effects of street light shapes and LED color temperatures on nocturnal insects and bats |
| title_full_unstemmed | Contrasting effects of street light shapes and LED color temperatures on nocturnal insects and bats |
| title_short | Contrasting effects of street light shapes and LED color temperatures on nocturnal insects and bats |
| title_sort | contrasting effects of street light shapes and led color temperatures on nocturnal insects and bats |
| topic | ALAN artificial light at night light pollution experimental biodiversity assessment light impact nocturnal biodiversity |
| url | http://www.sciencedirect.com/science/article/pii/S1439179122000615 |
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