Welcome urban nomads to the second post on Light Pollution in Singapore. As Singapore continues to use artificial lights in the promotion of Singapore as a metropolitan hub which draw tourists worldwide, there has been a lot of negative impacts from this light pollution. Today, we will be looking at the flora and fauna which have been affected by light pollution.

Impact on the trees in Singapore

While many are familiar about how light is vital in photosynthesis, in contrast, there has been very little information on how photoperiod ( day length) can affect vegetative growth and the reproduction of plant (Meier et al., 2015). During periods of uninterrupted durations of darkness, which is typically occurring at night, plants have capitalized on this for the developmental processes that facilitates the growth of plants.

Based on the absorption of either red (625-760 nm) or infrared (760- 850 nm) wavelengths of radiation, a photo-reversible pigment called phytochrome is able to “tell’ the different time during the day (Meier et al., 2015). As phytochrome are light sensitive, even a small brief burst of light can create physiological conditions which are similar to daytime, thereby disrupting the development of plants (Meier et al., 2015).

Different wavelength of lights

Furthermore , prolong exposure to light results in an increase duration of photosynthesis, causing  stomata in leaves to stay open, subjecting to an increase risk of suffering from air pollution ( more so if trees are planted by the side of roads.

The Beautifying of the landscape to appeal to tourist results in light pollution on trees in Clarke Quay

Impact on Bird species

Many of the bird species such as the songbird, waterfowl and shorebird are only able to migrate at nightfall, with the help of moon and starlight for navigation (Ouyang et al., 2017).

Singapore, being heavily polluted with excessive artificial lighting extends to the airspace above resulting in skyglow. This therefore hampers the birds ability to migrate as these  artificial lights have the ability to disorient migratory birds, affecting their flight trajectories; creating a phenomena called fatal light attraction (Ouyang et al., 2017). As such, some of these birds stray off course and collide into adjacent illuminated buildings and towers.

Based on studies, between 1998 and 2016 in Singapore,  there has been an estimated 237 migratory birds collided with buildings. As Singapore happens to be part of the East Asian-Australasian Flyway, between September to March every year, migratory birds that may originate as far off from Siberia use Singapore as a resting point when travelling to Australia (Ouyang et al., 2017).

East Asian-Australasian Flyway.

Below, I will include a few examples of bird species which are affected by the light pollution in Singapore.

Blue-winged Pitta

Yellow-rumped Flycatcher

To conclude, Singapore has paid a price for being a metropolitan hub, in hopes of attracting tourist at possible expense on not just human health, but also on local biodiversity. More should be done to tackle this issue. Perhaps, the next time you marvel at the city skyline of Singapore, do know that this beauty of modernity comes at an ugly cost.

An interesting video that I stumbled across.

References

• Meier, J., Hasenöhrl, U., Krause, K., & Pottharst, M. (2015). Urban lighting, light pollution, and society. New York: Routledge, Taylor & Francis Group.
• Ouyang, J. Q., de Jong, M., van Grunsven, Roy H. A, Matson, K. D., Haussmann, M. F., Meerlo, P., . . . Spoelstra, K. (2017). Restless roosts: Light pollution affects behavior, sleep, and physiology in a free-living songbird. Global Change Biology, 23(11), 4987-4994. doi:10.1111/gcb.13756

• Kocifaj, M. (2011). A numerical experiment on light pollution from distant sources. Monthly Notices of the Royal Astronomical Society, 415(4), 3609-3615. doi:10.1111/j.1365-2966.2011.18977.x