a study published in Nature, an artificial
light at night disrupts nocturnal pollination networks and has negative
consequences for plant reproductive success. In
artificially illuminated plant-pollinator communities, nocturnal visits to
plants were reduced by 62% compared to dark areas. Notably, this resulted in an
overall 13% reduction in fruit set of a focal plant even though the plant also
received numerous visits by diurnal pollinators. Furthermore, by merging
diurnal and nocturnal pollination sub-networks, we show that the structure of
these combined networks tends to facilitate the spread of the negative
consequences of disrupted nocturnal pollination to daytime pollinator
communities. Our findings demonstrate that artificial light at night is a
threat to pollination and that the negative effects of artificial light at
night on nocturnal pollination are predicted to propagate to the diurnal
community, thereby aggravating the decline of the diurnal community. (Fig.1, 2)
Fig.1. Pollinator visits of artificial
lights at night are 62% more lowered than those of nature darkness
In fact, over the past two decades,
artificial light production has increased by 70%, especially in inhabited
areas. Nighttime artificial light is growing at an annual rate of 6% worldwide.
"In the areas with high levels of light pollution, light-sensitive
insects have already disappeared," Dr. Knob said.
Artificial lights at night lowered pollinator visit at flowers, causing fruit
production or the average number of fruits per plants to decrease dramatically.
Additionally, as per the Urban Wildlands
Group and UCLA Institute of the Environment, artificial lighting has been blamed
for decreases in populations of moths. By disrupting moth navigation and
suppressing flight, it interferes with mating, dispersal, and migration. It
also disturbs feeding, oviposition, nocturnal vision and, possibly, circadian
rhythms. It increases predation by birds, bats, spiders, and other predators.
Herein, artificial lighting is
increasing every year caused by ecosystem disruption, but currently, there is
no way to sort out.
Ref.: Nature 548(7666), 2017, Impact of
artificial lighting on moths(Kenneth D. Frank)
Jae Ho Lee, Ph.D
* Next week’s topic : Light and Plants(Circadian Clock in Plants - Part2)