Why Light Pollution is Harming Tropical Forest Regeneration

Light pollution is a real thing that we should all be concerned about. Far from just being aesthetically displeasing, light pollution has been shown to have serious detrimental effects on nocturnal life on this planet. By blotting out the stars with night lights, humans are depriving many organisms the cues they need for activities such as navigation and breeding. It doesn't end there either. A 2014 paper published in the Journal of Applied Ecology has shown that light pollution is impairing rainforest regeneration.

How is this possible? Surely the light produced by man at night is not significant enough to affect photosynthesis and germination, right? The answer may not be as straight forward as one may think. The truth is, in many parts of the world, bats are important pollinators and seed dispersers. In the tropics, they are some of the only animals that will disperse seed (via their guano) into cleared patches of forest.

Researchers have found that when exposed to light, especially the kind used to light streets, buildings, and houses, bats were significantly less likely to spend time in those areas. This means less foraging and fewer seed dispersal events. Basically, as humans expand into these forested habitats and begin lighting up areas at night, fewer bats hang around and the forests suffer the brunt of this absence. As light pollution increases across the globe, I am sure that more and more of these types of relationships will be disrupted.

Photo Credit: Katja Schulz (http://bit.ly/1fou0OY)

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