Displaying items by tag: light pollution

The Midwest U.S. is seen in this image taken at night from the International Space Station. It's a good representation of the challenges presented by light pollution in the Southern Appalachians and beyond. NASA

Light pollution is disrupting the seasonal rhythms of plants and trees, lengthening pollen season in US cities

This story was originally published by The Conversation. Yuyu Zhou is an associate professor of environmental science at Iowa State University.

City lights that blaze all night are profoundly disrupting urban plants’ phenology — shifting when their buds open in the spring and when their leaves change colors and drop in the fall. New research I coauthored shows how nighttime lights are lengthening the growing season in cities, which can affect everything from allergies to local economies.

(Hellbender Press has covered light pollution, such as this great article from Rick Vaughan).

In our study, my colleagues and I analyzed trees and shrubs at about 3,000 sites in U.S. cities to see how they responded under different lighting conditions over a five-year period. Plants use the natural day-night cycle as a signal of seasonal change along with temperature.

The Southeast is seen at night from the International Space Station. NASA

Dark Sky parks, including some in East Tennessee, offer true views of heaven

“Look up at the sky. There is a light, a beauty up there, that no shadow can touch.”  J. R. R. Tolkien  

WARTBURG — Those who came before us read the night sky like we read maps today.  

In ancient times, pointing to the stars, they imagined creatures, mythological heroes and common every-day objects. Because of their fixed positions, the constellations became a foolproof way to navigate across vast, featureless deserts and expansive seas. The stars marked the changing seasons and the passage of time. The star patterns were memorized and taught to each new generation.