Excessive night lighting is now recognized as a form of pollution with the potential for causing damage to some trees. However, effects of supplemental lighting on trees are complex. Understanding tree response depends on the type of lamps used and the spectrum of radiation emitted, the intensity of that radiation, and the role of light in certain biological processes. [Cheney, William R. "Does Night Lighting Harm Trees?" Purdue University, Department of Forestry and Natural Resources]
