Old man's beard ( Usnea trichodea ) and yellow Evernia lichens are sensitive to elevated levels of ____.

Question

Quizplus · Accepted Answer

Old man's beard (Usnea trichodea) and yellow Evernia lichens are sensitive indicators of air pollution, particularly to elevated levels of sulfur dioxide. Sulfur dioxide is a common air pollutant that can harm lichens, which absorb water and nutrients directly from the air, making them highly susceptible to air quality changes.

Old Man's Beard ( Usnea Trichodea ) and Yellow Evernia