Question

A researcher has been studying lichens in his hometown. Since he began his study, he has noticed several lichens dying in the vicinity of a new factory. What is most likely causing the decrease in lichen populations?

a. the diversion of water sources to the factory (i.e., lichens are drying out).
b. an increase in air temperature, the result of CO2 emissions from the factory.
c. the blocking of sun by the factory (i.e., the lichens aren't getting enough sunlight).
d. an increase in industrial pollutants in the area.

Answer 1

The correct answer is d. an increase in industrial pollutants in the area.

Step-by-step explanation:

Lichens are formed by the symbiotic association of fungi and algae. Lichens are found in diverse conditions from sea level to higher regions like tundra. They can grow on any surface.

Lichens are called pollution indicators because they do not tend to grow in polluted areas or polluted regions because lichens are very sensitive to pollutants like sulfur and nitrogen which are released by industries through their waste.

So the presence of lichens indicates the area is free from pollution and the absence of lichens indicates that the area is polluted. Therefore the right answer is d. increase in industrial pollutants in the area.